ca993twin

Does anybody have any ideas what my lowly, virtually stock 993TT will do 60 to 130? <7 seconds must be one gigantic rush. You guys are going to drive me to the poorhouse.

ScottMellor

Steve, Lets go find out! I'll hold the stop watch.

Bill S.

From Car & Driver Magazine:

60-130 MPH:

993TT: 13.4 sec
993TTS: 12.2 sec
Viper (450 HP GTS): 10.8

A CTR does that in HALF the time. MUCH faster!

911/Q45

Is this in 6th gear?

LAT

Geoffry,
are you certain you are getting 100-105 HP/LT at the rear wheels on a N/A. On a 3.6 engine that would mean 360-378 HP at the rear and therefore even with parasitic loss of 15% you have about 450 HP at the crank. I call BS on that one, sorry, you are in now in Turbo country with a N/A.
I agree 100% with your description of the knock sensor system and its operation.
I have owned many Porsches over the past 20 years but I have never worked on them.
I am confused by your descriptions of the Porsche engine, the pistons in particular. You say "The hemi head design of the Porsche engine places the spark plug on one side of the head" yet later you say "Porsche being for all purposes a flat top piston". If the latter is true then twin plugs make little or no difference, as the combustion chamber is wide open, if the former is true then you may have a discussion. Being that the Turbo has a low compression ratio to accomodate the boost it stands to reason that it would be a fairly flat top piston. Which goes back to the position that Ruf must be taking that it does not make a difference.
I believe that the only reason to have dual plugs is if you don't have knock sensing capability in your motor then the dual plugs give you an additional margin of safety not more power.
Just for interest which Dyno are you using in your shop?

Regards

LAT

Adam T
wow, if your 0-60 is in the 3.5 sec range you are in the low 10's from 0- 130.
Have you ever run the 1/4 mile if so what were your times?

Regards

Geoffrey

LAT,

Check your math - 400hp / 3.8l = 105hp per liter. I can get anywhere from 375-412 from a N/A engine depending on configuration, fuel, displacement, etc. I primarily use either a Dyno Dynamics or Dynapack Dyno, but at times use a DTS engine dyno.

I'll give you some time to think about your statements regarding the combustion chamber and flat top pistons. I'm sure once you think about the time vs crank angle physics part, you'll understand why twin plug Porsche cylinder heads are much better and can provide better perfromance. Both my statements are true about the combustion chamber and piston.

Rassel

I've shown this one before:
http://www.spezialmotorer.com/
Look under projects, 418HP 3.2L NA with Carbs and Muffler system

It is possible, but very expensive.

ca993twin

When I was IMSA and SCCA racing, I got 291 engine dyno HP from 2.7 liters. This was an edurance engine, and basically built from RSR components with special head porting. It had Webers, not the expensive slide-valve or high butterfly fuel injection. This was really a low budget engine (at the time).

LAT

Geoff,
I guess I lost the BS call.

Hey, 418HP from a 3.2 is impressive and more so it the 341 Lbs of torque, even it its at 6,000 rpm. I was talking about a daily drivers, the Harley example I gave you uses a singe 40mm carb and is just as comfortable cruising to the corner store as it is at the drag strip. It idles like a stock bike and gets 49mpg at 85 MPH across country. I thougth we were talking street engines, not race engines.

We can agree to disagree on your latter comment.
Regards

TB993tt

As I have posted recently it is about trusting your tuner. Rassel posts this Tuner who obviously has a great facility and builds some seroius kit BUT.... he is using a TTP/Cargrahic/FVD intercooler on a993tt engine and claiming 600+ hp. I have just done a back to back test on this I/C versus the stock I/C using an Andial before/after guage and at at steady 100mph (which isn't in positive boost but it is warming up - maybe 100degF) the standard I/C was 8% more efficient - just like my tuner said it would be - hence why I have put it back on for my recent expenditure in procuring a bigger torque curve (hopefully)
So, for me, I would be thinking why is this tuner reccomending and using the aftermarket I/C, it could be that the customer insisted like I did first time round or maybe he just is not that good ?
Re. Geoffery - he appears very knowledgable but his hp claims for modifying the 993tt, for me are just not credible

Geoffrey

Toby, that hurts...

Lat, I figured we were talking about performance engines. I know I can easily produce 320hp out of a 3.6 engine using stock parts, (heads modified), chip, and exhaust so that is more like 90hp per liter...on a street engine.

LAT

I think of a 320Hp 3.6 as a performance engine, semantics I guess.

This thread started with 60-130 times on street cars. The original post was for a Ruf car, which as you know are performance street cars not race cars. If you enjoy driving it to the corner store to get milk its a steet car.

I went to your website for the first time, looks like you have a good background. I would like to see a tuner face off some day. A Ryder cup style challenge, with all the usuall European and American suspects. You know the ones, Ruf, Andial, 9ff, Powerhaus youself if you are interested etc.,

Regards

Kevin

Lat it will never happen.. They have to much to lose. We just had a 996TT, and everyone was invited.. Ruf, Gemballa, and everyone else.. Excellence will be printing the results next month

Rassel

TB993tt,

I'm' not going into any arguments with you about this, since I've done it so many times before. The Race engine has a more serious intercooler. I recall you where the one who recognized it as a GT2 EVO Secan $18000 intercooler.

The street GT2 has a funny story behind it. Dad owns GT2, son owns TT. Son tunes TT and blows dad away. Dad tunes GT2 blows son away.

FYI, the company usually works racecars and not streetcars. Last time I checked, he had an old F1 engine lying around..