mw911

Hello,

Jean asked me to post some data on my car: its a SHK tuned 993 turbo with narrow body, RWD and rain gutters delete. More technical specifications are given in the other thread (on hard pipes).

I enclose some pictures together with a manthey dyno chart and a drift box screenshot (100 to 300 with 0.71 6th gear and 19 zoll conti vmax tires)

I used these tires at that time for some vmax measurements. Conti vmax for our cars is only available in 19 zoll, normally I use OEM 18 zoll 285/30 michelin pilot sport tires.



Michael

Jean

Michael, thanks for posting all this data That is an amazing car that you have, I love the sleeper side of it yet it has all the right things to be a very fast car!

I like the fact that the car keeps pulling up until the rev limiter, notice how your max HP is reached twice, the first time at around 5700RPMs and the second time at 7100 RPMs.

The reason you don't have rod issues is because the engine is tuned for HP rather than peak torque, you do have a nice broad torque curve but mainly the car wakes up at around 4200rpms so your peak torque is 720NM only, single plug and 3.6 engine all contribute to the lowish torque numbers when compared to the 3.8s out there. This will not make it any slower at all in high speed runs for sure. I am assuming you are running around peak 1.2 bar?

I am assuming that you have no runs with and without the rain gutters? Great combo, lightweight, aerodynamic, tall tires and gearing and good HP... what else can one ask for?

Welcome to RL.

Stummel

The car is also put to great use frequently I can assure you all...

MarkD

Very nice... it looks so innocent.

Forgive my ignorance, but what front bumper cover is that?

V

Looks like Techart, but then with the RS splitters instead of the Techart ones.. Something like that. Looks hawt regardless

SA Mike

Does deleting the rain gutters help that much?

mw911

Jean,
you are right, the engine is by purpose tuned for hp rather than torque to protect the rods etc. SHK uses sportec kits (and philosphy) for the turbo tuning.
When I was at sportec last december for another fine tuning session Gunther Mandel at a certain point (overall ca. 6 hours dyno time) had reached a much higher torque but didn`t like it and changed the settings again to reduce the max torque.
Peak boost pressure is 1.3 (if ambient temperature is hot) and 1.2 if ambient temperature is cold. Peak boost pressure is reached above 6500 rpm. Overboost is between 1.5 and 1.6. One has to have in mind, however, that I am not totally sure, whether my external boost cauge ist totally correct. Gunther Mandel stated that his digital boost gauge measured 0.15 bar less. Harry Weishaupt (the owner of SHK) argues, that with 1.05 to 1.15 peak boost 570 PS (manthey dyno in may 2007) or more (sportec dyno numbers in december 07) would not be possible.
The high overboost in hot ambient temp condition causes the problem with the boost hoses. In last summer I was behind the ruf turbo of my friend (low traffic at the autobahn). He was alone in his (also rel. light weight car with alu doors etc.) car and I had my 18 years old nephew beside myself. At tach 330 I had to reduce speed because I came to near to him. When he had gained a few meters I did wot (is this the right expression?) again, my car made somewhat between 1.5 and 1.6 bar and the hose was lost.
I then phoned the german ADAC (car assist) and told the young lady that I just had lost a boost hose at 340 km/h and that I would need some help. The lady answered "and now the car only drives 320 or what ?"

I do have a driftbox file with the rain gutters still on, I will post it on monday. However, the two files are not totally comparable, because during the run at that time (november 2007 or so) I had the 18 zoll tires on and a passenger beside.

Michael

mw911

Its a tech art front spoiler together with OEM RS splitters. The tech art front spoiler has remarkable small front openings (remember the thread of toby on aerodynamics and front spoilers) and was used by RS tuning on their first tuned 533 hp or so 993 turbo engine (which at that time was in a modified 964 body)
Behind the left opening the normal small auxilliary oil cooler is placed. Behind the right opening two large oil coolers are placed; air is drained through the right front wheel housing which by purpose is a little "open". The ventilator had to be omitted (for space reasons). That sometimes gives me a hard time if its hot outside and I am in a larger traffic jam. Air condition is still maintained.


Michael

mw911

I am not sure, I can not really say that the car is faster now. We mainly did it for optical reasons. At higher speeds, at least, the car is much quiter now. Whether this is due to the rain gutters delete or due to the elimation of the sun roof (which we also did by installing a comletely new roof) is not clear to me.

It might also be possible that the potential beneficial effects of the rain gutters delete were counter balanced by the new installation of brake cooling ducts that we did at the same time. This might add negative effects to the aerodynamics.


Michael

MarkD

Ah, thanks. The RS splitters look great with that cover.
I like it a lot. And it sure seems as if it would improve aero.

TB993tt

Michael, thankyou for sharing

Your acceleration is strong, 0-300kph in low 28s superb... I would love it if you could do a "coast down" run from high speed say 250+ to 180kph and let our gurus Jean/Juha crunch your aerodynamic data to see what improvements you have been able to make ?
Can you tell us what weight you are running and specifically do you know how much weight saving came from the sunroof delete ?

Turbodan

Looks like a great car. Much of the technical data is over my head, but I am suprised you left the stock rear spoiler. most guys that do the engine and things like rain gutter delete go with the rs spoiler or the "s" one. curious what was your reasoning?

mw911

Hello Toby,
the cars weight now (with empty gas) is 1360 kg.
The weight saving from the sunroof delete was 22 kg, however we used a whole new roof instead of welting the sunroof "hole" or something like that.

Regarding the "coast down" run I will try to do it next sunday. Even in Germany these high speed actions on the autobahn are better done on sundays at 6:30 am. "Coast down" does mean to let the car rolll from lets say 260 km to 150 km with pressed clutch pedal and neutral gearing position is this right?

I have enclosed two screen shots from the only drift box run I have before rain gutter delete, its one from 100 to 200 and another from 200 to 300. Unfortunately at that time I didn`t do a 100 to 300 run. These runs were done with 18zoll tires and a second person (40kg) on the passenger seat.

Yours

Michael


I

mw911

Danny,
when we did the initial modification of the car in 2005 (putting the turbo engine into the narrow body of the n/a car) we noticed that above 300 km/h the cars aerodynamics were pretty unstable on the front. This was cured by the addition of the OEM RS flaps (while the techart flaps didnt influence this phenomenon).

Therefore, we had some fear, that the addition of a turbo s wing (generating even more downforce in the rear of the car) would alter the high speed aerodynamics rather than improve them. One would then had to add an additional front flap (eg. the gt2 front winglets). This, however, would interfere with the aim to have a more or less "normal" looking car.

Michael

Jean

Hi Michael

Very interetsing thanks

Your car is really light! I did a lot to mine and I am still about 40kgs heavier than you. I also did the roof change and bought a Porsche Gt2 roof all together. It looks like you have fiberglass rear fenders? Are your doors stock?

for better comparison, would it be possible for you to send me your 3 files in raw format? This way I can customize the view and superimpose data..

The best part about your car is that you have the stock rear wing, I simply love it.

For your coast down runs, you do not need to go all the way to those high speeds, it will be better, however a 200-180kph coast down would be good too. Also it will help if you do a 40-20kph coast down and record both runs.

For the test, I simply put the car in neutral, no clutch.