Race built engine - what improvement could be expected?

[gran racing]

Currently I race with a stock engine that has a lot of miles on it (around 190,000). I also have a parts car / engine that is currently just being stored for a rainy day. I was speaking with someone that builds engines and might be able to work out a barter arrangement to have him build an engine for me. It still would cost me some money, but relatively speaking it would be pretty darn cheap.

How much time could I save by getting a race built engine? (not touching anything else) Based on talking to other Honda people, it seems like it might be possible to gain another 20 HP (not sure if at the wheels or crank).

At this point in time, I am not going to sell my car and get a "real" race car. It simply isn't something that I could sell my wife on. But the barter idea is something she would go for...

[ITSRX7]

What kind of engine for what car in what class?

AB

------------------
Andy Bettencourt
06 ITS RX-7
FlatOut Motorsports
New England Region #188967

[gran racing]

It is for a 1987 Honda Prelude si. Currently classified in ITA.

110 HP stock at crank. Min. allowed weight 2,450 lbs. And I do realize that I still would not be near the front runners in ITA, but it would put me more in the mix of things / possibly more fun. IF it got reclassified in ITB, it might be competitive. I am really basing my decision as if it were to stay in ITA.

As we all know, the 1993 VW Golf 2.0L got moved to ITB. It has 115 HP and min. weight of 2,350 lbs. There are also several other cars that have better weight/hp rating then the prelude. The Prelude was also newly classed this past year, so they might consider it.

For example at LRP (or other tracks), how much time do you think I could cut from my lap time with the extra HP?

[ITSRX7]

LRP is a momentum track. I wouldn't think you would see the kind of improvement that you would see at an NHIS or Pocono where power is important.

If you are running a stock motor, 110 crank hp tranlates to roughly 90 wheel hp. I would be that a full-on IT motor could easily net you 20 more wheel hp or about 135 crank hp (all assuming 18% driveline losses).

Only the people who have done it can give you estimates on lap time improvements. That is a rare bird in ITA.

AB

------------------
Andy Bettencourt
06 ITS RX-7
FlatOut Motorsports
New England Region #188967

[Bildon]

I'm not a Honda guy, but on most engines +10-15% is normal for IT prep. If you get closer to 20% gain, you've either removed a huge engineering fault or you've cheated http://Forums.ImprovedTouring.com/it/biggrin.gif

Now if you want to start, tuning headers, exhausts, electronics...there is more to be had. However you stated only an engine rebuild.

- Bill

[gran racing]

Hopefully the bird will migrate to ITB.

Thanks for the input...
Dave

[ITSRX7]

Remember Bill, we are dealing with Honda's here. The 108hp 1.6l ITA CRX makes 125 at the wheels with all the right parts.

Each engine is different but the Honda's and BMW's seem to be more than the sum of their parts. Not to mention that the Wankel's do great considering you can't do anything internally besides a balance.

Take the car to a dyno and if you like the power, concentrate on the driving.

AB

------------------
Andy Bettencourt
06 ITS RX-7
FlatOut Motorsports
New England Region #188967

[Banzai240]

Originally posted by Bildon:
I'm not a Honda guy, but on most engines +10-15% is normal for IT prep. If you get closer to 20% gain, you've either removed a huge engineering fault or you've cheated http://Forums.ImprovedTouring.com/it/biggrin.gif


Numbers I've seen for most front running IT cars would show closer to 20-25% gains... And these are legal, but taking full advantage of IT prep rules (i.e.: + 0.5 compression, .040" over, etc...)



------------------
Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX
http://home.comcast.net/~djjordan/Web/DJ_AV1.jpg

[OTLimit]

We would love to see a 20% gain. Legally, of course.

------------------
Lesley Albin
Over The Limit Racing
Blazen Golden Retrievers

[Bildon]

hmmm, perhaps Chris and I should be racing poorly engineered cars so we get a bigger boost from the IT prep http://Forums.ImprovedTouring.com/it/biggrin.gif

- Bill

[Banzai240]

Originally posted by Bildon:
hmmm, perhaps Chris and I should be racing poorly engineered cars so we get a bigger boost from the IT prep http://Forums.ImprovedTouring.com/it/biggrin.gif

- Bill

You guys are breaking my heart...

Let's see... doesn't an ITC VW make about 75 hp stock? Assuming a 25% improvement with IT prep, that makes about 94hp...

Since a 510 makes 96 hp stock, and I KNOW that it's actually good for about 115hp with IT prep, AND a good VW can whip a good 510 on most days, I kind of have a hard time believing that those ITC VWs aren't making at LEAST a 25% improvement...

I'd be interested to know what a CRX in ITC makes for power... Anyone want to be it has the best wt/pwr ratio of the group???

------------------
Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX
http://home.comcast.net/~djjordan/Web/DJ_AV1.jpg

[This message has been edited by Banzai240 (edited February 17, 2004).]

[lateapex911]

DAve, just so you have another data point in ITA, I dynoed my RX-7 on two occasions, on two different dynos. The numbers were identical.

The second time was at Lime Rock after a race. If I recall, my lap times were probably around 1:05, (Never have had the car in the 3s) and the RWHP was 104.

I was just over min weight. The car came stock with about 100-110 SAE hp. So 2390/104= 23 lbs per hp. Pretty sad, actually! (i'm told that closer to 120 is possible with a well built rotary, which would be about 20lbs/hp)

------------------
Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[Banzai240]

Originally posted by lateapex911:
(i'm told that closer to 120 is possible with a well built rotary, which would be about 20lbs/hp)

Jake,

With 104 rwhp, assuming at least an 18% parasitic loss, your making 122hp at the flywheel... Now, that's only a 10% gain...

I think you might need to get a new engine builder (no offense, but seriously...), because the rotary numbers I've seen (yes, real numbers) show more on the order of a 20% gain... and that's legal power... You have to step up beyond just an average rotary build to get there, however...

I agree, however, that the RX-7/3/4 need some help in the current crop of ITA cars... We're working on it... We're working on a lot of things right now...




------------------
Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX
http://home.comcast.net/~djjordan/Web/DJ_AV1.jpg

[gran racing]

I can't wait to see what happens with IT cars! I'm really hoping that my car will be moved to ITB - should be on the agenda for the next meeting.

I know someone else that is really hoping for the same results for his '87 MR2.

I know it is a ton of work for SCCA and might create some tension, but think it will be for the best in the long run. But that is a different conversation...sorry.

If I get the engine done, I assume I should (need to) get the ECU modified?

Interesting...the other post in general discussions about buying a front running car. Is there any point (at least in ITA)? Based on that info. and what I've seen, the difference between a top 1/3 pack car and a winner are pretty substantial. So, if I could run mid-pack (ITA or ITB) with my current car & a good engine, is it worth spending all of that extra money to get a few cars closer? I know that's a question we all need to answer for ourselves.

[gran racing]

multiple post clean-up

[This message has been edited by gran racing (edited February 18, 2004).]

[gran racing]

multiple post clean-up

[This message has been edited by gran racing (edited February 18, 2004).]

[gran racing]

multiple post clean-up

[This message has been edited by gran racing (edited February 18, 2004).]

[Banzai240]

Originally posted by gran racing:
I'm really hoping that my car will be moved to ITB...

I know someone else that is really hoping for the same results for his '87 MR2

I'm sure you are all aware that a move from ITA to ITB is going to involve buying a new set of wheels, because the 6" wheel-width requirement is still there, and is likely to remain there for the forseeable future...

I personally would think that a chance to be more competitive would be worth the trade-off in wheels, but I would be interested to know how most of you who might find yourself in this situation feel about this?

------------------
Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX
http://home.comcast.net/~djjordan/Web/DJ_AV1.jpg

[gran racing]

Darin,
The 1987 prelude si was newly classified last year in IT. I've spoken with the other people that run the car and none of us have bought 7" wide rims yet. Most of are using 5 1/2" or 6" rims. Guess that is one good aspect of not having much to choose from with 13" rims. http://Forums.ImprovedTouring.com/it/smile.gif

I do have a lead on some 13" x 7" steel wheels, but will wait till I hear how the request goes. Because it was just classified last year and this will be a review after one year of the car running, it might have a shot.

As for other people - I know Jake who runs the MR2 wouldn't be too upset about the change (to say the least). Buying new rims is a small price to pay to be more competitive.

But yes, you definately raise a good point when talking about other cars and reclassifying them. I still believe that the majority would make the sacrifice. Thanks for taking that into consideration.

(sorry for the multiple posts before - don't know what happened)

------------------
Dave Gran
NER #13 ITA
'87 Honda Prelude

[Jake]

I'd buy 6" wide wheels in a heartbeat.

[lateapex911]

IF cars get moved between classes, (A to B), I would submit that it makes more scientific sense to move them with a line item allowing the continued use of 7" rims.

I assume some cars will need a weight adjustment. OK, thats fine, as it can be done apples to apples....I'll use my car as an example. Lets say my times are top dog at most tracks when I compare them with ITB times. (OK, I'm dreaming, but bear with me!) So the rulesmakers might want to add a little weight. Fine. But if you also change the wheels at the same time, how can you confidently predict performance? And how do you decide what to add for weight?

And for a lot of guys, it is a serious budget item. The standard quiver is 3 sets of wheels, and a set of rains mounted.

In the end, I agree that the big picture is important, and that a signifcant "trickle down" needs to occur. But I think that the bottom line is the on track performance, regardless of wheel width. Throwing away known performance is, in my mind, a questionable action, especially in light of the bugetary concerns.

That said, if you asked me whether I wanted to stay in A, at my current weight, and race against the big 4 at their current weight, or be moved to B on 6" wheels, I would, begrudingly, put B stickers on my car. I say that assuming that the CRB will be making significant moves of cars from S to A, such as the Neon, the NX-2000, The SE-r, and so on. But ask me tomorrow, and my answer might change!

------------------
Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[Jake]

Just to add a little pragmatism into the mix: My 14x7 wheels (FWD 4x100) can be easily sold as they will fit many ITA/S cars. However, if the RX7 migrates to B (as it should) a large investment in RX7 13x7 RX7 wheels will much more difficult to recoup.

[Joe Harlan]

So why not class the car with both widths and put a premium on the 7" stuff say an extra 10 lbs per wheel ? or some thing like that. Aren't the Pro7 and Spec7 cars already on 6" wide wheels?

[gran racing]

Now we are talking about two different things here - a true reclassification request and a competition adjustment. Similar, but I do think there is a difference. What I ('87 prelude si) and Jake ('87 MR2) are looking for is a reclassification. Same weight (no adjustments), follow ITB rules (6" wide rims) ectera. There are some cars out there that should simply be reclassified and others that could be reclassified but at the same time would require an adjustment in the min. weight allowed. The first is a bit easier than the second. Not saying that both shouldn't be addressed in the future.

Darin definately brought up a very valid point about wheel changes due to the smaller width. At the same time it would be difficult / probably unfair to change the rules in ITB to allow 7" rims. Why should the cars that are staying in a class / not receiving a benefit be penalized by another car getting reclassified (or a comp adjustment)? While the move is valid and very necessary in several circumstances, the existing ITB cars shouldn't bear the cost of the change. (And I'm not saying that's what you were getting at, but a related conversation)

My sincere hope is that if the SCCA decides to utilize competition adjustments, it still really looks at the classification and doesn't over utilize the weight reduction / addition. As an example, we have done a lot to try and get Jake's MR2 down to its min. weight. From stripping the car to draining all windshield washer fluid. With his MR2 year (different MR2 years can reach the min. weight), it simply isn't very feasable to obtain the min. weight. In that particular car's case, it would be pointless to simply keep the car in ITA and reduce the min. weight from what it currently is. There are many other situtations like this one.

------------------
Dave Gran
NER #13 ITA
'87 Honda Prelude

Darin, 20% gain for an rx7 although possible is not feasable unless you only race for 5 laps. I was at 117 RWHP all last year and was getting killed on the straights by other 7's, so I tried a setup that leaned out the top end and got 125-128 RWHP (unpredictable), and promptly blew the motor on the second lap. from here out im running on the safe side of the tuning gains ratio, one side housing was all I saved from that last mistake.

[This message has been edited by 7'sRracing (edited February 19, 2004).]

[Banzai240]

Originally posted by 7'sRracing:
[B]Darin, 20% gain for an rx7 although possible is not ... I was at 117 RWHP all last year .... so I tried a setup that leaned out the top end and got 125-128 RWHP (unpredictable), and promptly blew the motor on the second lap[.../B]


Well, you just contradicted yourself...

117RWHP + 18% for parasitic losses = 138hp which is EXACTLY what I stated. If this is on the safe side, then I was wrong... maybe 25% is more accurate.

Then you tell me that the other RXs were faster... did they run for the whole race?

There is more to getting power out of a rotary than leaning it out... There's more power there than can be achieved with your typical Racing Beat header... There is more power there than can be achieved with your typical exhaust system... than your typical Mazda ignition... etc...

Also, at a track like Portland, where I usually race, there's the biggest factor of all... In a drag race, my car was faster than it's sister car, but in a race, even if we were side-by-side at some point in the corner, he would pull me by a couple of car lengths down the straight... No offense, but the you may not be getting all you can out of what you have...

All that being said, I completely agree that the RX-7s need some help...



------------------
Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX
http://home.comcast.net/~djjordan/Web/DJ_AV1.jpg

[Banzai240]

Originally posted by gran racing:
My sincere hope is that if the SCCA decides to utilize competition adjustments

Let me clarify something. I have NOT heard ANYONE on the ITAC suggest that we do ANYTHING in the way of "Competition Adjustments", beyond using weight and/or reclassifications. I do not expect that wheel width allowances are going to be changed, and I am pretty certain that there are NOT going to be any cars moved to ITB with a 7" wheel width allowance.

I think it is safe for me to say that the goal is to keep the integrity of the IT rules, both in spirit and intent. We are discussing minor, strategic adjustments to help revitalize/modernize the class and increase it's popularity, but on whole, the class philosophy, intent, and traditions should continue.

Basically, we are doing our best to not screw things up! http://Forums.ImprovedTouring.com/it/wink.gif

Stay tuned...

------------------
Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX
http://home.comcast.net/~djjordan/Web/DJ_AV1.jpg

ok, points taken, I was never a math major http://Forums.ImprovedTouring.com/it/smile.gif
and yes there were some other motors puking and some going the distance and yes I guess I could build a set of headers on the dyno. But, then again im just a average schmuck trying to race on a budget. I tweaked the motor to see if I could even get a glimps of their tail lights at the end of the straight.
I never got a chance to find out, was still in traffic when it let go.

[Racy-Stacey]

Since you guys talked about power to weight ratio..

Is there a good rule of thumb or a number that is concidered acceptable(competitive)?

20? 21? 22? 23? 24? 25?



------------------
Toodles,
Stacey_B AOL IM: SCCAStaceyIB 1990PGL (http://www.scpoc.com/Car%20Profiles/stacey.htm) SCCA STSL "Girls Do It Better" Cal Club T&S, BWRP,WS,Lag,Hallett www.scpoc.com (http://www.SCPOC.com) : www.probetalk.com (http://www.probetalk.com) Racing is my life. Winner One Lap of America 2003- SSGT2 class 1996 Ford Probe GT.

[gsbaker]

10 would be a good number!

At the PRI show in December I saw a slick new sports racer that works the power-to-weight ratio very hard. With a 180hp motor it tipped the scales at 750#.

Let's see...carry the 2...times pi...raised to the 2/3 power... Yikes! 4.17#/hp!

Of course, you would need a second mortgage to pay for all the CF...

Gregg

The YZ 250 (actually 330 cc) I last raced in 99 with me on it had a 6.1 P/W ratio. I really miss it.

[x-ring]

"...to pay for all the CF..."

CF?

Ty

[theenico]

CF = Carbon Fiber = empty wallet http://Forums.ImprovedTouring.com/it/smile.gif

------------------
Nico
KCRaceware (816) 257-7305
[email protected]

[lateapex911]

Originally posted by Racy-Stacey:
Since you guys talked about power to weight ratio..

Is there a good rule of thumb or a number that is concidered acceptable(competitive)?

20? 21? 22? 23? 24? 25?



Well, it depends on the class. If you're considering racing a car that hasn't seen much action in a certain class, figuring out it's P/W ratio is one data point that can indicate it's potential performance.

For example, in ITA we all know that the CRX is a top dog, and it races with about 125 hp at the wheels. At it's racing weight of 2140, the result is 17.12 . Compare that with my RX-7, which has (theoretically!) 118 hp at the wheels, and races at 2380, for a P/W ratio of 20.17, and you can see that the RX-7 will need distinctly better handling (uh-oh), better brakes, (oh jeeez..) or better torque (what was I thinking!?) or some other combination of characteristics to run at the front.

Just a wag here, but in ITA, 17 or 18 is a good number with solid handling and braking, and in ITS, the number looks to be in the 13?-14 to 15 range. I say "13?" because getting folks to admit actual numbers is tough, but I bet the faster E-36s are in the 13s.



------------------
Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

I liked my 6.1:1 better but my $7000 racer cost my insurance company a $30000 surgery.

[Racy-Stacey]

I was thinking for ITB. : )

Thanks....

[JeffYoung]

Not sure what this means (maybe the Hondas aren't as developed as they should be) but we have one 12A RX-7 here in the SEDiv who is faster than any ITA car.

[oanglade]

Originally posted by lateapex911:

... but I bet the faster E-36s are in the 13s.




From what I've heard, try "under 12" for size.




[This message has been edited by oanglade (edited February 24, 2004).]

[TypeSH]

Originally posted by oanglade:

From what I've heard, try "under 12" for size.


Are you talking crank or wheel horsepower? To get under 12 you would need ~240hp in a 2850lbs car. I can beleave they are getting 240hp crank but not 240hp to the wheels.

[lateapex911]

No, there is no way an E-36 is putting 238 down at the wheels! What did they come with stock? 190? At the crank! I think the rumoured 217 is pretty respectable....

IF they did, it would be obvious, as the 7s are putting down what, 180? And THAT'S being optimistic. No way they could even SEE the bimmers after 4 laps if the bimmers were putting down 238!

As for ITB, anybody care to toss out some numbers? How about you RST guys....you're being unusually quiet!

I would GUESS that a good ITB number might be 21- 22?

------------------
Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[This message has been edited by lateapex911 (edited February 25, 2004).]

[oanglade]

Originally posted by lateapex911:
No, there is no way an E-36 is putting 238 down at the wheels! What did they come with stock? 190? At the crank! I think the rumoured 217 is pretty respectable....

IF they did, it would be obvious, as the 7s are putting down what, 180? And THAT'S being optimistic. No way they could even SEE the bimmers after 4 laps if the bimmers were putting down 238!



Well, that's the talk around my town. I really don't know for sure.

At the same time, the same talk is of Spec Miatas (Showroom stock engine rules) with over 120hp at the wheels. I know those numbers are real so who am I to doubt the BMW numbers?
Just take it as a rumor, I guess.

------------------
Ony Anglade
ITA Miata
Sugar Hill, GA

[Knestis]

So what ARE the cam pulley keyway tolerences on a Miata?

With that type of cam drive system (we learned this playing with 16v VWs), a clever person can adjust not only the overall valvetrain advance but the relative rotational position - overlap - between the intake and exhaust cams.

That's a "racing cam" to you and me, Rusty.

What kind of cam drive does the e36 have?

Kirk

(who knows that there is a Mercedes P/N offset cam pulley key that fits the MkII GTI but hasn't purchased one for his MkIII...

[oanglade]

How good is the BMW's ECU mapping? Would they/Do they benefit a lot from stuffing a really cool ECU in the stock box?
Do the 325's have that "VarioCam" deal or is it only the "M"'s?

I think the BMW's were already running away from the RX-7s last year on horsepower tracks. Just for a quick example, look at the ARRC qualifying. The top RX-7 is almost 3 seconds from the pole sitting BMW. And that was last year.

How a Neon, Sentra or Miata is supposed to have a chance at being able to compete with cars putting over 240whp is beyond me.


------------------
Ony Anglade
ITA Miata
Sugar Hill, GA

[RSTPerformance]

Originally posted by lateapex911:
As for ITB, anybody care to toss out some numbers? How about you RST guys....you're being unusually quiet!

I would GUESS that a good ITB number might be 21- 22?



Well it is tough to say since I we have never ever done any dyno time ever on our cars. http://Forums.ImprovedTouring.com/it/frown.gif I would love to but the money equals an entry fee!

I would guess our cars come in around 110HP at the wheels and they weight in at 2490. so That would equal 22.6.

Seems good to me! The cars have a ton of tourque to get you out of the corner as well which helps a ton at places like NHIS or the boot at the glen! I wish we had some real data for you. That's the only reason we didn't post because it is definitely a guess at best.

Stephen



[This message has been edited by RSTPerformance (edited February 25, 2004).]

[gran racing]

Hmmm. Very interesting! That's about what my Honda Prelude would have if I got a built engine. Stock HP 110; weight 2,450 lbs.

Out of curosity, what type of times do you run at LRP? Not best ever, but typical times? (just curious how far off I am right now)

------------------
Dave Gran
NER #13 ITA
'87 Honda Prelude

[ITSRX7]

Just to clear up some numbers, these are from ACTUAL dyno sheets.

E36 325: 210 WHP
2nd gen RX-7: 170 WHP

It's tough to estimate crank numbers because everyone uses a different figure for losses.

AB


------------------
Andy Bettencourt
06 ITS RX-7
FlatOut Motorsports
New England Region #188967

[Eagle7]

Originally posted by ITSRX7:
Just to clear up some numbers, these are from ACTUAL dyno sheets.

E36 325: 210 WHP
2nd gen RX-7: 170 WHP

E36 -> 13.6
RX-7 -> 15.8

------------------
Marty Doane
ITS RX7 #13
CenDiv WMR

[This message has been edited by Eagle7 (edited February 25, 2004).]

at 13.6 I would have said "E36 exceeds performace potential for ITS" if I was awake on the CRB.

[ITSRX7]

Originally posted by 7'sRracing:
at 13.6 I would have said "E36 exceeds performace potential for ITS" if I was awake on the CRB.

I think you have to take it for granted that they didn't know these motors were capable of this kind of power in IT trim. Actual dyno numbers aren't available at classing time. The 240Z makes 170 at the wheels like the RX-7...

AB

------------------
Andy Bettencourt
06 ITS RX-7
FlatOut Motorsports
New England Region #188967

what is touring car trim, isnt that just a blueprinted stock engine?, I have never seen T/C rules so I dont know but I cant believe nobody had a clue that it would be another CRX mistake, going back to working on my EP car before I get worked up.

[RSTPerformance]

Originally posted by gran racing:


Out of curosity, what type of times do you run at LRP? Not best ever, but typical times? (just curious how far off I am right now)



Mid to low 105's.... good enough for a run for first anyday.

[gran racing]

Thanks for the info.!

[ITSRX7]

Originally posted by 7'sRracing:
what is touring car trim, isnt that just a blueprinted stock engine?, I have never seen T/C rules so I dont know but I cant believe nobody had a clue that it would be another CRX mistake, going back to working on my EP car before I get worked up.

Who said anything about Touring Car rules?

AB

------------------
Andy Bettencourt
06 ITS RX-7
FlatOut Motorsports
New England Region #188967

[whenry]

Usually the person who makes the request for classification has a pretty good idea about the potential for the car including the availibility of parts(factory or aftermarket). Generally that info is not shared with the SCCA. So the question is how hard did SCCA tech look at the classification request? Would it surprise you to discover that some of the same people involved with CRX's are now involved with BMW's.
I hate to sound so much like a Rushie or such but been there; done that; and I have the T-shirt.

[m3ltw]

deleted for stupidity

[This message has been edited by m3ltw (edited February 27, 2004).]