December Fastrack is out! [Archive] - Improved Touring Racing Forums

quadzjr

11-20-2009, 01:22 PM

So now we can run whatever sensors or air metereing devices we want, and chuck the stuff that came with the car?

"Item 1. Effective 1/1/10: Change section 9.1.3.D.1.a.6 as follows:
The engine management computer may be altered or replaced. A throttle position sensor and its wiring may be added or replaced. A
MAP or MAF sensor and its wiring may be added. Other existing sensors, excluding the stock air metering device, may be substituted
for equivalent units."

Ron Earp

11-20-2009, 01:27 PM

This is a clarification that appears in this fastrack:

1. Clarify section 9.1.3.D.1.a.4 by adding a sentence after the first sentence: “All air must also pass through the stock air metering
device, eg MAF, or AFM, etc if so equipped.”

JeffYoung

11-20-2009, 03:16 PM

No!

We changed that just to allow folks to add a MAF for systems that use a MAF.

You still have to use the stock air intake track, and the stock metering device must be there.

So now we can run whatever sensors or air metereing devices we want, and chuck the stuff that came with the car?

"Item 1. Effective 1/1/10: Change section 9.1.3.D.1.a.6 as follows:
The engine management computer may be altered or replaced. A throttle position sensor and its wiring may be added or replaced. A
MAP or MAF sensor and its wiring may be added. Other existing sensors, excluding the stock air metering device, may be substituted
for equivalent units."

JoshS

11-20-2009, 03:17 PM

924Guy

11-21-2009, 09:50 AM

Amusing note: talking about members/competitors unhappy with the shorter life of some safety harnesses. I'm glad that they do appear to be paying attention to us. I'm not so happy to hear that the information currently available is insufficient to make a decision one way or the other. Yet it was judged sufficient to change the rule a couple years ago.

At least they are taking the step to retain a professional auto safety expert to help resolve the issue.

Hope he/she's not an SFI member!?!

924Guy

11-21-2009, 10:07 AM

Don't forget also, in case anyone missed it - no more emails to the CRB for input, now there's a website form with tracking capabilities:
http://www.crbscca.com/

benspeed

11-22-2009, 10:12 PM

How the heck did the RX8 score that weight reduction???? Not loving that one bit :-(

Or more specifically - what was the criteria used that established this car should be at a lower weight than originally classed? That was over 100 pounds dropped...

JeffYoung

11-22-2009, 10:44 PM

Incorrect stock hp used initially. Lower than expected gain in IT trim, based on various dyno sheets received by the ITAC.

xr4racer

11-23-2009, 12:43 AM

The RX-8 is now classed as it should have been, hopefully people will bring them out and boost ITR's numbers. The weight is as low as you could possibly attain in IT trim with a 200lb driver. Next should be the Fox body Mustangs in ITR.

matt

RSTPerformance

11-23-2009, 12:53 AM

I thought it was against the rules to change a cars weight?

JoshS

11-23-2009, 01:12 AM

I thought it was against the rules to change a cars weight?

Not a newly-classified car. It's all spelled out in the beginning of the ITCS.

lateapex911

11-23-2009, 01:17 AM

Man, I don't know how many times I've typed this......

No changes to cars classified for 5 yrs or more. Adjustments ok for cars less than 5. It's in the ITCS.

Ben, relax. Think about it this way:
E36: known hp to the wheels, 217. weight 2760. tq? stout. brakes, vry good, handling, vry good.
RX-8: known power to wheels. 210-212. (215 was used), weight 2850. tq? tq? tq? Bueller? Bueller?. brakes and handling very good.

Further, word is it they go through transmissions like Dunkin Donuts goes thru coffee at 7AM on Monday mornings.

Still worried?
You coooould build that mill or yours, instead of carting around the 'club'. ;)

JeffYoung

11-23-2009, 01:34 AM

I have heard the grumbling about the Fox Mustang v. the SN94, and have to remind you guys that the "perception" the Fox is at a disadvantage to the SN94 doesn't mean it gets a weight change.

We still do use the process on new cars, and the classed Fox and SN94 cars have essentially the same specs......and the differences aren't things we account for in the process.

So, barring some evidence that the IT gain in hp is different between the two, they will stay at the weights at which they are set.

The RX-8 is now classed as it should have been, hopefully people will bring them out and boost ITR's numbers. The weight is as low as you could possibly attain in IT trim with a 200lb driver. Next should be the Fox body Mustangs in ITR.

matt

Ron Earp

11-23-2009, 09:32 AM

RX-8: known power to wheels. 210-212. (215 was used), weight 2850. tq? tq? tq? Bueller? Bueller?. brakes and handling very good.

Did you see the RX8 results in the latest issue of Sportcar? Fairly impressive and through a catalytic converter, 221 wheel hp. I don't know anything else than what was in the article and wouldn't think it'd amount to anything for the IT weight anyhow due to dyno differences and all that good stuff.

I have heard the grumbling about the Fox Mustang v. the SN94, and have to remind you guys that the "perception" the Fox is at a disadvantage to the SN94 doesn't mean it gets a weight change.
.

Man, I knew that putting those Fox chassis cars in that proposal was trouble. We were damned if we did, and damned if we didn't. I didn't want to put them in because of:

a) this hp/weight problem
b) people would be asking for brake allowances on the cars

Want to race a V8 Mustang? Race the SN95 chassis and like it, they are damn cheap to purchase. Just impossible to please all the people all the time.

Rabbit07

11-23-2009, 09:33 AM

How did the ITS Mustang weight get so messed up that it needed a 400 lbs break?

JeffYoung

11-23-2009, 09:38 AM

Because it was originally classed using the old "curb weight" formula, and not based on stock hp.

It was probably more "off" than any other car in the ITCS.

Ron Earp

11-23-2009, 09:58 AM

How did the ITS Mustang weight get so messed up that it needed a 400 lbs break?

I wrote the letter that ended up in that car's reclassification. The car has 140hp stock and there is no evidence to suggest that it'll gain any more in IT trim than any other car in ITS. It appears that it was classed as Jeff says using the old "rule of thumb" method that incorporated curb weight, and, then it was missed in the Great Realignment.

With the new weight I think the car could be a contender in ITS. Anybody wants to buy my Z I'll build one a ITS Mustang and let you know. :)

Ron

Rabbit07

11-23-2009, 10:02 AM

You may have a hard time getting the SN 95 car to 2470? I worked like crazy to get an fox body ITB car to 2600!

tom91ita

11-23-2009, 10:34 AM

How did the ITS Mustang weight get so messed up that it needed a 400 lbs break?

the domination of the ITS RX-7 at the ARRC?:)

spnkzss

11-23-2009, 10:38 AM

With the RX8 "fixed", all that needs is a drop for the S2000 and ITR is going to take off. :D

Ron Earp

11-23-2009, 10:51 AM

You may have a hard time getting the SN 95 car to 2470? I worked like crazy to get an fox body ITB car to 2600!

Yep, I have a feeling it'd be impossible. But, the process doesn't worry too much about that and at least the car has a chance at something lower than 2850 lbs.

benspeed

11-23-2009, 11:15 AM

I think the RX8 will now be much more of a threat at that weight of 2850 - Yep - time to get the 968 motor done over the winter. It'll be about 9/10s this spring. Right now its 8/10s at best - I think Kip has his S2 pretty close to 10/10ths.

Jake - just had the kart redone - bigger carb, better header :-) Now to find snow tires for it....my 12 year old son is almost faster than me - he can do a mean Joey Chitwood for about 20 feet

Tristan Smith

11-23-2009, 01:22 PM

How about taking a 100lbs off the 300zx........the RX8 I saw at Barber Motorpsorts Park this year looked pretty quick to me.

benspeed

11-23-2009, 01:53 PM

Tristan - you are likely more ticked about that weight reduction than I am. You pork out at 3250 or so for the 300ZX?

GKR_17

11-23-2009, 03:45 PM

It's all spelled out in the beginning of the ITCS.

No changes to cars classified for 5 yrs or more. Adjustments ok for cars less than 5. It's in the ITCS.

You both should definitely know better. Read it again.

The ITCS allows for weight changes based on on track performance after the second, third, and fourth year of classification. Not after the first.

Or is the CRB trying to call this an error? Maybe this is why we can't have a published process? Back to the old cloak and dagger system then?

Tristan Smith

11-23-2009, 04:19 PM

Tristan - you are likely more ticked about that weight reduction than I am. You pork out at 3250 or so for the 300ZX?

Yep, 3250lbs. I am sure when my car is "proven" not to be competitive they will adjust it, like they seem to have no problem doing, with the other cars. :blink:

Andy Bettencourt

11-23-2009, 04:33 PM

seckerich

11-23-2009, 04:40 PM

Andy what is the target HP for the 944?

Tristan Smith

11-23-2009, 04:49 PM

Tristan,

Your weight is based on 235ish whp in IT trim for a full build. If you think it can make that number, it's weighted correctly for ITR.

S2000 needs to make 225ish, RX-8 = 215ish, 968 = 223ish.

Andy, what is that based on? Just stock horsepower with the usual 15 percent improvement?

Andy Bettencourt

11-23-2009, 04:50 PM

205whp

seckerich

11-23-2009, 04:50 PM

You both should definitely know better. Read it again.

The ITCS allows for weight changes based on on track performance after the second, third, and fourth year of classification. Not after the first.

Or is the CRB trying to call this an error? Maybe this is why we can't have a published process? Back to the old cload and dagger system then?

Not true completely. The 2005 RX8 is now able to be classed with proper data so they were free to look at the numbers. It still makes 215 at best and is well within the process weight compared to the cars it will race against. I do think the S2000 and 300Z need to be looked at. No possible way the 300 can run with the ITR cars at over 3200 pounds. It may go down the straights but is will never corner or race well. I will write a letter supporting Tristan when you get that car on track. I don't think we need to get too upset until we see how they match up. Keep in mind the fastest ITR car at the ARRC still ran a slower lap than an ITS car.

PS. I sent cheesecake to all the CRB members in exchange for the weight break. Especially after all the nice things I said about them in the last year.:rolleyes: Yes, I am kidding.

seckerich

11-23-2009, 04:53 PM

205whp Thanks Andy, I knew the spec 944 was making an honest 200+ and figured more from the 944 in IT build.

Andy Bettencourt

11-23-2009, 05:07 PM

Andy, what is that based on? Just stock horsepower with the usual 15 percent improvement?

IT-prep improvements range from 15% to 50%. Standard number is 25% when there is no data to estimate with. The 300Z uses 30%, as do the 6cyl BMW's. Given the SSA 300XZ data we had to work with, those power levels should be very attainable.

Greg Amy

11-23-2009, 05:59 PM

xr4racer

11-23-2009, 06:56 PM

Ron, I saw the article in Sportscar. I do not know the difference in HP between the Dynojet and the DynaPack that they used. Maybe RX-8's with a good tune can make 218 or so but I do not think they will last. I also do not know how lean that car was tuned, I would imagine you could go leaner on an autocross car than a roadracer.

matt

Tristan Smith

11-23-2009, 07:30 PM

IT-prep improvements range from 15% to 50%. Standard number is 25% when there is no data to estimate with. The 300Z uses 30%, as do the 6cyl BMW's. Given the SSA 300XZ data we had to work with, those power levels should be very attainable.

If you ever get a free moment and think about it, would you mind sending me that info? I would like a look at it.

I think the ZX is going to be a pig regardless of the hp ratings. I think a lot the ITR cars are under "tired" for their weight. I never understood why the BMW's 8.5 wide rims were arbitrarily choosen for the class size. They may be common for that car but 9" rims would have been cheaper and more widely available. But, heck I have two sets now, so i don't want to change that rule! ha.

JeffYoung

11-23-2009, 07:37 PM

Tristan, pm me about that dyno sheet, it was for the car I own. Or better yet, shoot me an e-mail at [email protected].

Thanks.

Jeff

Dave Gomberg

11-23-2009, 10:03 PM

Hmmm. Just noticed they've changed the GCR 8.1.4 (compliance pre-review) process, and more than tripled the cost. Methinks the prior drop from $250 to a two-step review/appeal process (for $125/$175 respectively) probably garnered them a lot of customers...

Well, all that's gonna do is force it through the cheaper at-track protest/appeal process instead. :shrug:
Leaving aside your questionable arithmetic, the reason for the change is that almost everyone who has availed themselves of the 8.1.4 process has gone on to the second stage because if the first court found against them, they pursued the second stage in the hope (sometimes realized) that the CoA would overturn the first court, or if the first court found in their favor, they realized that without the CoA confirmation, they didn't have a bullet-proof approval. Because the second stage was not automatic, the total time to process a compliance review was increased while the person filing the request was contacted. The process had always been bundled until the last couple of years. The separation was put in place with the expectation that some would not use the second stage, but that didn't happen. So this is simply a reversion to prior practice.

Dave

Greg Amy

11-23-2009, 10:20 PM

...almost everyone who has availed themselves of the 8.1.4 process has gone on to the second stage...
...but not "all"? So, why not make it optional? Leaving aside your questionable arithmetic (the "prior practice" was actually $250, not $300) that cost is most assuredly a distinct disincentive.

What would I know, though: the last one we submitted wasn't even heard by the committee, sent back with a note that it should not have been submitted in the first place, implying that we were abusing the process (we now use the much lesser-expensive protest and appeal process).

...without the CoA confirmation, they didn't have a bullet-proof approval.Oh, you mean that "bullet-proof approval that reverts back to the GCR after the current calendar year...? I guess $300 just doesn't get you near as far as it used to...:shrug:

GA

P.s. Yep, you're right: $300 is only 2.4 times the cost of submitting the original $125 request, not 3x. My bad!

GKR_17

11-23-2009, 10:28 PM

Not true completely. The 2005 RX8 is now able to be classed with proper data so they were free to look at the numbers.

That's about as weak a justification as I've seen. Even so, that year isn't classed so it's clearly not true.

Ron Earp

11-23-2009, 10:39 PM

I think a lot the ITR cars are under "tired" for their weight. I never understood why the BMW's 8.5 wide rims were arbitrarily choosen for the class size. They may be common for that car but 9" rims would have been cheaper and more widely available. .

Yes, that is one aspect of compromise with ITR. When drafting the proposal we were told the 325 was the target car. That was bad in one respect for the wheel width, but more importantly it limited the hp and wt for the entire class. 189 stock hp was a bit "low" for the class and sort of forced ITR to be limited in scope.

In hind sight I'd have pushed (although I have zero influence) to keep the 325 in ITS at the correct weight, about 2800-2900 lbs, and left it out of ITR entirely. Heavy (relatively, but still very racable) in S would have only affected the BMW, but light in R limits the R class.

Wheels could still be opened up. Not enough R cars racing to matter. Write a letter.

Andy Bettencourt

11-23-2009, 11:22 PM

In hind sight I'd have pushed (although I have zero influence) to keep the 325 in ITS at the correct weight, about 2800-2900 lbs, and left it out of ITR entirely. Heavy (relatively, but still very racable) in S would have only affected the BMW, but light in R limits the R class.

Try 3170lbs in ITS.

Ron Earp

11-23-2009, 11:32 PM

Try 3170lbs in ITS.

Aren't you on a call? :)

Really, that high? I've not done the arithmetic for a few years but that seems a bit excessive, especially when considering the weight people wanted to put on the car years ago and "only" end up at 2900 lbs, without restrictor. Man, people were way more wrong than they thought.

3170 in S or 26XX in R? 500lbs difference?

Cheyne

11-24-2009, 12:21 AM

Want to race a V8 Mustang? Race the SN95 chassis and like it, they are damn cheap to purchase. Just impossible to please all the people all the time.

I have decided to build a ITR Mustang and will be using a SN95 that I just bought for the project. I should have it out sometime this summer. I do wish 17x9 wheels were a choice instead of 17x8.5 since the 17x9 is the common Mustang wheel. BTW I you are correct they can be had cheap. Found mine just south of Iowa City on Craigslist and paid $1200 for a 1995 Mustang GT with 95,000 miles. I figure it should cost me around $6k to $7k which is a lot better than the $90k I spend on my WCGT Mustang.

Cheyne Daggett

Andy Bettencourt

11-24-2009, 08:25 AM

robits325is

11-24-2009, 08:28 AM

Try 3170lbs in ITS.

How can it be so high? At that weight the 325 wouldn't even have a chance against the RX-7.

JeffYoung

11-24-2009, 08:35 AM

It has between 30 and 40 more wheel horsepower.

Andy Bettencourt

11-24-2009, 08:52 AM

How can it be so high? At that weight the 325 wouldn't even have a chance against the RX-7.

170lbs more than your car Rob, and how much more power?

924Guy

11-24-2009, 08:57 AM

Thanks Andy, I knew the spec 944 was making an honest 200+ and figured more from the 944 in IT build.

:o:blink::blink::o

Seriously??? RWHP?? Are you talking about a 2.7L??

Andy Bettencourt

11-24-2009, 09:16 AM

:o:blink::blink::o

Seriously??? RWHP?? Are you talking about a 2.7L??

I was talking about the ITR 944 S2

Dave Gomberg

11-24-2009, 09:25 AM

Greg:

FYI, prior to 2004, the fee for a ruling was $650. In 2004 it was lowered to $250 to encourage people to use the process. In 2008, when the process was changed to allow the member to choose to halt things after the first court's decision, the total fee went to $300. As I said already, the number of times the process was stopped before going to the CoA turned out to be so small that the CoA did not think the delays introduced outweighed any perceived advantages.

Dave

924Guy

11-24-2009, 10:08 AM

I was talking about the ITR 944 S2

Ah, OK, thanks - thought you were talking about 2.5L Spec 944's! :eek:

Fastfred92

11-24-2009, 12:25 PM

Ah, OK, thanks - thought you were talking about 2.5L Spec 944's! :eek:

No Vaugahn, the 944 NA is in permanent IT purgatory because it does not wear a Mazda badge on it's hood.....

Knestis

11-24-2009, 01:05 PM

Fred's back! Hey, Fred...

Kirk

Fastfred92

11-24-2009, 02:47 PM

Hello Kirk, Fred here continuing to lurk with economically clipped wings :(

billf

11-24-2009, 03:44 PM

I have decided to build a ITR Mustang and will be using a SN95 that I just bought for the project. I should have it out sometime this summer. I do wish 17x9 wheels were a choice instead of 17x8.5 since the 17x9 is the common Mustang wheel. BTW I you are correct they can be had cheap. Found mine just south of Iowa City on Craigslist and paid $1200 for a 1995 Mustang GT with 95,000 miles. I figure it should cost me around $6k to $7k which is a lot better than the $90k I spend on my WCGT Mustang.

Cheyne Daggett

Chenye,

I too am building an SN 95, 2002. Also hope to have it ready for the coming season. We should talk, to compare notes? I have had extensive experience with a Fox or two, and now will put it to good use in the SN 95.

write me at [email protected]

Bill:024:

Z3_GoCar

11-24-2009, 03:59 PM

Aren't you on a call? :)

Really, that high? I've not done the arithmetic for a few years but that seems a bit excessive, especially when considering the weight people wanted to put on the car years ago and "only" end up at 2900 lbs, without restrictor. Man, people were way more wrong than they thought.

3170 in S or 26XX in R? 500lbs difference?

Then where does this leave my 189hp car that's saddled with the weight of the follow on 194hp brother? Seriously, they're different blocks heads and intake manifolds, the only thing I can use between them is the head bolts. If you can tell it's a different motor just by opening the hood, shouldn't they be on a seperate spec line? Given that the VIN rule's no longer applicable, you'd think the motor is what determines the cars weight...

Ron Earp

11-24-2009, 05:00 PM

Chenye,

I too am building an SN 95, 2002. Also hope to have it ready for the coming season. We should talk, to compare notes? I have had extensive experience with a Fox or two, and now will put it to good use in the SN 95.

write me at [email protected]

Bill:024:

I'm happy to hear about all the Mustangs coming into ITR. I have heard of two ITR Camaros too. It means we did the right thing with the class and the SCCA has been hard headed for many years about domestic cars in IT. Ruin the look of R my ass........

Then where does this leave my 189hp car that's saddled with the weight of the follow on 194hp brother? ..

Well, that leaves you with deciding if you can get by with the lower displacement engine or if you'd like to step up to the other engine on the spec line. Or alternatively maybe you can write a letter and get them separated out into two weights. It is Christmas time you know.

JoshS

11-24-2009, 05:04 PM

Then where does this leave my 189hp car that's saddled with the weight of the follow on 194hp brother? Seriously, they're different blocks heads and intake manifolds, the only thing I can use between them is the head bolts. If you can tell it's a different motor just by opening the hood, shouldn't they be on a seperate spec line? Given that the VIN rule's no longer applicable, you'd think the motor is what determines the cars weight...

James, write a letter, we'll see what we can do.

For those who are wondering, the '97-'98 Z3 2.8 used the E36 328i motor (189hp), but the '99-'00 Z3 2.8 used the E46 328i motor (193hp), which is a different engine, albeit the same bore/stroke.

JeffYoung

11-24-2009, 05:15 PM

I agree, should be a separate spec line.

Not a significant difference in weight (60 lbs), but enough. Plus the line is just wrong.

James, write the letter and we will try to correct.

lateapex911

11-24-2009, 05:46 PM

yea, we gotta fix that. THAT is an error! Whoo hoo! ;)

JeffYoung

11-24-2009, 05:57 PM

A real one!

But wait, Josh is right...no errors and omissions clause in the GCR....lol.....

lateapex911

11-24-2009, 06:04 PM

:018:now now.
:rolleyes:

GKR_17

11-24-2009, 09:00 PM

For those who are wondering, the '97-'98 Z3 2.8 used the E36 328i motor (189hp)

Minor yes, but the early 2.8 liter engine is lsted at 190hp from the factory. The later aluminum block, double VANOS is listed at 193 stock. The original ITR proposal listed the stock power as 189, but back-calculating it appears the input was 191.

Z3_GoCar

11-24-2009, 09:36 PM

Minor yes, but the early 2.8 liter engine is lsted at 190hp from the factory. The later aluminum block, double VANOS is listed at 193 stock. The original ITR proposal listed the stock power as 189, but back-calculating it appears the input was 191.
Grafton,

You went for the iron block hp rating not the aluminum block introduced in 1997 not 1995.

http://en.wikipedia.org/wiki/BMW_M52 and http://en.wikipedia.org/wiki/BMW_Z3

Josh and I have discussed this in the past. I guess what changed is the relization that the car is classed based on the motor not the VIN, and if the motor "is" different enought that you can tell by an open hood then the weight should be too. (I always thought the 50lb on the e-36 and 100lbs on the e-46 328 was because of the trailing arm/multi-link rear suspensions.:shrug:) So then the max my car should weight is at least the 2765 (that's still 35lbs less lead than I'd have to put in it) that the 325 weights.

JoshS

11-24-2009, 09:58 PM

James is right. I should have mentioned that the '97-'98 Z3 wasn't exactly the same as the E36 328i ... the Z3 has an aluminum block version of the same motor (same internals, same head, same intake, etc.) but was rated 1hp less than the iron block version.

Z3_GoCar

11-24-2009, 10:12 PM

Thanks guys, I just submitted it and was given CRB #238 FYI.

NORRIS

11-24-2009, 10:25 PM

Good luck with that James.

I'd love to get some more ITR cars out there. I need someone to race against. Even if it's Mustangs and Camaros:happy204:

Z3_GoCar

11-24-2009, 10:41 PM

I'll be out reguardless of how this goes. I know you need some competition :D

GKR_17

11-24-2009, 11:58 PM

My bad, that motor is rated at 189.
Per the process the early Z3 should match the 325 weight as you say, while the later should be around 2820 lbs. Could run either motor with the VIN rule, or the 3.0 for that matter, though I doubt many would want to run that heavy.

Grafton

benspeed

11-25-2009, 08:07 AM

Andy Bettencourt

11-25-2009, 09:00 AM

Here's another question since some of our ITAC are on this thread. About a month ago I sent in a request to the CRB for proper weight specs for my 968 running in STU - never heard a word. What's the best way to get feedback on that question?

Looks like the GCR says 3300lbs Ben. But we wouldn't be the ones responding to your letter on that anyway. Not sure if there is a STAC.

Greg Amy

11-25-2009, 09:25 AM

...I sent in a request to the CRB for proper weight specs for my 968 running in STU...
Am I missing something here? The STU weights specs are a displacement-to-weight calculation, not specific to any vehicle (unlike STO). Alternatively, you can run under IT prep rules, meaning your already-defined IT weight...

benspeed

11-25-2009, 10:07 AM

I like Greg's answer better :-)

I found the weight to displacement grid in the GCR - 3300 lbs it is. Better to race STU in IT trim.

Seriously thinking about crashing the Runoffs in my Hillbilly RV.

Greg Amy

11-25-2009, 10:41 AM

Seriously thinking about crashing the Runoffs in my Hillbilly RV.
+1. See you at the National in April...

benspeed

11-25-2009, 10:49 AM

That's a 10-4 man - come chill in the RV and we can plot the Caddyshack invasion.

RacerBill

11-25-2009, 08:49 PM

Anybody know where we can get a group buy on boonie hats and Baby Ruths?

erlrich

12-21-2009, 09:27 AM

For those of you who don't frequent that other popluar watering hole, just wanted to mention that it has been confirmed that there will be a requirement for a H&N restraint for SCCA Club Racing beginning in 2012, and that all devices will be required to carry either a SFI or FIA certification.

Tristan Smith

01-28-2010, 11:53 AM

Quote:
Originally Posted by Andy Bettencourt http://www.improvedtouring.com/forums/images/chromium/blue/buttons/viewpost.gif (http://www.improvedtouring.com/forums/showthread.php?p=299086#post299086)
Tristan,

Your weight is based on 235ish whp in IT trim for a full build. If you think it can make that number, it's weighted correctly for ITR.

S2000 needs to make 225ish, RX-8 = 215ish, 968 = 223ish.

Andy, what is that based on? Just stock horsepower with the usual 15 percent improvement?

Hey Andy, I know i am digging up an old thread but..
after doing some leg work, and speaking with Jeff about that 235 WHP that was used to class that car, I need to ask for a clarification. Was only one dyno test used?

My discussion with Z1 motorsports, one of the leading Z shops in the country, puts that power of a basic IT build in the 200 hp range at the wheels.

Here is also a link to the 300zxclub website where people put up their dyno numbers with, again basic IT mods. It again supports the 195 - 205 hp at the wheels, numbers.

http://www.300zxclub.com/showthread.php?t=78732

So how would I go about trying disprove the one dyno sheet (that I know of) that was used to classify the car weight?

erlrich

01-28-2010, 12:50 PM

Andy, what is that based on? Just stock horsepower with the usual 15 percent improvement?

Hey Andy, I know i am digging up an old thread but..
after doing some leg work, and speaking with Jeff about that 235 WHP that was used to class that car, I need to ask for a clarification. Was only one dyno test used?

My discussion with Z1 motorsports, one of the leading Z shops in the country, puts that power of a basic IT build in the 200 hp range at the wheels.

Here is also a link to the 300zxclub website where people put up their dyno numbers with, again basic IT mods. It again supports the 195 - 205 hp at the wheels, numbers.

http://www.300zxclub.com/showthread.php?t=78732

So how would I go about trying disprove the one dyno sheet (that I know of) that was used to classify the car weight?

Tristan - I don't know this for a fact, but knowing how the process works I would guess they used the standard formula for IT-prep HP; for the Z it would be 222 stock HP * 125% = 277.5, then using the generally accepted drivetrain loss of 15%, you would get 236 HP to the rear wheels.

As for proving the car DOESN'T make that much HP, you're in for an uphill battle I'm afraid. Of course, on the plus side the way the CRB is doing things now all you have to do is build the car and run 4-5 seconds slower than the top cars, and you'll be eligible for a weight break :D I would do that with the Camaro, but it's already too damn light...

benspeed

01-28-2010, 01:11 PM

Tristan - I'm in the same boat although not as heavy with the 968. Based on the 25% gain I should make 236hp at the crank X 125% = 295 hp at the crank, less 15% driveline loss = 250 rwhp.

I am not remotely close to that number...but just had a top end motor job done so we'll see what she does on the dyno in a couple weeks. Regardless, there is no remote chance of 250 rwhp with a legal motor - even the FireHawk 968 cars make 235 at the wheels with race pistons, cams etc...

Ron Earp

01-28-2010, 01:24 PM

Hey Andy, I know i am digging up an old thread but..
after doing some leg work, and speaking with Jeff about that 235 WHP that was used to class that car, I need to ask for a clarification. Was only one dyno test used?

I might very well be wrong but I think 225 rwhp. Not that it makes a lot of difference, hell, it actually makes the classification situation worse if it was 225 rwhp....

Either way, fixing it in the current climate would be tough.

Jeremy Billiel

01-28-2010, 02:02 PM

Umm Ya.... Good luck with that.

erlrich

01-28-2010, 02:08 PM

My discussion with Z1 motorsports, one of the leading Z shops in the country, puts that power of a basic IT build in the 200 hp range at the wheels.

Here is also a link to the 300zxclub website where people put up their dyno numbers with, again basic IT mods. It again supports the 195 - 205 hp at the wheels, numbers.

http://www.300zxclub.com/showthread.php?t=78732

Looking at the numbers posted on the Z website, it might not be as far off as you think. There are guys putting up numbers in the 205-210 range with just IT-legal bolt-on mods; it doesn't look like any of them have touched the internals. It also looks like most of those are street cars, so they're probably still sporting most of the pollution equipment. I would bet you could get 220-225 out of a full-tilt IT build (including engine management & dyno tuning). 235...might be a little optimistic. Problem is, there is only one way to find out.

EDIT: just for the hell of it, I re-ran the weight (per the process) using 225 at the wheels (265 at the crank), and it looks like the car would probably have been about 140 lbs lighter had that number been used. Also of interest, using the 277.5 crank HP number it looks like the car received about 130 lbs of weight after the base weight was calculated; i.e. the car's weight would have been 3122 just using the ITR pwr/wt multiplier, yet it is classed at 3250. I'm guessing it got rewarded for great suspension & brakes????

Tristan Smith

01-28-2010, 02:20 PM

I guess I won't know for sure until I build a full blown engine. But even 220whp seems optimistic.

tnord

01-28-2010, 02:44 PM

i was under the impression these cars made BIG gains with IT legal prep?

my 1990 had 222 stock hp;

222 * 1.3 = 289 * .82 = 236 - 237 whp.
222 * 1.3 * 11.25 = 3247

222 * 1.25 = 278 * .82 = 227 - 228 whp.
222 * 1.25 * 11.25 = 3121

yes, 18% driveline loss is used for RWD cars.

lateapex911

01-28-2010, 02:44 PM

RWD cars have a 90 degree turn in the driveline that FWD cars do not, so the WHP is different. If you're going to do the math to back out the components, use 18% for driveline on RWD, 15% for FWD.

erlrich

01-28-2010, 02:55 PM

So the 300ZX was classed using 30% for the HP increase? Interesting....

JeffYoung

01-28-2010, 02:56 PM

Caveat -- I have an ITR 300ZX sitting in a storage shed.

What I know: the impression the motor makes big gains comes from a single dyno sheet on a car (my car I believe) from when it ran in SSA with a cat back exhaust. Supposedly made 225whp.

Like Tristan, I've not seen anything close to that in the research I've done, but the only way to find out is build an IT motor and see.

My guess is 225 whp in IT trim.

JoshS

01-28-2010, 03:29 PM

So the 300ZX was classed using 30% for the HP increase? Interesting....

It appears to me (I wasn't involved, so I don't know for sure) that only about 1/3 of the ITR listings were done with 25%. Most are at 30%. There are some at 20% and 15% too.

Ron Earp

01-28-2010, 03:46 PM

RE the 300zx - my cursory research showed that 200-210 rwhp might be hard to get BUT all that data I turned up was from the guys on Z boards who want to bolt stuff on and are strangers to the "every little IT mod is important and eventually adds up to big numbers". Didn't find anyone who had done the 0.5 compression, rings, hours on header design, etc. that it takes to make serious IT power.

In fact, the same Z guys laughed and called me a liar when I posted plots of our ITS Z's making 165-175+ rear wheel hp using stock cams and stock carbs. Go figure.

I bet a 300zx in 100% IT trim will be close to 225-235 rwhp.