So about these Pony Cars for ITR...

Knestis said:
I'm warming even more to the idea. Travis - Between my fiddling with it and yours, I've lost track: How did you get your New Multiplier, again...?

EDIT - The beauty of this kind of approach, Jeff is that it gets us "closer" - allows us to consider additional factors - without resorting to either (1) BS "what we know numbers" or (2) big chunk adders. Based on physical attributes of the car. It's something of an oversimplification I'll admit but I'm intrigued by the consideration that number of cylinders might play into the math. It's not a crazy idea to suggest that torque is influenced by that value.

K
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i have lots of thoughts on this, which i'll have to respond to later, the wife is needing attention.

but basically i used the ITA Integra as the baseline for a HP/liter/cylinder in stock trim, then calculated the percentage variance each of the other cars were from that baseline, and devide by 3 (totally arbitrary) to get the movement +/- 25%.

the first time through i didn't account for # of cylinders, and it worked well for all the 4cyl cars, but failed the 6cyl stuff. so i came up with another formula that included # of cylinders to give it a bigger adder than the 4cyl stuff.
 
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Knestis said:
I have no reason to distrust Blake's judgment but do we accept his numbers but not Bob's? We just can't reasonably decide.

K
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A large portion of Bob's numbers have been a leeeetle bit biased... any reason to think his dyno numbers wouldn't be also? :shrug:

Personally, this discussion seems like it's not much more than a lightly veiled attempt at getting several B-series cars' weights dropped on the premise that they'll never make enough power. Are the Del Sol and Civic Si VTEC cars mid-packers? Probably more so than the Integra/BMW/RX-7 but are they any worse off than a lightly developed TR8? All cars have different weaknesses but there's no guarantee of competitivness right? This just all sounds an awful lot like a fast-track to line item allowances for specific make/model/engines/etc.

Christian
 
Why? A 3.0 six cylinder BMW and Nissan inline and V6 makes about the same hp and torque as a 3.0 Porsche inline 4.

We are confusing no. of cylinders with displacement guys......

tnord said:
i have lots of thoughts on this, which i'll have to respond to later, the wife is needing attention.

but basically i used the ITA Integra as the baseline for a HP/liter/cylinder in stock trim, then calculated the percentage variance each of the other cars were from that baseline, and devide by 3 (totally arbitrary) to get the movement +/- 25%.

the first time through i didn't account for # of cylinders, and it worked well for all the 4cyl cars, but failed the 6cyl stuff. so i came up with another formula that included # of cylinders to give it a bigger adder than the 4cyl stuff.

there's lots of reasons my formula works....i think. but more later....probably after the wife has too many vodka's and passes out. :)
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Sorry - I contributed to the confusion. There are TWO issues here, the less important one being the number of cylinders. I'll set that aside for the time being to focus just on the potential of the "specific output adjuster."

I don't personally care any more or less about Bob's motivations or rationale, Christian, than I do anyone else's. To me NONE of that information is trustworthy enough on which to base rules decisions.

K
 
Actually, I agree that dyno numbers are a poor predictors which is why I looked at Hp/liter. The observation is as a consumer of Hp, when I went to buy more, the suppliers said "if its already 100 OEM Hp/Liter ,what do you want a miracle worker?

The honda is already a highly maximized, intake, emissions, and exhaust package. To ask a builder to give me 15% more hp, he has to find a way to flow 15% more gas (but the car already has a 4-2-1 header) or run at 1200 more rpm (readline is already 8200 rpm).. As he said, it aint happinen.

I have been to two different dynos, two tuners and got between 153 and 155 on 20 or more pulls. Its an ex pro engine in an ex pro car. Sure we could be missing something, but again its already nearly 100 hp per liter to the wheels. Where else can I look?
 
Are you:

1. Using Motec?

2. Have your exhaust extrude honed with merge collectors, and a custom header with pipe sizes by header.design or a similar program?

3. .040 over pistons?

4. Low resistance/tension rings?

5. Crank scraper? Windage tray?

6. Port match on the manifold to the head?

7. Allowed valve job?

8. .5 bump in compression?

9. You keep your oil and water at the temperatures necessary for best power?

10. You use the lightest oil your engine can stand?

11. How many hours have you spent on the dyno tuning fuel and ignition maps?

Bob Roth said:
Actually, I agree that dyno numbers are a poor predictors which is why I looked at Hp/liter. The observation is as a consumer of Hp, when I went to buy more, the suppliers said "if its already 100 OEM Hp/Liter ,what do you want a miracle worker?

The honda is already a highly maximized, intake, emissions, and exhaust package. To ask a builder to give me 15% more hp, he has to find a way to flow 15% more gas (but the car already has a 4-2-1 header) or run at 1200 more rpm (readline is already 8200 rpm).. As he said, it aint happinen.

I have been to two different dynos, two tuners and got between 153 and 155 on 20 or more pulls. Its an ex pro engine in an ex pro car. Sure we could be missing something, but again its already nearly 100 hp per liter to the wheels. Where else can I look?
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Jeff. I am not sure what in total has been done, other than this motor was second in Honda Challenge, and there was a lot of dyno, exhaust work and computer work by me. Plus the head and rings are fresh without a significant difference before or after. I don't see a glaring defect in performance or dyno curves, yet the ITAC's rules that says a 70 hp per liter 2.3, 9.8 compression ratio Prelude motor has the same development potential as a 100 hp per liter 10.2 compression ratio 1.6 Civic Si VTEC motor.

My thought is honda left a ton on the table for the base prelude, they put the cheap exhaust or intake systems on it and they tuned it for regular gas. Meanwhile on they knocked it out of the park with the civic Si VTEC with a real header, an unported version of the type r head, and tuned for premium gas. Yet for the rules, the ITAC says that each is a 160 hp motor. Funny thing though, the 2.3 prelude has the lap records.

Do you really think that the things you list are going to give a 100 hp per liter engine 120 hp per liter like a S2000 has in order for it to be competitive. Remember the Civic Si does not have the big primaries that the Type R has, nor the rev range. nor the valve springs. To make 20% more power, it has to flow 20% more air. So how is it that low tension rings are going to make it better than a type R? Just tell me who will get me 120 hp/liter at wheel and I will talk with him. I've done 6 well planned hours at the dyno with a Hondata 300 and the best header I could find and we checked multiple intake runner lengths. Using the guidance of an experienced B series tuner and other people I trust, they say aint going to happen if I stay within the rules. Tell me what to change to get 120hp per liter and I will do it.

Ps, I found the post claiming 220 whp for a ITS 2.5 alfa (88hp per liter). Look familiar? http://www.improvedtouring.com/forums/showthread.php?t=24972&highlight=gtv6
Why should I doubt 220 whp, its got 56% more displacement than my 150 hp motor? Perhaps he's stretching the truth, and only has 210 hp But with his 2680 weight while mine is 2550 (2350 dry plus driver) am I supposed to feel better?

Bottom line, Honda has done all the things you suggest for the VTEC motors, so at 100 hp/liter at stock, what am I supposed to do to get the 25% improvement assumed?


1. Using Motec? Hondata 300

2. Have your exhaust extrude honed with merge collectors, and a custom header with pipe sizes by header.design or a similar program? Done both pro header that came with car and Hytech Header, no siginificant peak difference though the hytech had a bit more midrange.

3. .040 over pistons? 020.

4. Low resistance/tension rings? Yes

5. Crank scraper? Windage tray? Yes

6. Port match on the manifold to the head? Not needed

7. Allowed valve job? - Not sure what is allowed - I have used the same guy used for 15 years, he used to do world challenge cars for PD cunningham. I don't think its a bad head job.

8. .5 bump in compression? Probably yes, not sure.

9. You keep your oil and water at the temperatures necessary for best power? Can't be sure but no indication of water temp problems from race data or dyno tuning.

10. You use the lightest oil your engine can stand? 0W 30 oil.

11. How many hours have you spent on the dyno tuning fuel and ignition maps? 6 well prepared hours setting maps and ignition- ran out of things to change. Air fuel ratio all well in control.
 
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Bob, go through that list and tell me if you know that those things have been done to your motor. If you don't know, then you don't really know what you have.

Each one of those individually is a small gain. Together, it is quite possible you could see that additional 10 or 20 horsepower you are not seeing at the moment.

I've seen the ITS Alfa ad you mentioned. Let's not draw comparisons based on a complete unknown. We have no idea what power that car makes, other than what is in an ad trying to sell it.

Look, I'll be honest. I've been where you think you are now -- totally maxed out. I've thought that MANY times. This is the best I can do....and then I start reading the rules or thinking more and there is always something more to do.

The funny thing is I don't totally disagree with your basic proposition that Honda and Acura motors might not get the 20 or 25% gain we expect. But given what you've told us, I'm not sure if your motor is actually a good example of that. I'm not trying to be rude, I'm just trying to convey the level of prep and effort it takes, for example, to get 200 crank hp out of a 2.4 liter Datsun 240z motor. It's LOTS of little things. LOTS of them.
 
I noted above what I believe the motor to have. On the other string on the Honda cars list, ITBlouis had a new sundial motor with 162hp 115 torque. Given variance of dynos and temps, there may be a horsepower or two between us but I don't think either of us will see 170hp any time soon . At this point I am pretty much done investing in a motor that is over 100 hp per liter and experienced Honda guys are saying its not worth it. Besides, its not going to make a difference against a 2.3 liter prelude. http://www.improvedtouring.com/forums/showthread.php?t=25399

If I wanted to win ITS at any cost, I't buy the the Lude. If I wanted to turn the same laps and win, I would build an ITA 1.8 non VTEC teg. I guess I am taking the hard route and trying to get the VTEC cars properly classed, or if it pleases ITAC, encourage them to create a B series VTEC class, because I would rather race my car than a Lude.

Bottom line, I believe an equalizer based upon hp/liter would be an improvement compared to the fixed assumption of improvements today.
 
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alright.....

i think bob's motives are extremely misplaced and dangerous. making allwances for a specific chassis, engine make, etc is a terrible idea i'd never support. but....if we can come up with something that treats every car in the ITCS equally, i might be kinda sorta mildly ok with it. maybe.

ITA Integra --> 140 factory rated hp / 1.8 factory displacement = 77.8hp/L. 77.8 / 4cyl = 19.44hp/L/cyl baseline. 25% * 1.25 * .85 = 149whp expected.

if someone else has an example of another car that hits closer to 25%, as i think this car actually makes a little bit more than this, please speak up.

using the 19.44hp/L/cyl as a baseline to determine how much above or below 25% a vehicle should be, we can try out some vehicles that are on the outer fringes of the current process to see how they end up.

BMW 325 --> 190hp / 2.5L = 76hp/L. 76 / 6cyl = 12.7hp/L/cyl. ((12.7 - 19.44) / 19.44) / 3 = -11.61% 25 - (-11.61) = 36.61% power adder. 190 * 1.3661 * .85 = 221whp.

Honda S2000 --> 240hp / 2L = 120hp/L. 120 / 4 = 30hp/L/cyl. ((30 - 19.44) / 19.44) / 3 = 18.11. 25 - 18.11 = 6.89%. 240 * 1.0689 * .85 = 218whp.

looks pretty good no?

one thing i REALLY like about using engine displacement and specific output is that it completely ends this whole torque debate, and yes Jeff, I think it fairly accounts for engine architecture as well. think of the basic characteristics you get from a motor achieving 2.0L of displacement from a small bore but long stroke, lots of torque down low, but not much peak power right? conversely, one with a very short stroke but large bore has lots of peak power but little on the bottom. how many times over the past year have people asked that the power adder use something simlar to this?

(HP + torque) / 2

what they're really asking is that both peak power and torque be given equal consideration. using displacement does that by saying that you can either have a torquey 2.0L motor or a peaky 2.0L, but not both. furthermore, we really don't care which set of charachteristcs (determined by engine architecture) your engine has, as we think each has advantages and drawbacks, neither one being better or worse than the other....just different.
 
PS - can someone send me a few examples of the V8 cars that might be classed in ITR? i want to see how they end up with my process to see if it works.
 
i spit out 284 for the 5L, 225hp Ford V8, and 290 for the 5L, 230hp GM V8. a little bit higher than what you had come up with in the proposal, but as far as how that translates into minimum weights....i bet it's an inconsequential amount.

i think i'm on to something here.
 
Travis ownz me on math!

But, Travis, if Kirk is right, and I think he is, how about plugging in 18% for the rear drivers??
 
18% loss for RWD puts the mustang at 274 and camaro at 280. 2.0 and 2.2 s2k at 210 and 220; 300ZX at 250.

sounds good right? except the 1.6 miata is at 121, and 1.8 at 133. that's low. do the other numbers look right? how much does the Datsun 240Z actually make? i think i'm low there as well.
 
tnord said:
i spit out 284 for the 5L, 225hp Ford V8, and 290 for the 5L, 230hp GM V8. a little bit higher than what you had come up with in the proposal, but as far as how that translates into minimum weights....i bet it's an inconsequential amount.

i think i'm on to something here.
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I think something is amiss.

1995 Ford Mustang GT; 215 hp stock, 5L displacement

215 / 5L = 43 hp/L. 43hp/L / 8 cylinders = 5.4 hp/L/cylinder.

5.4hp/L/cyl ((5.4 - 19.44) / 19.44) / 3 * 100 = -24.07%

25 - (-24.07) = 49.07, or a 49.07% gain.

215 * 1.49 * 0.85 = 272 REAR WHEEL HP

Maybe I made a mistake in there.

272 rear wheel hp is not obtainable in IT trim. If my arithmetic is correct the problem with this approach is that you've fixated on a 4 valve DOHC head (19.44 hp/L/cyl) design as your normalization factor and applying it to a 2 valve OHV engine. A 2 valve OHV engine has a lot of port and flow compromises due to pushrod pass through and valve location. A 2V OHV engine will never acheive the specific output of a 4 valve DOHC design, all things being relatively equal.

Anyhow, about the best that can be expected of the 1994/1995 Mustang GT 5L is around 235-250 rear wheel hp given the IT limitations and the inherit engine design.

I like the idea but we probably need a few different normalization constants depending on the engine design (4 valve DOHC, 2 valve SOHC, 2 valve OHV pushrod).
 
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What Ron said. Travis, I appreciate the effort but you are using a 4 valve, dual overhead cam motor as your "base" and then expecting other motors to have similar specific output. They don't.
 
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Hmmm....

I had to monkey with the class weight multipliers to get them so that they output current weight for some common, currently-competitive options in each class (we don't want wholesale changes in any kind of do-over we might implement) but there are some interesting comparisons falling out. I used .85 for FWD and .82 for RWD cars.

ITB

MkII Golf - 2260
MkIII Golf - 2479
Infamous Civic DX - 2012 (I DID include the +50 suspension adder for now)

ITA (no suspension adders, got bored)

EDIT - Deleted because I dorked them up. See later post...

ITR (distinction between FWD and RWD applied but no suspension adders used)

e36 325 - 2661
Integra GSR - 2143
205hp 'merican V8 - 3142
Type ARRR - 2318
S2000 2.0 - 2630

For discussion purposes only...

I'd be very interested to layer onto this a progressive FWD subtractor that assumes the kind of things Greg describes elsewhere here.

K
 
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