Oddjob

Have you guys seen this?


944 Turbos:

There is a continuing concern about the effectiveness of the 20+ year old boost control system. It is necessary to limit boost in these cars to a peak or spike pressure, to a steady state pressure, and to the length of time it takes a peak to decay to the steady state, but it appears that by now the original systems don't allow the original maximums (which can be measured with our data system) all to be met. As a result, 951s are being converted to normally aspirated motors, at least in SP3. Devising more modern control systems involves considerable expertise, and cooperation with aftermarket manufacturers. Such systems would have to keep these turbocharged engines within their original capacities in order to be fair to other cars in their classes. The Club Race National Staff can't devise such systems on its own. Two likely approaches which would allow boost controlling to involve aftermarket parts (certainly not cockpit adjustable), and perhaps sealable at the track if adjustable, are:

a) Specify not to exceed spike, decay, and steady state parameters, probably altitude corrected. If this is done, what should they be? How should the early turbo be differentiated from the S model?

b) Adopt an altitude corrected system like IMSA uses for turbocharged cars in the Continental Tire Sportscar Challenge for Grand Touring Daytona:
A single maximum boost pressure.
No spike can exceed 125% of the maximum.
The maximum can be up to 7% higher for no more than 7% of the time for that lap.
The total time over 7% may not exceed 3% for that lap.
No single event over the maximum boost may exceed two seconds.

You can find the formula for altitude correction on the IMSA website.

What should the specified "maximum" boost be, and how should these differ between S and non-S? Should any of the percentages be different, and if so, what should they be?

It would be helpful if any aftermarket systems had some built-in flexibility, so one or more parameters could be changed if experience showed that was needed.

Those interested in this approach are requested to e-mail xxxxxxx. We will put all those interested (and those with the special knowledge needed who may agree to help) in touch with each other, so a working group can be formed to see if something feasible can be done. The 951 is a terrific Porsche model, and its exit from Club Racing would be a shame. But active involvement of racers, shops, and aftermarket parts manufacturers will be needed so a proposal can be put out for racer comment.

User 41221

Droops83

I don't have any thoughts or answers about the above issue, but this is why POC has largely moved to GT classes based on power-to-weight ratio----pretty much everything else is open (a stock-ish 951 would be in GT5). Policing this stuff must get exhausting!

V2Rocket

isn't that why LR offers the "club gate" WG?

951and944S

I doubt seriously a change here is going to see an improvement in comparable performance of the 944T and 944TS against the other SP3 entrants.

To warrant a change, participants should have to show race condition data that shows that they are experiencing less than the allowable 12.5 psi boost.

Maybe they have, or it has already been recorded by the CR equipment, but we have been fitted with the data device and it seems to be based on g-force acceleration only. (?), could be that there is boost measuring capacity but why wouldn't the rule book state that "for turbo cars", an accessible port must be available for the purpose of rules compliance testing like they did with the 4-way data port...?

I like the turbo cars, and surely want to see them populating the SP3 class. That said, we don't (and won't ) field one but personally, I think it's more related to the power delivery + adapted driving style that is the reason they suffer vs the S2. and 968.

Exhaust for the 944T is already open, including header from the exhaust port, X-over pipe, all the way to turbo housing.
Lindsey waste gate is already allowed.
Just keep the KLR chip, and issue A PCA, non tamper sealed boost enhancer set at 12.5 psi.
Anybody having trouble making less than max legal boost with mods that are already allowable have other problems.

Just lighten the car another 50 lbs and see where that goes.

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951and944S

Always disparity in a class with such varied engine platforms.

Next year, the S2 guys will want a change.

What they should do once a year is have 1 single agreed driver make 3 laps in each variant to get an overall lap average for each, 944S, S2, 968, 944T and 944TS.

All representative race cars should be as equipped by the factory, i.e., stock bodied, stock rear wing, and since all cars in this class are late offset, a control tire.

Anything outside that is owner/builder discretion and should not be taken into the equation.

You have some cars with giant upright rear wings, frontal canards, etc., etc. and wonder why they get blasted at a track with two 3000+ ft straights, competing against a stock bodied 968 with factory rear wing and then they start squealing about lack of power.

Well, the stock car is suffering in the turns because of lack of downforce.

Watch just a couple minutes of this race start.
Car with camera is my son Eon, first time ever in this car, stock body 968 in SP3.
Directly behind at the green is a 944T that I'm pretty certain had a non-allowed wastegate at the time because next event, he reported to me personally that he was DQ'd from SP3 and moved to GT.
The other example is a wide body 968 with frontal and rear wing drag.
The stock 968 (which I guarantee 100% has a stock legal engine) walks away from both cars but struggles in the turns.
It's owner preference, both are legal formats.


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951and944S

Vid may not load from start so make sure to set to 0.00.
After seeing start example for 1-2 minutes, FFd to 11.30 and watch what happens.

And at 18:15, that's our own Max Energy in his 2.7L NA GT 944....

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Oddjob

What... your user name is a misnomer?

951and944S

Lol, yes, was into the turbo cars back around 01-05 but have been consistent with the S all the way through.

Love the cars, just wouldn't track one competitively....., I'm just the wrench these days mostly and they are too complicated, compact and get way hotter by comparison. I just practically gave away the last item that tied me to a 944T race car project to friend and RL'er West Dillard, my last 3.0 liter block.

Ironically, I'm known all over the web as Turbo-T for almost 20 years but when I registered here in 01, Turbo Tim was here so I didn't challenge him for it.

Close friend in south Spain runs a large following Twitch video game streaming channel and I'm even known there as 'Turbotito'.

Crazy.....and thanks Jim, now I guess I'll have to get another turbo car since you brought it to my attention.

Been looking at the Merc C250 1.8T coupe.

Hah hah...

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Oddjob

I've been tracking 951s since '93 and club racing them since '03. I did start club racing in a stock class 944S, but moved over to a turbo after a few years.

Based on the limited replies here, seems like very few are still racing in PCA (?).

Oddjob

In the video posted above from NOLA, were more Eurosport cars at the event, in addition to Hiffman? We get a few of their SP3 cars at my home track events each year (BIR). Hiffman and Dunne were up here last wknd.

951and944S

To tell you the truth, racing in general doesn't get much attention in this forum, so I wouldn't weigh much on number of replies.
That said, in personal experience, even though we run across a few at a big race like Sebring, the main ones I know of are GT cars and wouldn't be affected.

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951and944S

This particular vid from 2018, no, just Dennis this time but they were all there in 2017.
Following race the whole crew were at Barber but I have no vid because my son was in SP2 car for that one.

These are the droids you're looking for (top 3 SP3 cars were the only ones to outqualy my son Eon in 2016)


Plan was to exchange suspension for new dampers on this yellow 968 and make it to Daytona in October where a lot of these same guys attend but not 100% sure as of now because we have another tub for this drivetrain about to go to a metal stripping process to build it up from scratch due to some shady mods made by previous owner for vintage racing.

Real mark in SP3 is Poeltl though...

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951and944S

BTW Jim, didn't realize this was this particular vid, but watch rear view mirror....

Those were the rest of the SP1,2 and 3 cars (son is in his SP2), in this 1st sprint, theres a good race going on back there with current (I think) 2018 SP1 points leader Mitch Butaud in the salmon "Pink Pig" car.
Our car has only front coilover over the SP1 cars and 16" wheel, no header, chip, etc.
We are friends with all those guys behind, Chris Blazer in the baby blue car grids right behind for Sprint 2 and does his best to hang onto Eon, but in 2-3 laps he's pretty much out of sight in the mirror.
If you have time, past the 6.00, SP2 car catch and pass a string of D, E and Boxster.
You would like this track.....flat but good sighting and the esses are made for a 944.


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951and944S

For those who wait out that 1st vid in post 13, d@mned if it aint the forum's own Max Energy again at 12.00 just as it starts to drizzle....

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