I would like to know the difference between our stock turbo and the HFS. Can you really feel the difference ?

 

I have the HF I don't know the difference between the HF and HFS but I can say the HF makes a world of difference. The HF turbo is more responsive than the stock K27. The first thing you notice is the ability to control the throttle more like a N/A car. The on/off feeling you get with the stock K27 is gone. When powering through a turn you can apply the throttle with much more confidence than before and it does not run out of wind above 5000 rpms the way the stock K27 does.

 

That sound great Anthony, next on my list would be the HFS . Thanks !

 

"The rest of the mods are more like putting lipstick on a pig (the pig being CIS)."..

hahaha.. CIS, yeah that's unfortunate.

The ball-bearing turbo should only affect spool up time and not increase airflow mass. 1 bar of boost is 1 bar of boost, regardless of turbo.
Now, how fast & efficient you get to 1 bar of boost is dependent on exhaust system, turbo spool, and intake efficiencies.

Seems like with these CIS engines delivering enough metered fuel is the core issue.

My car doesn't have a CAT. A wideband O2 sensor is going on. I might even get to use that independent knock sensor system I have... everything tuck away in the glove box or something.. I don't like the bling gauges everywhere.


Since our cars have a mechicanal fuel injection system.. what does the existing stock O2 sensor control?

 

It seems the path you are taking would be towards unplugging that sensor. If you search the forum you'll find out more than all you need and want to know.

 

The volume of air my GT35R puts out at 1 bar is many times more than my K27HFS did at 1 bar. So 1 bar is reletive to pressure not volume of air.

 

Correct...this is not a static system governed by:
PV=nRT

In the case of flow, the equation becomes:
V/t = [(n/t)*(RT)]/P

where V/t is the volume of air per unit time (flowrate) and n/t is the mass (moles) of oxygen moving through the system per unit time. At constant pressure (1 bar) a higher flowrate (V/t) delivers more oxygen per unit time (n/t) to the engine.

 

You guys are correct, from a mass flow perspective on turbo efficiencies.

I was commenting on the same turbo compressor efficiency with a ball-bearing instead of bushing.. (think K-27 with BB).

 

Some Questions ......any body?
When using a GT35 R how do you cool it ? do you run oil through the water bearing jacket?
Also what size oil restrictor is used to prevent seal blowout from too much Oil?

 

Where's Kevin when you need him ????

 

There is a thread over on Pelican about a 3.8 liter build running oil through the water bearing jacket.. I don't have experience with this one.

Atleast on the 944 Turbo side.. we run anywhere from 40-70 thou hole oil restrictors. Basically an allen key plug with hole drilled through it, seems to work well.

 

 

Quite easy: 964 NA is the same cam like 964 3.6 Turbo S (X50) cars. The M64.50 Standard engine is equiped with 96410524820 (right for example)

In PET you wont find the S Spec, but you can check Flachbau.com

I build some of These 3,3 and 3,6 engines and go for the cams with a 7006 Turbo like the S cars.

Regards