MOD500

There has been much talk on here about intercoolers, so at a V-max Speed Day here in the UK this Saturday gone, I got the chance to rate my Secan rack aloft the Banana's engine.

TB kindly brought his Bosch Hammer along and Ruxpin bravely rode shot gun on a run to watch the intake temperature via the Hammer plugged into the OBD port. The results were incredible ..... the Secan is supposed to keep the intake temperature (post intercooler) within 20 degs of ambient at all times, at a 20 - 21 deg ambient the highest reading on the Hammer was 40 deg on a run to 193 mph. For ref my engine produces 533 PS / 729 NM.

As a comparison, Kennyboy kindly allowed me to passenger on a run with him in his stock 408 car and watch the intake numbers on a stock intercooler. During a run to 175 mph, the average temp was 46 deg, and a peak of 48 deg. Good stuff.

I guess the moot point here is what numbers would a tuned 993 'see' with a stock intercooler if a bone stock car shows numbers 15% higher than the Secan? Interesting thought - how long will the claimed power be hanging around for during prolonged full throttle when things get hot?

More on the speed day ..... my best speed was 195 mph through the laser with the speedo just south of 200. The car felt quite frightening at such speed, and you can feel the stability peel away north of 180, as you pass through the limits the car was originally designed for

Top speed of the day was Leon S in the RUF RT12 at 207 mph, amazing

Speed tables and pics here:

http://www.pistonheads.com/gassing/forum.asp?h=0&f=133

Jean

MOD500

Quite impressive!!

Thanks for the update. IMO, the Hammer intake temp test is the ultimate intercooler efficiency test, and I wish this is how intercoolers got "tested" and benchmarked always instead of flow benches, discussions about end tank design and theoretical pressure drops.

I find the results truly amazing, and a justification for such a piece of expensive equipment that I see just as important as any turbosystem upgrade.

Don't forget that your car goes to 1.2 Bar+ whereas the stock 993TT is limited to 0.8 bar and still, you run 8 degrees lower. My guess is that a 993TT boosting at 1.1 bar with stock IC would see 20 degrees higher than yours.

Here are the results of VMAX for an easier read, excellent results, even beating the CGT, for a mere 530BHP Congrats.

Stummel

What was up with Leons 993 Ruf?

The RT12 is incredible!

TB993tt

On a badly specced engine, it doesn't matter what intercooler you use since the heat generated will be unmanagable, but MOD's 40 DegC inlet is an amazing feat IMO and is why the engine keeps virtually all its 529 hp enabling it to hit 195mph
I will share this printout with you guys, it was given me by RS to show me what my ECU did at the last vmax when it didn't have an air intake signal, it reverted to an intake of 52DegC to protect the engine - you can see this retards the timing by 4.5 (I think this is degrees but will stand to be corrected ?) which robs around 40-50hp at the mid 500s level.

You can see the importance of the air intake temp. If it can be maintained below 37.5 DegC then the engine gets maximum timing - THIS is why the intercooler is so important.


There is another set of data which shows how boost is reduced with temp increase but the timing is the most dramatic and the ECUs first line of defence (since it can reduce it very fast)
I do not know if the above data is the same for all 993tt engines, for all I know it is bespoke for my motor - but you get the gist

TB993tt

Leon's 993 Ruf had some hydraulics problems - amazing that it did what it did !

The RT12 showed how it should be done with a mix of power, aerodynamics and (often overlooked) superb brakes.
Here is a crappy vid I posted on the CGT forum -you can see I started accelerating in the CGT before Leon but checkout how the RT12 comes flying up at the end as the CGT hits its aero brick wall -you can just make out the bollards as the Ruf crosses them - it clocked 203mph on that run and the CGT 193mph................
http://www.youtube.com/watch?v=ae2PAOMBSZ8

Jean

I am surprised that the engine still has the hydraulic valve lifters, unless there is something else hydraulic in the engine

Also amazing how the CGT sustained its initial lead up to those speeds. I wonder what the 100-300kph time was for the RT12, I am guessing it has the stock 0.79 6th. gearing.

BTW, how do your "good runs" 993TT compare to the data from the CGT from 60-150mph levels?

vrus

Very interesting results... So a stock car is seeing roughly 25C over ambient..

Ok.. Now I have something to compare against..

The data I was given regarding the intercooler I posted showed 10C drop of IAT temp at the throttle body which would mean the effective change was 15C over ambient.

I am awaiting this intercooler to arrive and will do my own personal tests on it to confirm the validity of the data.. I will have the intercooler coated with a heat dispersement coating and I will do some 3rd gear WOT testing and record the data.

Where can one purchase this Bosch Hammer equipment? Is it any different than Autotap or AutoEnginuity??

Thanks for the info.. This gives me some good comparison data.

TB993tt

Hi Jean
I do not have any data up to 150 in 4WD mode, but I have a 60-155mph run in 2WD mode 20DegC driver only running weight 1465kg.
993tt 60-155 11.9s
CGT on vmax 60-155 14.54s
Based on that I would guess in 4WD and with a passenger the 993tt would take ~13.5 to 14s now ?
Usual thing tho', it really is hard to compare on different days, different venues. The airstrip has a 4 metre uphill slope for the first mile whose effect is debatable ?

Jean

TB

WOW! I am amazed at how much faster the 993TT is from 60-155mph!!!
I will need to crunch some numbers and extract your data, but I would not be surprised to see a VERY easy 200mph+ over that same distance with your 993TT.

I bet the "I'm in control" feeling is totally different though between the two cars
Thanks for the data.

TB993tt

Not with me at the wheel
1963 bodyshape with appendages versus 21st century hi tech.......no contest really

Ruxpin

The video you've been waiting for..... (Geek warning!)

Onboard MOD's 993tt reading intake temps up to 193mph. Car was in the queue waiting to run for several minutes hence 40DegC starting intake temp.

http://video.google.com/videoplay?do...34753736286869

Jean

Hilarious! Good job Martyn!

TB993tt

OMG my name is TB and I am a Geek....that video should be on youporn

MOD500

Great vids Ruxpin, thanks so much

Check out my accent, I sound proper Yorkshire!

Ruxpin

Some other clips from Saturday... Less geeky i'm afraid - although there is a tasty close up of the secan at the start of the second clip.....

Onboard Carrera GT to 19Xmph filming MOD500's RS Tuning 993TT
http://video.google.com/videoplay?do...50365172&hl=en

Carrera GT from onboard MOD500's RS Tuning 993TT
http://video.google.com/videoplay?do...12915915&hl=en