ITAC News.

[JeffYoung]

Quite honestly, do you think that 50 lbs will have any significant impact in performance?

The flip side of this is that I'm convinced after looking at dyno sheets and having experience with making large displacement motors with low stock hp "work" in IT that the Vette's 350 is going to see big gains. The intake is an issue but that is not where IT flow improvements are seen. You need to scavenge and you put a great header design on that car and you are going to move the torque peak up a lot if the cam has some overlap.

I suspect you guys know this which is why the car is being built, and that's fine. You are entitled to the benefit of your hard work, and taking a chance.

But I think it very likely the car will make way more than 25% (but voted for it anyway because we don't have any real data to the contrary) and think keeping the DW adder in place for now is no real injustice.

[Chip42]

Again, much appreciated on the specifics...but help me with the math.

How would the S2000 lose weight by ops manual?

the 2.0L is under the "normal" displacement, so would loose some there (100#). the other doesn't.

And how would the Vette gain weight seeing as it already has 150lbs 'extra' for torque? Does the ops manual have a double whammy for displacement AND torque?

my mistake it's a tq/disp adjustment. to my knowledge, never applied other than the 5.o,5.7L etc... cars getting +150#.

Again, a separation between struts and DW is needed IMHO. Just get rid of the double application of the adder. The Vette is taking it in the ass on that front.

disagree. the strut adder ONLY affects FWD cars. it's not a 100lbs split RWD strut to RWD DW, it's 50. it's 100# to the FWD guys, so I agree we should do away with it. I think following the standard +50 foe DW formula is easier, so vote that way.

And PLEASE lets stop with the 'your' process stuff. I know you meant the 'collective' your...but I was the author of the deduction by % change. You see it in your ops manual now because of that regimes work. And frankly, that was one of the 'changes' that was on the pile when the CRB lost it's mind about the process.

no offense intended, but it's an easy to follow conversational reference to the process for which you are arguing, and which determined the bulk of existing ITR classifications. and believe me, I've kept up on the history. THANK YOU (and kk and jg and js etc..) fo getting us here. please don't be upset when we try to use the tool you worked so hard to leave us with.

the membership has access to the ops manual, and I think it's fair that they should be able to monday morning quarterback our work or a theoretical classification and get the same results we do. that's really the crux of the situation.

EDIT: Why would the TSX ever get consideration for +50 for suspension? I would hope it's a strut car or else it would have gotten the +50 just like the Vette. No?

it is a DW car and it did get +50, like the vette, though AFTER a -6% that -6%+50# is still a 25 larger weight break than the "old process" (better?) would have given it (-100 for FWD only).

while we're on the subject, can anyone from the realignment era committee explain the 100# weight break to the S2000 as shown in the spreadsheet under the "other" column?

[Andy Bettencourt]

Quite honestly, do you think that 50 lbs will have any significant impact in performance?

TOTALLY not the point Jeff. Any extra weight is a pain and a detriment.

The flip side of this is that I'm convinced after looking at dyno sheets and having experience with making large displacement motors with low stock hp "work" in IT that the Vette's 350 is going to see big gains. The intake is an issue but that is not where IT flow improvements are seen. You need to scavenge and you put a great header design on that car and you are going to move the torque peak up a lot if the cam has some overlap.

With all due respect, you need to do some more research on the intake and how crappy it is. Every engine has a bottleneck and if the intake is the weak area, there will be no huge gains to be had if you can't get enough air in to make a difference. Frankly, the routing sucks. Builds have been done on these for decades and all the hop-up stuff just isn't IT legal.

I suspect you guys know this which is why the car is being built, and that's fine. You are entitled to the benefit of your hard work, and taking a chance.

But I think it very likely the car will make way more than 25% (but voted for it anyway because we don't have any real data to the contrary) and think keeping the DW adder in place for now is no real injustice.

We THINK it can make 25% (mostly because a nice B&B on these older motors really tightens things up), have great torque, plenty of tire, and handle well. Issues of concern are HP, brakes, and and transmission (hoping the +3 business doesn't hurt the car). There is no way to do what you did with the TR8 as it doesn't have individual injectors, just 2 small throttle bodies injecting fuel into that manifold. Much like the old-school cross-ram carburated units of yesteryear.

It IS an injustice Jeff, no matter how small you think it is. Apply the process evenly to all cars. Now you know how ITR was built, either continue along that path or put the Vette on a +50 hold and get the rest of the class in line. That ain't going to happen in the next 3-4 months so do the right thing for the member who is building the car and get it in line with the class. Right now there is a 250lb difference in a car with excessive torque and a car with 'no' torque. It adds up.

[Andy Bettencourt]

while we're on the subject, can anyone from the realignment era committee explain the 100# weight break to the S2000 as shown in the spreadsheet under the "other" column?

LACK of Torque as compared to the class at that weight.

[Andy Bettencourt]

no offense intended, but it's an easy to follow conversational reference to the process for which you are arguing, and which determined the bulk of existing ITR classifications. and believe me, I've kept up on the history. THANK YOU (and kk and jg and js etc..) fo getting us here. please don't be upset when we try to use the tool you worked so hard to leave us with.

I'm just trying to explain to you why the weights 'make sense' amongst posts that they don't match up and are 'embarrassing'. Knowing how they were done brings most everything into line sans calculation errors.

[JeffYoung]

The individual car advocacy is starting to get a bit old honestly, along with the insinuation we are not trying to be consistent, don't know the history of ITR (Ron and I did the initial pass at that the spreadsheet and EArl Richards and I did the first attempt at a clean up in a lot of the inconsistencies in it after it was adopted) or just don't know what we are doing.

And yes, all of this is over 50 lbs and you are FAR too worked over it.

We'll do this the right way, in the best interests of the class, and as consistently as possible. Just like you guys tried to do when you were on the ITAC.

I'll also bet you $100 that motor makes more than 25%. I actually saw ZERO gain -- none -- with the individual cylinder tuning. Ron posted it in the Mustang thread, but the real gains with these low revving, high displacement motors is on the exhaust side.

[Andy Bettencourt]

Old to you maybe. But when a new car classification is done, differently than what has been done in the past, and it results in extra weight, it's an issue that needs to be resolved. We have discussed either of the ways it could be resolved. Neither are of consequence, just that applying the classing fairly is the ultimate goal. Not making a change either way - in the short term is, like it or not, a fail in consistency.

1lb or 200, it doesn't matter. You want to strive for consistency, here is your chance. Sorry if you are taking offense, but you guys made an error you didn't know you made and it would be nice if you fixed it.

I know you will fix it, with the best intentions of the class, but if you think it's going to be 6 months to a year to get ITR cleaned up, the fair thing to do would be to admit you applied the DW in ITR not realizing that's not how the class was created and give the car a break so you don't double-whack it, until a class-wide correction is done.

The individual car advocacy is starting to get a bit old honestly, along with the insinuation we are not trying to be consistent, don't know the history of ITR (Ron and I did the initial pass at that the spreadsheet and EArl Richards and I did the first attempt at a clean up in a lot of the inconsistencies in it after it was adopted) or just don't know what we are doing.

And yes, all of this is over 50 lbs and you are FAR too worked over it.

We'll do this the right way, in the best interests of the class, and as consistently as possible. Just like you guys tried to do when you were on the ITAC.

I'll also bet you $100 that motor makes more than 25%. I actually saw ZERO gain -- none -- with the individual cylinder tuning. Ron posted it in the Mustang thread, but the real gains with these low revving, high displacement motors is on the exhaust side.

I would happily pay on behalf of the builder. It would be awesome! I guess all of these motors will act exactly the same so I hope to get the same gains you got.

[Chip42]

LACK of Torque as compared to the class at that weight.

ah, roughly consistent with the ops manual. I can work with that. why didn't the type R get this? before other adders, from the math used when classified:
type R: 195*1.2*11.25 = 2635, tq = 131 lbft (factory) -> 20.1 lbs/lbft tq
S2000 (2.2L): 240*1.15*11.25 = 3105, tq = 162 lbft (factory) -> 19.17 lbs/lbft tq.

that means that the teg has less torque to weight than the S2000, and a smaller engine than is the norm. I'm sure a 100# deduct (after the FWD 6%) would be consistent:

see my next post, and andy's - got the math wrong here.

Corvette's numbers? 10.6 lbs/lbft and 12 lbs/hp at 3085# (205 hp, 290 lbft, 1.25 gain, +150tq/dipslacemnt, +50 DW)

certainly looks fair to me (small sample, but still) and it doesn't even take into account the torque gains in IT trim, which I'm betting the 'vette and other big-bore engines will get more of than the zing-bang hondas.

thoughts?

[Andy Bettencourt]

Run those Vette numbers again?

205x1.25.11.25+150=3033--->3035

+50 for DW (that no other car in ITR gets) = 3085

I don't understand your other numbers. 'Adjusted crank hp'?

S2000 is 276hp estimated crank in IT trim / 3005 is 10.88
Vette is 256hp estimated crank in IT trim / 3085 is 12.05
Type R is 243hp estimate crank in IT trim / 2535 is 10.38

This is totally congruent with the extra 150 for torque not factored. Torque to weight can be done too. Your S2000 numbers need some freshening up.

[Chip42]

Sorry - 3085, just verified the number we recommended ans that's it.

My pwr/weight for the hondas was wrong and I fixed that (below). also, I used the ops manual process weights to prove a point, which remains valid.

don't know where the other numbers came from, didn't save the calcs. pwr/wt numbers for the vette stay the same (changes in the hundredths).

summing up:
teg R (195*1.2=234 process hp), 2425#, 10.4 lbs/hp, 18.5 lbs/lbft
S2000 2.0L (240*1.15=276 process hp), 3055#, 11.1 lbs/hp, 20.0 lbs/lbft
S2000 2.2L (240*1.15=276 process hp), 3055#, 11.1 lbs/hp, 18.9 lbs/lbft
84 Vette (205*1.25=256 process hp), 3085#, 12.0 lb/hp, 10.6 lbs/lbft

the point is that the ops manual numbers WORK here, and as expected the big torque cars are still strong in terms of weight/tq EVEN AT "HUGE" WEIGHTS. current classification for FWD puts many of them at a weight deficit, the low displacement/torque deduct is missing "randomly" (from the data I have), etc..

benefits: this system seems to work, well. members can understand it because its already published. reworking the cars will balance the field better (based on these numbers). consistent with the rest of IT processes. many cars lose weight.

down side: some classifications will change, some cars gain 50lbs.


we will be rerunning the numbers even if we don't end up recommending them. I will share my portion of that effort here and to anyone who asks.

[Chip42]

Y'all keep talking about adders and subtracters for FWD and RWD based on what it does to handling. One area not addressed is RWD with engine in the rear - a real negative for handling. How about re-considering what should be done with the Porsche 911 models in IT-S and IT-R?
Is this the Rant guy -> :026:

I tend to agree but not likely to see that happen. sorry. if it makes you feel better, I have to carry 50lbs in my MR2 for having a mid engine.

[benspeed]

Watching the forums here and in STL the engineers are good at engineering the classes...I will pay you to get power to weight competitive Instead of the pro Porsche shops....light is better. I make the same power as the s2 cars and they run at 2810 vs 3055.

Who wants the retainer?

[Andy Bettencourt]

we will be rerunning the numbers even if we don't end up recommending them. I will share my portion of that effort here and to anyone who asks.

Please re-run and apply as consistently as you can. Let's not have only one car get a DW adder. Again, I see no downside to running the Vette congruent with other cars in class until you decide how to clean up ITR/Ops manual.

[JeffYoung]

Why would you think we would NOT apply as consistently as we can?

C'mon now, some of this is getting silly.

Please re-run and apply as consistently as you can. Let's not have only one car get a DW adder. Again, I see no downside to running the Vette congruent with other cars in class until you decide how to clean up ITR/Ops manual.

We've had the DW discussion on the committee. I don't think the committee's opinion is going to change. In my opinion, we are starting with "doing it right" with the Vette. If we do it your way we are going to see the weight change on that car two times over a six month period or so, and the CRB is going to ask (rightfully so) what the hell we are doing.

Yes, there is a downside and yes, there is a bigger picture than this one car.

[seckerich]

Where does the RX8 fall in your new number crunch? Need to decide if I get new glass or lexan.

[JeffYoung]

Struts up front, multi-link rear right?

Shouldn't change at all if so.

[Ron Earp]

RX8 is Mazda double wishbone upfront if I'm not mistaken. Multilink rear.

[Andy Bettencourt]

If we do it your way we are going to see the weight change on that car two times over a six month period or so, and the CRB is going to ask (rightfully so) what the hell we are doing.

Yes, there is a downside and yes, there is a bigger picture than this one car.

And you can tell them the truth. That you went by the flawed Ops manual, didn't recall how cars were classed, and applied an adder when the class didn't currently call for it.

So you humbly admit this, bring the one car in line until the ITAC and the CRB align on a re-do of the whole class. Why? Because the simple fact is you should be considering a strut decuct at these weights instead of a DW adder. But that is just a time and committee thing, I don't so much care either way as long as the class is aligned.

It's really the most simple and fair thing to do. I can't see how you would see it any other way that to avoid a slightly embarrassing situation for the ITAC, unless the ITR redo was published in the next couple months, but that ain't how fast things can get done. ESPECIALLY considering the perceived desire of the ITAC to stabilize the rules for a time-period.

RX-8 is DW front.

[StephenB]

LACK of Torque as compared to the class at that weight.

So with the RX8... did we get the 100# deduct for lack of torque?
I REALLY wish they would use the SCCA forums to post HOW a car is classified and WHY. Not the process but list each new classification similar to an online journal for ALL members to reflect back on. Then we would have all known which cars got a 100# deduct. I honestly had no idea any cars got that.

RX8 is Mazda double wishbone upfront if I'm not mistaken. Multilink rear.

Ron you are correct. ITAC Should I plan to add 50# or 25# since the car is only 50% DW?

Stephen

[Andy Bettencourt]

Ron you are correct. ITAC Should I plan to add 50# or 25# since the car is only 50% DW?

Stephen

Currently the adder is for front only.