Results, rumours and inuendo...

[Beran]

k,
My motor was completed just in time to get it in the car and in the trailer and on the road to Road Atlanta. The planned dyno time never happened. I think we will try to get some dyno time in this winter. When we do then I will share. I ran all season with a good head but a 150K block/lower end etc. Shine did do a ton of development and research for another customer for the same motor so there has been lots of development put into the motor and car.
IMHO the 924 is one of the killer cars for ITB. Once hooked up it will be hard to beat. Maybe it's a little heavy now but a couple letters and it might get adjusted.
I am not too familiar with the Prelude but doesn't it have a lower and upper control arm? If it does then it is a much better setup then what the VW has.
The three VW's up front were very close in power. Derick and I were very very close. if he was behind me he could easily draft by me on the back straight without me being able to do anything. Honestly the three of us could have come into 10a every lap three wide if we wanted to. Since the Golf is such a brick it really gave the guy in back a huge advantage over the person in front.
What an awesome track - i loved it.
I look forward to going back.
Beran

[ScotMac]

TTIWWODP = This thread is worthless without dyno plots.

Post 'em up there, guys! I showed you mine, so you should show me yours.
I don't know my Hondas all that well but is it the same basic beast as is on the front of the Integras? Oh, Captain Panties - your opinion?

K
[/b]

No problem, but it is not a pretty sight, as compared to that golf one. Just a sec, i gotta find the software to read it again...

[Conover]

sorry, but i don't understand what you mean about risking metallurgical integrity to add camber to a honda.

do you consider the 1st gen 84-87 crx's not to be a strut car? or are you referring to 88-91 crx's?
[/b]

I'm referring to the guys that put their uprights on the press and bend them a little to get that extra degree of static camber. I'm mean in reality it's probably not that big of a deal, and sure, why not, right, but in my opinion most of those cars don't need it. I can't tell you the difference between 87 and 88 on a CRX, give me a couple of weeks and I'll be on the same page with you. . .

[Andy Bettencourt]

I'm referring to the guys that put their uprights on the press and bend them a little to get that extra degree of static camber. I'm mean in reality it's probably not that big of a deal, and sure, why not, right, but in my opinion most of those cars don't need it. I can't tell you the difference between 87 and 88 on a CRX, give me a couple of weeks and I'll be on the same page with you. . . [/b]

Here's your answer - NIGHT AND DAY!

The 86-87 cars are Torsion bar fronts and the 88-91 is double wishbones. The TB fronts I would not consider a strut based set-up obviously.

[Bill Miller]

Don't forget you have 20% more displacement to work with....
[/b]

What's that supposed to mean Andy? Are you saying that the process assumes greater gains from an IT tune on motors w/ larger displacement?

[Andy Bettencourt]

What's that supposed to mean Andy? Are you saying that the process assumes greater gains from an IT tune on motors w/ larger displacement? [/b]

It is most certainly a consideration on the subjective side of things. Not part of the 'formula side, but always a consideration. (Not speaking specifically to the Fiero and it's weight, just pointing out that apples that look like apples may not be apples) IIRC, the ID 2.5 Fiero was one car that was 'left alone' in the great correction due to the lack of knowledge base, participatory drivers and large displacement (potential for atypical torque numbers in IT.

[ScotMac]

Here ya go...oh, in terms of the engine, as Andy brought up, the displacement is not AT ALL taken advantage of in this engine. ie, it doesn't breath well at all. Focussing on that, my car has hooker super comp header and the head has been port matched (as much as allowed by the rules) to match that header and the intake manifold. I believe it is an 020 overbore, and the head was leveled a bit (dynojet based):

It is most certainly a consideration on the subjective side of things. Not part of the 'formula side, but always a consideration. (Not speaking specifically to the Fiero and it's weight, just pointing out that apples that look like apples may not be apples) IIRC, the ID 2.5 Fiero was one car that was 'left alone' in the great correction due to the lack of knowledge base, participatory drivers and large displacement (potential for atypical torque numbers in IT.
[/b]

Thanks Andy. That answers a question i have been trying to get an answer to and confirms my suspicions.

As far as i have seen, the Fiero HP numbers are well off the other ITB cars. It is true that the torque numbers are better, but only to the extend of allowing the torque to be on a par w/ the rest of the cars, not higher.

[shwah]

That torque beyond on par with an A2 VW, but we weigh less, so it should wash out.

I just keep wondering if our local Fiero was pulling my leg with the 190lb-ft comment...

[ScotMac]

That torque beyond on par with an A2 VW, but we weigh less, so it should wash out.
[/b]

No idea how much torque on the A2 VW, but it is even lighter than the mk III, right? 2280? So, it's torque is less than 120ft-lbs, rear wheel on dynojet in IT trim?

Figuring in weight, the fiero is about the same torque as Kirk's mk III golf, tho the golf is still better. Golf is 18.36lbs/ft-lb, and Fiero is 18.75lbs/ft-lb. It is much worse for HP. Golf is 21.36lbs/hp and Fiero is 27.13/lbs/hp.

But, as i said, this is just specific individual examples...not the best thing to base classing on. As i showed before, the stock numbers are worse for torque, but a bit better for HP, though still show a very large disparity (15.4lbs/ft-lb vs 16.5lbs/ft-lb and 16.3lbs/hp vs 20.8lbs/hp, golf vs fiero, respectively).

I just keep wondering if our local Fiero was pulling my leg with the 190lb-ft comment...
[/b]

That's what i said!!! I think that would be difficult for the v-6 (ITA)...it isn't imaginable for the 4 banger.

[shwah]

My motor is a full build.
.40 over
balanced internals
machine work by AMT Racing Engines
built by the same builder of Chuck Mathis podium GP motor (Chuck)
fresh head (edit - IT legal porting, factory valve job, new guides/seals/lifters, resurfaced)
10.47:1 compression ratio
Techtonics header
fueling is very right
underdrive pullys

The result on a Dynapac was 109hp 105ft-lb once we got her all together.

We altered timing and fuel on the dyno as expected, and also tried different intake tubes from the fuel distributor to the throttle body - whoda thunk that the stock pipe would perform best...

[Knestis]

I'm fairly ignorant on the Prelude engine...[/b]

I was thinking you might have an opinion about A-arm vs. strut suspension after driving an Integra. Of course it might not apply if the Prelude isn't A-arms, although I think it is...?

The result on a Dynapac was 109hp 105ft-lb once we got her all together.[/b]

Thanks for those numbers, Chris. It's a very interesting comparison of the 1.8 and ABA engines. I'm pretty confident that the differences between those two options are truly within "different horses for different courses."

Something that i may have missed - where would the 4-cyl Fiero be weight-wise, just looking at the stock quoted power/torque figures and other typical adjusters? I did know that it hadn't been through the Great Adjustment.

K

[shwah]

No idea how much torque on the A2 VW, but it is even lighter than the mk III, right? 2280? So, it's torque is less than 120ft-lbs, real wheel on dynojet in IT trim?
[/b]

Realizing that my info is just one data point, and that not everyone here knows the VW stuff like Kirk and I, here are the salient differences between the A3 and A2 Golf:
A3 has 2 liter vs. A2 1.8 liter - much of this is longer stroke, thus my comment about expected torque gain
A3 has crossflow 8v head vs. A2 counterflow 8v head
A3 has an ever so slightly less desireable cam profile
A3 chassis is pretty close to a 11/10ths scale version of the A2
both cars can run rear drum or disk - and yes some think drums are better (I started this way, but changed to disks for ease of maintenance, and lower rotational inertia despite higher assembly weight).
A3 has 10.1" vented front disks vs A2 9.4" vented front disks
EDIT - A3 can run 14x6 or 15x6 wheels vs A2 13,14 or 15x6 options
A3 has a more advanced 'Motronic' engine management system, A2 can run Bosch CIS-E continuous flow system or VW Digifant electronic system (I run CIS-E, the A2 that ran at the front of the ARRC was Digi)
A3 is speced at 70# higher weight.

They are similar on the macro scale, but are different cars in the details, and have different strengths. I do think the A3 is the car to start with between the two if you want to go as fast as possible, but I am also a bit bull-headed and think I can build an A2 that can beat them - and hope to do that. Success or failure will both provide some fun times, but the former would be much sweeter.

You won't find me complaining often (hopefully at all, and if I come across that way it is not intended) about the competitiveness of my car of choice, as I beleive it is a 'prototypical' ITB car. I also appreciate that it has had a long run as one of the the front runners in ITB in general. A2 Golf owners are the last ones in the world that have a reason to complain about classing IMO.

[ScotMac]

My motor is a full build.
.40 over
balanced internals
machine work by AMT Racing Engines
built by the same builder of Chuck Mathis podium GP motor (Chuck)
fresh head (edit - IT legal porting, factory valve job, new guides/seals/lifters, resurfaced)
10.47:1 compression ratio
Techtonics header
fueling is very right
underdrive pullys

The result on a Dynapac was 109hp 105ft-lb once we got her all together.

We altered timing and fuel on the dyno as expected, and also tried different intake tubes from the fuel distributor to the throttle body - whoda thunk that the stock pipe would perform best...
[/b]

Thanks for the numbers. Interesting. I don't have a lot of knowledge of dynapac, but i hear quotes that it is lower than dynojet. Dynojet numbers probably wouldn't put you over 120ft-lbs, but might it be close?

Something that i may have missed - where would the 4-cyl Fiero be weight-wise, just looking at the stock quoted power/torque figures and other typical adjusters? I did know that it hadn't been through the Great Adjustment.
[/b]

That's is exactly what i would like to know. Andy, can you help us?

I can guess, based on those A3 Golf numbers, though...

If we are really using a 16lbs/hp mulitplier (like the Golf), let's say we add a pound or 2 for mid-engine and aero, and torque (though torque is same A3 Golf). That puts the fiero at 2200lbs for ~18lbs/hp. That would be a little low for torque, though : 14.3lbs/ft-lb. So, maybe around 2300lbs? 2300lbs puts the Fiero at 18.8lbs/hp and 15lbs/ft-lb, as compared to the A3 Golf at 16.3lbs/hp and 15.4lbs/ft-lb.

The car is light, so i believe it could probably get to that weight. Even stock it was 2590-2790lbs.

[tom91ita]

okay, with regards to the honda and camber, here is the 88-91 civic/crx front knuckle:

https://www.hondapartsdeals.com/honda_parts...component=B++27

here is the first gen (84-87) front knuckle that the shock goes into and then up to the upper shock mount and typically camber plates to get camber adjustment:

https://www.hondapartsdeals.com/honda_parts...component=B++27

[shwah]

Thanks for the numbers. Interesting. I don't have a lot of knowledge of dynapac, but i hear quotes that it is lower than dynojet. Dynojet numbers probably wouldn't put you over 120ft-lbs, but might it be close?
That's is exactly what i would like to know. Andy, can you help us?

I can guess, based on those A3 Golf numbers, though...

If we are really using a 16lbs/hp mulitplier (like the Golf), let's say we add a pound or 2 for mid-engine and aero, and torque (though torque is same A3 Golf). That puts the fiero at 2200lbs for ~18lbs/hp. That would be a little low for torque, though : 14.3lbs/ft-lb. So, maybe around 2300lbs? 2300lbs puts the Fiero at 18.75lbs/hp and 15lbs/ft-lb, as compared to the A3 Golf at 16.8lbs/hp and 15.4lbs/ft-lb.

The car is light, so i believe it could probably get to that weight. Even stock it was 2590-2790lbs.
[/b]

Scott - You will kill the class with that kind of torque and less weight (or the same weight) than an A2 Golf. I do want to see where the thing falls in the process, but something is going awry in your logic there. The 2.5 liters of displacement does make a difference - even if flow is not ideal for the motor. This is evident in the torque performance of the motor, which is what actually moves our cars down the track. My understanding is that the Duke is typically not a rever due to mechanical challenges (weak crank) as much, or moreso than top end breathing. Yet it makes great low end torque because, well it has almost 50% more displacement than my motor.

The one thing we need to remind ourselves, is that it is all well and good to share our dyno data, and talk about it, but these graphs are in no way comparable to each other, other than on very basic terms - even if all generated on the same brand of machine. There are too many variables at play that impact the data collected on a dyno to consider a factor to compare data from one type to another, or even to compare my numbers to Kirks on an apples to apples basis. I have also not found the same correlation that Andy mentioned about dyna-pak reading lower than other dynos, I have found that to be the case with dyno dynamics machines though.

My previous motor was a stock 60k mile engine, with a header and correct fueling/timing. It returned 96hp and 103ft-lb on the same dyno, this at least removes one of the other variables, and is the best way to use a dyno - as a before and after measurement. It does tell me that we did not get the oft quoted 25% improvement. Yes we had done some easy mods before, but the numbers for my used motor were not that far off the numbers for a healthy stock motor on that dyno.

The bottom line is that there are physical characteristics of engines that impact their performance and performance potential, just as there are for a chassis, or braking system. The process, from my understanding, tries to take some of this into account to get us in the same ballpark and sends us racing to sort the rest out. If we want to use dyno runs to class our cars, we should look at what classes NASA has to offer, because that is not an IT consistent approach IMO.

Like I said, I would like to see where the process puts your car - if it was not reviewed in the Great Adjustment, but IMO if it comes out as close to the A2 Golf as the numbers you just quoted, it will be off the mark, and that car will dominate the class on most tracks.

[JeffYoung]

Not an ITB guy, but will weigh in here with one bit of anecdotal evidence only. For the Fiero guy, I'm a lot like you, but in S: class leading torque (or close to it) but a bit down on hp. 195 ft. lbs, 160 whp last time I checked.

What you give up at the very end of the long straights you can make up (and more at shorter tracks) getting off the corner and getting up the hills.

A torque advantage can be as significant if not more significant than a corresponding hp advantage in my experience. After last year, I'm pretty confident that if I can solve my rear end "hook up" issues, the car is a top 3 car in the SEDiv (top 5 or so right now).

Don't dismiss the torque advantage, and learn how to use it. It's not all about that last 1/8 of a mile on the straights.

[Knestis]

Interesting asides aside, we've got a blurb and great Tom Hoppe pics up on the site at...

http://www.it2.evaluand.com/gti/arrc07.php



K

[ScotMac]

Scott - You will kill the class with that kind of torque and less weight (or the same weight) than an A2 Golf. I do want to see where the thing falls in the process, but something is going awry in your logic there. The 2.5 liters of displacement does make a difference - even if flow is not ideal for the motor. This is evident in the torque performance of the motor, which is what actually moves our cars down the track. My understanding is that the Duke is typically not a rever due to mechanical challenges (weak crank) as much, or moreso than top end breathing. Yet it makes great low end torque because, well it has almost 50% more displacement than my motor.
[/b]

What, is there a new VW i don't know about, at 1.5 litre? If not, then come on Chris, the statements here have been close to accurate...let's keep it that way. .7 is 39% of 1.8, not 50%. Yes, my displacement is greater than yours, but how relevant is that if the engine doesn't use that displacment to produce greater HP and Torque?

Yes, the engine does have mechanical challenges (tho not necessarily the crank). But the top-end breathing was definitely not designed to handle the revs, which can easily be seen on my HP chart.

The one thing we need to remind ourselves, is that it is all well and good to share our dyno data, and talk about it, but these graphs are in no way comparable to each other, other than on very basic terms - even if all generated on the same brand of machine. There are too many variables at play that impact the data collected on a dyno to consider a factor to compare data from one type to another, or even to compare my numbers to Kirks on an apples to apples basis. I have also not found the same correlation that Andy mentioned about dyna-pak reading lower than other dynos, I have found that to be the case with dyno dynamics machines though.
[/b]

That is what i have been saying ALL along. That specific examples mean little. However, the process has to base it's number on SOMETHING, and i believe it is the more generic stock numbers, along w/ other factors. And the stock numbers actually agree pretty well w/ the specific examples here.

My previous motor was a stock 60k mile engine, with a header and correct fueling/timing. It returned 96hp and 103ft-lb on the same dyno, this at least removes one of the other variables, and is the best way to use a dyno - as a before and after measurement. It does tell me that we did not get the oft quoted 25% improvement. Yes we had done some easy mods before, but the numbers for my used motor were not that far off the numbers for a healthy stock motor on that dyno.
[/b]

Andy can correct me if i'm wrong, but i do not beleive the 25% number AT ALL means that each car will acheive that. My car obviously has not yet. It was simply chosen as a method of allowing consistency in the initial classing of cars via the process.

The bottom line is that there are physical characteristics of engines that impact their performance and performance potential, just as there are for a chassis, or braking system. The process, from my understanding, tries to take some of this into account to get us in the same ballpark and sends us racing to sort the rest out. If we want to use dyno runs to class our cars, we should look at what classes NASA has to offer, because that is not an IT consistent approach IMO.
[/b]

I don't think that anyone here is proposing that we use dyno runs to class our cars. That is a whole different topic.

IMO if it comes out as close to the A2 Golf as the numbers you just quoted, it will be off the mark, and that car will dominate the class on most tracks.
[/b]

I disagree that it will dominate any MORE than the MkIII Golf. The numbers i chose put it OVER 2lbs/hp worse than the MkIII Golf, at about the SAME torque (using *stock* hp and torque).

Like I said, I would like to see where the process puts your car - if it was not reviewed in the Great Adjustment.
[/b]

That's all i am asking, for it to be reviewed via the process.

[shwah]

What, is there a new VW i don't know about, at 1.5 litre? If not, then come on Chris, the statements here have been close to accurate...let's keep it that way. .7 is 39% of 1.8, not 50%. Yes, my displacement is greater than yours, but how relevant is that if the engine doesn't use that displacment to produce greater HP and Torque?

Yes, the engine does have mechanical challenges (tho not necessarily the crank). But the top-end breathing was definitely not designed to handle the revs, which can easily be seen on my HP chart.[/b]

OK. So your car has a much larger engine (40% or 50% are both big differentials), and makes more torque, despite not breathing well up top (if we were taking the dynos literally I could argue that your car makes more ft-lb than mine for 3/4 of the rev range). Maybe I'm reading this wrong, but it comes across that you think your car is disadvantaged because it does not make high rpm hp and should recieve some 'consideration' in the process. Maybe we see what the process says before jumping to that conclusion.

My opionion is that a 2200 or 2300lb Fiero would be an easy car to win in at a 7 or 8/10ths build.

As an aside, yes there were two 1.5 liter vw motors back in the early Rabbit/Scirocco days .

That is what i have been saying ALL along. That specific examples mean little. However, the process has to base it's number on SOMETHING, and i believe it is the more generic stock numbers, along w/ other factors. And the stock numbers actually agree pretty well w/ the specific examples here.[/b]

I agree that the specific examples are illustrative only, not true data for classing purposes.

Andy can correct me if i'm wrong, but i do not beleive the 25% number AT ALL means that each car will acheive that. My car obviously has not yet. It was simply chosen as a method of allowing consistency in the initial classing of cars via the process.[/b]

I am not in any way complaining about the gains we achieved. My comment about gains realized are germane to the conversation, because you began lobbying in post 109 that your car does not acheive typical gains, due to airflow restrictions. Lots of cars fall in that boat. Not to mention that you appear to have top shelf torque despite that handicap, despite potentially not being a full build motor (CR?, balanced?, fueling?, .40?). We all give something up in some places and gain something in others.

I don't think that anyone here is proposing that we use dyno runs to class our cars. That is a whole different topic.[/b]

I agree.

I disagree that it will dominate any MORE than the MkIII Golf. The numbers i chose put it OVER 2lbs/hp worse than the MkIII Golf, at about the SAME torque (using *stock* hp and torque).[/b]

One event does not define dominance, and one dyno plot does not define performance of a single model in this class.

That's all i am asking, for it to be reviewed via the process.[/b]

And this is a valid request.

Asking for a car to be reviewed is fine, but trying to couple that to annointing another car that fits the class well as an overdog, while lobbying that your particular car cannot acheive the goals needed to be competitive in the process - before we even know where it will fall out is more than that.

Maybe it's just the poor communication method that is internet posting, and I am totally misunderstanding you.

[ScotMac]

Chris, i agree, the MkIII-Golf and Fiero issue are different issues. It was just so glaringly obvious that the Fiero needed to be evaluated when i saw the numbers for the Golf as compared to its weight. Also, since we conveniently had numbers for Golf, it was used as way of deriving numbers for the Fiero, since it hasn't been evaluated.

I am glad we mostly agree. The only real disagreement being my numbers. Note, those numbers are AGAIN simply derived directly from the STOCK numbers for the Golf HP and Torque. Obvoiusly they don't take into account other factors (aero, brake, suspension, ...), but they are accurate for HP and Torque. In fact, i EVEN gave the Golf a *better* power-to-weight ratio by *2* lbs/hp, to allow for any slop in the other "process" parameters.

Anyway, rather than arguing about it, lets just wait and see how it plays out (i have already sent the letter).