KaiB

My contention is that over a season or two, a 95-100 HP/L engine should last much longer than a 110 HP/L engine, if driven properly

This is exactly correct according to my engine builder and the goal we will shoot for, if not a bit more. We can easily build an almost bullet-proof 370hp engine which should keep us competetive - driver dependent - in GT4. Proper downshifts and a bit of short shifting are the key to engine longevity.

ninjabones

Good points about the relative advantages in aero/suspension, etc between a 993 and 996.. and how HP/Weight does not neutralize this advantage. I've competed against 996s, M3s, VWs, and older 911s in NASA GTS3, and certain platforms definitely offer some advantages (even the VW had a niche... great in the rain); However, none of these advantages even remotely compare to the advantage of 100+ horsepower (yes, the frontrunning GT4S cars have close to 100 more horespower than my car, which has a bone stock 3.6 993 engine).

Plain and simple, Hp/weight classing structure would create closer/tighter racing. As an example, at NASA Hyperfest this summer at Summit Point, the lap times of the top 8 GTS3 cars were less than 2 seconds apart. At the PCA races this summer at VIR and WGI in GT4S, the lap times of in-class competitors were separated by 10 or more seconds (and the front runners were more than 5 seconds faster than even the mid-pack cars). I wouldn't call this tight racing.

As in the current GT class structure, a HP/Weight structured series will still have certain cars that are faster (e.g. Josh Smith's M3 in NASA GTS3, national championship at Mid Ohio) and more gifted drivers (e.g. Josh Smith); however, even with an extremely developed, decade-newer M3, with better aero, detuned engine with flat torque curve, etc, Josh's best lap was still only 0.8 seconds faster than Bob Turgeon at Hyperfest/Summit Point , and Bob runs a 993 with horrible aero (in comparison wtih M3s and 996s), and he has a bone stock 993 3.6 engine with a peaky torque curve.

I'm willing to live with the fact that my 993 may not ever be as fast as a PDK Cayman or 996 at the same HP/Weight, but I am willing to accept this minor disadvantage, because I do believe it is surmountable, and I believe that the rules are simple and can be enforced. I can live with an 0.8 second disadvantage... I can't live with a 10 second per lap disadvantage.

So, this season, I've decided to focus more on the NASA racing. I will continue to race with PCA on occasion (Watkins Glen and Thunberbolt). Despite the comraderie and more track time, the actual racing experience in GT4S last season was a bit disappointing for me.

I hope that we can develop a HP/Weight racing structure in PCA for 2013. I would fully support (and even help organize) an effort to implement this.

KaiB

Nicely said Glen.

dan212

Let me throw a question from a different angle into the mix. How much is too much ballast?

Regearing my 996/X51 @ 31xx pounds. It was classed as GTB1. i can go into the top weight range for GT3 or add 200 pounds and be on the low end of GT4.

200 pounds seems like a lot of ballast to me. But if I don't, I'll be on the heavy side of 3

kurt M

Agree 100%. I built my track car when the old rules were in place. 2000# with a bone stock 993 motor, lots of rubber and a stiff tub. Fun as hell to drive on the track but not above the crease much less close to the pointy end in class.

NaroEscape

All,
As SoClose noted, policy and rules have evolved in PCA Club Racing through driver input. There is a very well defined procedure in place to affect changes, and beleive me, the voices of the majority are heard. So instead of spending 6+ pages here on Rennlist discussing the virtues of hp/wt vs displacement/wt, submit it during the open comment period. Each years rules changes come about from driver input, not just random discussions.

And the more people that submit similar ideas, the more likely they are to be accepted as rules.

Be complete. Don't just say 'we need GT to be hp/wt'. Give ideas on HOW to make that happen, how to enforce it, basically how you would write the rule given the chance. If enough people submit, maybe we can make a change.

jrgordonsenior

I'd like to see you lighten your car and stay in 3 rather than carry all that ballast. I know you can't get it down to the bottom of 3 (2675), but you could drop 100-125 without breaking the bank with doors, hood, and polycarbonite glass. Ritter 3.4 just did that with his 996....

Side bar: Another example of how screwy the GT class multiplier is, the X51 with 345 flywheel HP uses the same index as my 3.4 with 295 flywheel HP....

jrgordonsenior

+ 100000.....

I completely agree that 996's have an advantage over equal weight/WHP air cooled 993's, 964's, 911's, etc. So how do you equalize that in a weight/whp series or do you ignore it as NASA"s GTS series does?

My suggestion is to look at NASA's ST (super touring) classes which are also weight/whp but with penalties/ bonuses for things like tire types and sizing, weight, and a few others listed below. They also assign a penalty for factory built race cars like a GT3 cup (+.4). I think something along those lines could be explored with respect to the 996's, 993's, etc.

Here's the ST rules if anyone wants to scroll thru...
http://www.nasaproracing.com/rules/Super-Touring.pdf

SoClose

+ 1

KaiB

Nah, JR...I would propose a simple GTS type ratio.

One of the attractions of GT is the "no holds barred" system. If I can't get my suspension close enough that driving won't get me close to those with more modern platforms, well so be it. Why complicate a proven system.

I like simple personally.

flatsics

That is also the big problem with the GTS rules.
The main reason that GTS racing is somewhat close--- the lack of rules in GTS is not presently being utilized to its full potential.

Most GTS cars are stock based engines with a wing and a splitter and a decent suspension that is based on stock components.

There is basically two rules in GTS
Weight/HP
Engine must be same manufacturer as the chassis.

Do you really think that the current GTS cars are taking full advantage of the rules?

Here are few ideas:
Sequential trans
Active Aero
Moving suspension pick up points
Utilizing true racing suspension designs-not MacPherson strut.
Race ABS
Race traction control
Engines built and designed just for Weight/Hp rules.
Carbon brakes

You can basically build a psuedo-DTM car that meets GTS rules for Weight/HP

You say, "that's stupid--that will never happen"

Change the PCA rules to "no rules" and see what happens.
Hell, we have Spec Boxsters with air jacks.

ninjabones

Sure Doug... as the class evolves, there will be people who take advantage of the possible upgrades, and I have no problem with that (with only a few exceptions). There are a lot of highly developed GTS3 cars in NASA (PDK Caymans, M3s with motorsport ABS upgrades, plenty of 993 guys move their front suspension pick-up points to RSR spec). However, the racing is still tight and none of these developments would even come close to overcoming a 100 HP deficit. As a caveat, I would probably condone a ban on active aero for safety reasons, and in my personal opinion, I would bump sequential tranny cars to the next higher class (much the same way that tube-frame purpose-built race cars are bumped to the next higher class... mostly for cost containment reasons).

winders

Exactly. The PRC out here in Northern California has a wonderful class called GTL (GT Limited). Basically, the class uses PCA GT rules with certain limitations. Specifically:

----------------------------------------------------------------------------------------
Chassis: Must be a Porsche 911 or 914 chassis up to 1995. 993 and later chassis types are prohibited.

Weight: 2350 lbs minimum with driver.

Engine Type and Size: Porsche, 2 valves per cylinder, Normally Aspirated, Air-cooled, and 3.6L or less

Engine Management System: Free

Intake Manifold: Must be from a 1984 – 1995 911 and stock with some mods allowed

Headers: Maximum primary header tube size allowed is 1.625” O.D.

Mufflers: Free as long as the engine noise meets the restrictions of the various tracks

Tires: Goodyear Bias-ply Slicks. Front 23.5 x 10.5 x 16 or 23.5 x 11.5 x 16. Rear 25 x 13 x 16 (R430 compound)

Transmission: Factory unit and cannot be a "dog box".

Suspension: Front must use MacPherson struts and Rear must use factory trailing arms. Otherwise free.
----------------------------------------------------------------------------------------

This class offers a huge amount of freedom yet has enough restrictions in place to keep costs somewhat in check. Nobody will be grafting 993 suspensions on to the cars. An 1800 lbs car is not needed. Sequential or "dog box" transmissions won't be used. Engines will last for a long time because there is no point in spinning them past 6800 RPM.

I loved the concept of this class and built a car just for it.

Scott

NaroEscape

But isn't that basically what PCA GT rules are:

- Weight/Displacement factored
- Engine & Chassis must be Porsche

Not sure how changing Weight/Displacement to Weight/hp equates to "no rules" or is much different that what we have now.

Astroman