KaiB

Here's my point JR. (geez, I hope I don't sound Kibortian...).

It's a GT class and we can thus do damn near anything with our engines, regardless of it's type.

PCA has determined that we can derive more hp from a water cooled engine than an air cooled. I concur.

If each of us had $50K to spend, and each of us built an engine to the hilt, I can easily imagine that the water pumper would generate "X" more hp than the air cooled one...I believe 23% is a valid number.

I do wonder how true this is, perhaps others could chime in...let's say a well developed engine easily capable of lasting two entire seasons of t/t, practices and a full card of events...

winders

The fact that there "aren't any built M96 motors" is not really relevant. The simple fact is that you can get a lot more power out of the water cooled, four valves per cylinder, 3.6L M96 motor than you can any of the 3.6L air-cooled motors.

Are the multipliers perfect? Probably not. But I bet they are close.

It's funny how differently one sees this issue depending on which type of motor is in one's race car......

Scott

jrgordonsenior

The fact I have a horse in this race doesn't change the validity of my point. 500 lbs is too much of a handicap to overcome...

Chris M.

A simple power to weight classing system would make all of this irrelevant.

jrgordonsenior

Yep....

KaiB

+964 Yep, and take some of the ungodly money out, unless a guy wanted to spend it.

jakermc

Agreed, but I think the multiplier system in general is flawed. If you build your car out to maximize handling (suspension, big rubber, body work) you get forced into the GT class. With the multiplier system you are now also forced to make engine mods in order to be competitive.

That's why hp/wt is a much better system. It allows you to modify to the point your budget allows and still remain competitive. The GT class system forces a full build out, handling and engine, to run at the front.

NaroEscape

While I don't disagree, enforcement is the issue. Dyno sheets can be falsified, and having a dyno at the track is not cheap...who's going to pay for it?

Its easy to weigh a car, and fairly easy to determine displacement...If you can't enforce HP, what's the point?

Astroman

How does NASA pay for their dyno? How much does it cost to rent a dyno for 3 days?

ninjabones

I've said it before... I'd definitely support a reworking of the GT class structure to follow HP/weight (much like NASA GTS).

However, I won't hold my breath. It just makes far too much sense to be able to run the same car competitively in two different organizations, and to have rules that actually encourage parity and cost containment.

Veloce Raptor

jrgordonsenior

That's exactly what we did out west in the POC. We just completed our 2nd year of weight/WHP classes and they've really taken off. We've had many racers building cars for the specific classes and having Yokohama's generous contingency has really been helpful (same as in NASA). I race in both POC and NASA....

jrgordonsenior

Yes a dyno can be manipulated. Out here in Cali, a few of the tracks we run at with NASA(Sears, Thunderhill, and Buttonwillow) have Dynojets onsite and I've been dyno'd several times for compliance (always OK).

With POC we hire a portable dyno (Dyno Dynamics 4500) to come to 2 of our events each season in addition to running at the tracks mentioned above. We require everyone running our GT classes (weight/whp) to dyno on that particular machine and in the presence of a POC official. We set tire pressures (30 slicks, 35 DOT's), check for full throttle/pedal operation, and look for mutiple maps when we can like with Motec. When we run compliance dyno's on the Dynojets we first create a baseline with a few donor cars like 2010/2011 cups which all dyno about 415 rwhp. This allows us to compare the 2 different machines as Dynojets usually dyno a little higher).

NASA works out a deal with their Dynojets, something like $65 per car and they pay for the complaince dyno's. POC does the same at the 3 tracks w/Dynojets, but pay a set fee for the Dyno Dynamics dyno and then charge everyone a reasonable price for their 3 pulls. IIRC it's $50. We can dyno about 25 cars in a day which is about break even with costs. We expect to lose a little, but it's so important to have the our drivers have faith in the system and know we're dilgently policing the cars. We also also allow protest dyno's which may include confiscating a car and transporting it to our dyno for testing. The protestor would be required to post a $500 or more bond to cover all costs and would be reimbursed if the car was found to be out of class....

Ritter v4.0

Weight/hp is the weigh (sic) to go IMHO.

NASA are looking to obviate the need for dyno sheets (real or manipulated) by using data systems to extrapolate hp. Basically they'll put a Traqmate in select cars before a race, weigh them after and determine hp and from that data, and from it, Class.

I don't know anything about PCA multipliers, or much about what power potential lie in
an a/c 3.6 and an H20 (non-GT3) 3.6, but intuitively 500 lbs sounds like an extreme delta between the two. I'd be interested to know what real world numbers are achievable form both motors.

KaiB

I don't know anything about PCA multipliers, or much about what power potential lie in
an a/c 3.6 and an H20 (non-GT3) 3.6, but intuitively 500 lbs sounds like an extreme delta between the two. I'd be interested to know what real world numbers are achievable form both motors.

While I'd hate to get into the "my shop can do this for $x,xxx" game, it would be very interesting to toss a few numbers out; AC vs. WC and see where the rainbow falls.

It's well known that say $40K will get you a dyanamite 3.8 AC engine at 110hp/L and that this is just about the max build for a engine which will give dependable service over the course of two long seasons.