new turbo on EFI - ideas?

[Axel84]

I am thinking about building an EFI turbo engine.

its a 77 engine, so was thinking Mahle Motorsports7;5:1 98 mm ( 3.2 shortstroke kit)
put it on Motec, 3.2 carrera intake, carillos, alot of port work etc. and Rarly8 equal length headers ( with heat)
Havent quite decided on cams yet, actually looking for midrange torque so maybe a set of 964 style cams or similar...

I was wondering if there was anything new on the turbo front - has anyone heard of Xona Rotor?

still uhming and ahing back and forth a bit on the cam side of things, seeing as I go full EFI I can get massive power by moving the powerband up but... on the other hand, i KNOW on the street that what makes you fast and have fun is the midrange, not the top end.

Input?

[Black_Hat]

I have a 1991 C2 turbo 3.3
I have had many high horsepower 911 turbos

This latest build I consulted PowerHaus I wanted a street Torque motor.

Because C2 turbo are so expensive I wanted to maintain stock (ish) CIS
I wanted everything to happen @ lower RPM
the car is a monster
Forced to Deal with This

I have since added electric steering pump rebuilt fuel head opened up for max HP.

I have my Rev limiter set to 6300 RPM because it revs so quick.

It drives off boost like a N/A 964 smooth never sputters or bogs.

[Black_Hat]

I also had my RUF K29 turbo rebuilt at EverGreen Turbo
Charlie put in a modern Raptor Hot side

Just tuning now as he weather is no longer GDF Hot in Texas

[Ollies930]

Originally Posted by Axel84

I was wondering if there was anything new on the turbo front - has anyone heard of Xona Rotor?


Input?

Xona Rotor is the company that used to modify stock Mitsu Evo, Subaru WRX and Garrett turbos with their own compressor and (I believe) turbine wheels and now manufactures their own center sections as well. Eddie Bello used the Garrett GT35 conversion turbos very successfully, first the HTA82 and then the HTA86 on his white twin turbo air cooled monster (highest dyno I heard was 1340rwhp). Very good turbos, but the Xona Rotor line may require water cooling to be run through their center sections to survive.

[David]

If I was building my engine over now I'd go with:

Motec (I'm using M600)
98mm 8:1 JE pistons (like I have, much lighter than Mahle)
Carrillo or Pauter (I have) rods
Flame ring heads (I should have)
Twin plug (I'm using 6 waste spark coils with multi channel CDI) and coil on plug (I might convert to)
964 cams (I have) or maybe a little hotter?
GT3582R Garrett (I have) but with a twin scroll turbo housing and Rarly8 twin scroll and twin waste gate (I might convert)

I don't know that a lot of port work is needed but I did machine my heads to match the Carrera intake which I think helps flow. I'm using a stock Carrera TB which by my calculations is fine for a mid 500 horse engine.

[fredmeister]

I built my 79 930 3.3 engine with those pistons and unfortunately used SC cams. I wish now that I had gone with 964 or even hotter cams knowing that I am Electromotive EFI and no longer CIS.
In my opinion the only way to insure longevity is to dump the CIS and go EFI. I have been tracking my car almost exclusively for 5 years now with no issues. Get the oil analysis done by Blackstone every change to monitor the engine.
I ported the intakes to 36mm and matched the intake manifold. Running a huge intercooler and a Garret Hybrid turbo called the X61? that I bought 6 years ago. It has a custom compressor billet wheel and a G37 center section BB cartridge. Also, Brian Bodart headers (no heat) and a Zork tube.
At 14psi or 0.9Bar it makes 390hp at the rear wheels-- no ****. Car is a monster, and it sounds like nothing else. I always get people commenting on the sound of the car on track. Thats a real ego booster, and it is not too terrible when I drive on the street.
I still think it is tuned conservatively as i told my tuner that I cant afford any more rebuilds. So with some ignition tuning optimization, I think i could run a bit more advance under boost and get some more power.....but like i said i have been beating on it on track for over 5 years and it still runs strong.
Here is some video from the last track event at Road Atlanta to give you a taste....enjoy.
https://youtu.be/-p6IMAb_2mo

[Axel84]

Looks awesome fred, Im thinking maybe some hotter cams then yeah , and 1.0 Bar of boost.
should give 450 WHP.