TurboS

[QUOTE=TB993tt;11593529]You got a 7GT2, that is awesome

I would go with GT2RS intercoolers, 200 cell cats (get these welded in place of factory) and a conservative tune (there really is no point in going aggressive with a tune since these VTGs run so damn hot anyway and any hp gained in 1st second and third gear will be be lost in heat when you get into fourth) boost levels no more than 1.5/1,6bar. You'll need the 890NM clutch and I would strongly advise a Guard billet LSD (they really transform the traction and handling).

X2 I have GT2RS intercoolers on order and being installed this spring. I generally don't have an issue with heat soak at Mosport, only on one of the smaller tracks is the power loss noticeable. Also thinking of an IPD plenum as well. Had one installed in my 996 TT, I think it did make a difference.

TB993tt

I am told the IPD plenum has been tested on the engine dyno ie steady state torque measurement on a 997 turbo engine and there is no peak gain (I think there is a small loss IIRC)

For the amount of these plenums which they appear to be selling I think it is ridiculous that they don't have proper dyno before and after analysis (using a set testing protocol) for all applications, similar to Akrapovic, Supersprint etc.

There is one Mustang dyno sheet on their website for the 997 Turbo whose before graph curve is just ridiculous and should never be used for comparison.

For me lack of proper data when selling performance parts = large snake oil potential.

Having said all that I use IPD's Y pipe and it is a nice piece and you probably couldn't measure gains from that piece alone but as part of a system for more airflow it more than likely contributes in some way.

sharkster

Keeping the GT2 revival going here

TurboS

[QUOTE=sharkster;12026500]Keeping the GT2 revival going here

Fantastic! TINS!

roketman

That was awesome ! Thanks for posting!

sharkster

[QUOTE=TurboS;12026713]Cheers mate!

Thanks man! Gotta keep the GT2 flag flying... even if it's a British one

enduro911

TB, when RS puts the engine on the engine dyno, how do they know how much to cool the engine to simulate the amount of air flow that it will be receiving once it is shelled into a car, particularly one that will be moving at different speeds? I have read much about cars going on to a chassis dyno, regardless of how representative they are at showing "Porsche" horsepower, and producing numbers lower than expected because the ICs are not getting sufficient air flow that would be there if the car were moving, particularly at higher speeds.

My second question is how they go about establishing a good, powerful and reliable tune once you start adding different, non-stock components to the car. To flesh this idea out a little more, I'm going to assume that once they have an understanding of the base tune they know the correlations between certain parameters such as:

- the amount of air entering into the IC at
1) different speeds
and
2) with the stock aero kit
- the efficiency of the ICs' performance at certain temperatures
- the amount of heat produced by a particular set of turbos at different rpms, compressor speeds, and boost levels

If that is the case, I think I'm comfortable with the notion that they can adjust the cause and effects of different variables on the standard tune (basic algebra, isolate one variable such as boost pressure and watch the other correlated variables such as IAT change as a result). However, I'm interested to get your take on how they are able to reestablish an understanding of how each variable changes after something new, such as different IC ducting, is added. Surely something like better ducting would allow them to opt for a more aggressive tune if the air flow to the ICs was sufficient. I'm probably not explaining myself well but to me the "magic" is the understanding of just how far particular components can be pushed so that performance is not left on the table.

TB993tt

They use the water cooled I/c to hold the IAT around the threshold of safety ~50C in the 997 turbo from there it is methods developed over years of testing,racing,logging,destroying while testing etc obviously once in the car things will vary according to speeds hence the variable pod intakes which they are using on that new racer which can have more or less core cooling according to track.

There must be some truth in what you say about chassis dynos and limited airflow compared to on road but this does beg the question how can you accurately tune on a chassis dyno since if you log IATs whilst doing the power runs and the IAT goes too high causing timing pull/boost pull/mixture enrichening then what do you do ? how can you determine where to put your numbers if the ECU is already pulling everything ? do you guess where it "should" be on the road with increased through core airflow ? another element of why chassis dyno tuning is majorly compromised (particularly for turbo cars)

For racing the bigger concern is the low speed on the track combined with maximum heat.

I think you pretty much know the answers. I think it starts with the speccing of the build so that everything works on paper which can involve technical drawings and detailed calculations together with conversations with top tier suppliers of cams, turbos etc. Following the build it goes on the dyno to see if everything works how it should and is optimised. I know for eg that they have 3 or 4 different sizes of carbon intake pipes (turbo comp inlet) so I guess they may opt for a biigger/smaller one depending on initial testing. Same with turbos , they never go for maximum power (apart from specific engines) and will try different sized turbos to give the best area under the curve.

This is all stuff that "everyone" knows but as punters (well you may not be, you may be an expert I don't know) we should consider does the "tuner" doing 8 second sweeps on a chassis dyno really have anything like as good a handle on the data coming from the test engine as a controlled steady state torque measurement on a (Porsche turbo) specific engine dyno .

If an new component is given to them to test (I have done this a few times) they test it by sticking it on the relevant engine and running the dyno and they can see clearly if it makes more torque or not. Most parts do not.

What is interesting is that because I always seem to be banging on about other tuners overstating their "Porsche" power it makes it sound like RS is very conservative and one might imply that he doesn't push the boundaries ?

This is very far from the truth. He won't mess with the A91 engine after destroying an early 997.2 turbo motor whilst building up the torque a little, he regularly tests to component failure. When my engine went from VTG to K24 the pistons used in the initial ~730hp build passed their limit and one failed on the engine dyno, see pic below, this was after a thorough beasting, it is now equipped with stronger pistons which I understand are from the 1054PS Alzen Mission 400 build.

sharkster

James here has little to no interest in building the 9a1 stuff too;( I mean it says a lot that motorsports just doesn't race it and not even in the 991 gt3 cup cars. It just isn't an evolution of a 901, 964 etc... either... not related at all. I know we were spoiled with the GT1 based engines for all these years

TB993tt

And to really finish the 9A1 off it is being phased out with the 991 so not enough out there to justify any development costs.

sharkster

aye I just can't seem to get my **** in gear on it either I'll stick to the olde gt1

enduro911

TB, thanks very much for the response. I agree with you that because the variance in temperatures on turbo cars is so great that pinning down the correct tune using a chassis dyno must be extraordinarily difficult nigh impossible. Perhaps someone more educated than I can shed light on the situation?

That said, I honestly believe that for the vast majority of people look for more boost, more temporary horsepower, and for less money, a less-developed tune (don't have any particular tuner in mind here, merely a conceptual product) are perfectly fine. If you're not on the throttle constantly the quick dyno pull should represent your real-world use. It's when these components are stressed that the extra Porsche quality, IMHO, is shown. I have enormous respect for the durability of these cars which is why it saddens me to no end to see the direction that the cars, even the GT3s, are taking by moving away from the Mezger to products that are not being put through the ultimate test, professional endurance racing.

I also didn't mean to imply that RS leaves HP on the table. Congrads on your new pistons. Does this mean we get an update on your Ultimage VTG Engine Thread? I'm still waiting for you to throw that engine in a Cup car and enter it in a 24 hour race.

TB993tt

I think you are 100% right with what you say above, but the problem is it really muddies the waters and it ends up being the poor old punter who isn't really getting what he thinks he is. Case in point the MW GT2 with crank 775hp. It is doing 140mph 1/4s according to Sharky so it seems it does have its 775hp for a quarter mile but I guarantee you if they sold that kit to a punter in the UK and he came to one of our vmax days the car would do about 200mph which is 650hp territory, 5th and 6th gear loadings really heat things up.

I won't be doing any racing it's not really my thing, I like using the car everyday on the road, I relish the privilege of playing with a very high powered car on a daily basis.

Here is a little schematic I found which is the intercoolers referred to on this thread.

turbofever

i plan to buy a set with the 997.2 shrouds - can anyone confirm these shrouds fit the 997.1 bumper and mounting points line up identically? pls

yes it may cost $800 more although i just prefer having it all bolt in with zero modding.

sharkster

Would someday love to do that. Would be fun... Talked about shipping the 4.1 there for a few other fun reasons. Maybe someday will make it happen. Agreed that 5-6th is a different kettle of fish. VTG's and heat makes it tough. 68m vtg's probably aren't at their best with cats, I'd need some better IC's too. The dyno and street tuning work we did honestly came to a point where we didn't want/need to run higher levels of boost either for a few more seconds of glory (and extra heat). For the maps we have using around 16-20 psi depending on which map/gas is loaded is about right too. I don't have wiggins clamps all over the place and the clutch can't handle much more either... The 997tt intake manifold, plenum and use of a gt3 TB helped as well btw. Mid 650whp here on these chassis dynos is probably about the same as your 650 out there. Dynos here are done in 4th but a lot of data logging is done from mile and 1/2 mile events too.

The 775 is from a lot of parts we use from Evoms and that kit. We add/do a few other things on top of that but if someone asks me how much power our phase1 Kit (that's what we call it) makes I just say mid 600s (as that's what it makes on 93 on a mustang). The flat tq curve we have is pretty sweet though and more important than the peak. Makes it pretty useable/fun.

If I wanted more power I'd probably dump those for some better Garrett style turbos with open waste gates... No cats etc but it'd be really loud, dirty and polluting too. I know there are a bunch of straight line 1/2 and crazy 1mile cars out there with insane mph but my stones are too small. Besides my wife drives it to cars and coffee so