Damm sounds like some monster's you guys have

 

Well large turbos ---->lag at low RPM
Small turbos--------->"lag" at any RPM...

 

a properly set up single turbo set up can and will spool just as quick as a twin turbo setup.

 

Craig,
The units we use have all that built in now if you want to load it in. That is nice part about what we have as far as the kit. Plus if I was daring I could actually control all the systems on a TT motor for cams, lifters etc. Lots of goodies in the new version.

My issue with early motronic is the size of the maps. They are tiny compared to the resolution we have now not to mention the sophistication of the ECU 80s technology compared to 2006. So many things have changed. Also batched versed sequential and so on. Actually to many differences to list out..

Bottom line is find a tuner that knows and works with a system. If Todd was in your back door that is hard to beat.

 

What kinda power do you have in your 965?

Christian

 

Red 9-

The traction control system I am using is from England. I can't remember the manufacturer. The system is switchable between totally off, dry, and wet. It was designed for forumla one cars. The system is totally seemless. It is almost impossible to feel it working. The car seems quicker with it on than off. It is nothing like PSM that throws you into the windshield when it kicks in. Also when going through a turn my system does not upset the car at all (unlike PSM). The traction control is adaptable to any car. I will be installing it onto my GT2 after it is tuned by proto-sport.

Craig

 

Craig,
Interesting setup, please share some performance numbers once you are done. Might be going with twin GT35Rs in a couple of months (Markski's car permitting ) to replace my older turbos. Apparently they have less lag despite being substantially larger, should work well with a 3.8 engine.

 

I believe the system you have is Racelogic. Works very well on ViperTT and Supra. I am also thinking of having it install on my GT2 to put the new found power to the ground. Let me know who you use for installation. Woodhouse.com is the only dealer in the US.
http://www.woodhouse.com/index.asp?p...ss8qg8svng6vdf

 

Yes sir, ALOT of people use that opposed to the Motronic, man that setup is awesome! Joe is going to need that for his GT700 GT2

 

Vincent - Yes it is Racelogic - great system

Jean/Christian - 528 RWHP at 1.1 bar can go to 1.25 in short bursts. When I had the engine built I had the intercooler designed to be changed over to twin turbo.

Jean - the GT35R is a great turbo, of course I am running a single application. I had a K27HFS prior to the motronic. Garrett turbos have their own evils, which Stephen at Imagine could probably explain better but they are not best suited to a Porsche. The KKK is better designed as air cooled turbo. The garrett being ball bearing allows it to be more efficient but at the same time wear faster (oil/water cooled). Once again I am not an expert on this. The 3.8 should be a true beast with the GT35R's

Craig

 

I agree 100%.

The reason 930's were laggy was due to low compression and having to run large exhaust housings on the turbos due to the engines being air cooled. Running tighter exhaust housings create more heat and on an air cooled engine it is harder to manage this extra heat. This is not as much of a problem on water cooled cars as you can improve cooling efficiency by using a larger radiator, running a higher water/coolant mix, etc.

Bottom line, you can have a single turbo spool up as well as twin turbos.

 

wilbe lots of lag, placement is hard since its a flat 6 if it was a straight 6 it'll be a different matter
lag willbe a *****...

 

There is more to it than stated above. The 7 to 1 compression in the 3.3 is one component. The big lag also comes from the stock headers which run roughly 4-5 feet of tubing all over the vehicle before it gets to the cylinders. Shorting the header tubes and eliminating the cat lowers the spool. With the K27HFS, headers, and cat bypass I was at full boost at 2600-2700 RPM. That is real low for a single turbo car.

Craig

 

Good points.

I'm just trying to point out that the lag is not because of going from 2 turbos to 1 larger one but rather other things such as compression, large exhaust housing and what you detailed in your post.

 

Lag is due to a bit of all of the above. A larger turbo certainly will have more lag. The more efficient GT35Rs will reduce that lag seen over the less efficient and older turbos. You do need to make modifications to your exhaust and breathing for sure if you want a balanced setup. Another good point raised above I believe is that on a single turbo setup the turbine blades will wear somewhat faster than on twin turbo setups.

As far as life and reliability of the Garretts, I do think that they have a shorter life, but that is due to their tighter tolerances that make them more efficient. You will not see many German tuners using them because of TUV restrictions etc..
Water cooling is needed after you switch of the car to protect from improper shutdowns and coking the turbos, you can easily run oil cooling through the center section instead of water and they will last for very very long, no heating issues whatsoever while driving unless of course you are running them outside of their efficiency curve.

The only other disadvantage I know of from going with Garretts is the cost involved in fabricating the flanges and intake/exhaust system that goes with it. Their efficiency is by far better than any KKK.

Craig, I am a bit sceptic when it comes to associating a car's performance to a dyno run from a chassis dyno, many parameteres involved, I was wondering if you had any real life acceleration figures. Thanks a lot for sharing however the numbers, they look very good.

Great setup!
Cheers