Alky question for a carbed turbo

fc227

1986 Grand National
Joined
May 28, 2001
Hello all;

For those not familiar with my setup I have a 1980 olds cutlass with a 1979 Buick turbo V6 (carbed not fuel injected) . Its far from stock , fully ported & poslished heads (cast) , forged TRW pistons , balanced , Comp 252 cam & lifters.

The turbo is not stock , It is hybird t3/t4 , with a stage III turbine wheel & "V" seires wheel on the compressor side . I run 22# on C16 and run low 13's (see sig.file). ( turbo is presently at turbonectics getting rebuilt becasue the seals , bearings and housing let go on it).

I have made a alky injection unit with a Ford F.I. pump , NOS nozzle and a .028 jet.

I have also made a a varable speed (PWM) speed control that turns on and vaires the pump speed with Boost presure use a 1 bar MAP sensor.

The question for the group is : Running 93 octane pump gas , is that jet big enough ? I have mearsured 100 psi at the nozzle so there is plenty of pressure , or is that jet to big ?

I am using isporpyl 70 % , Use I include a shot of oil with that ?

If the turbo gets back in time next saturday there is a dyno day I like to attend so I can dail this in . I also bracket race every weekend , So If i do't have to buy race gas , This will be a big savings.

The carb has 67 jets in the front , 74's in the rear , 8.5 Power valve . Total timing is 40 ° , But I am running a MSD6BTM that take 1 to 3 ° timing out for every pound of boost it see's , I have it set at 1 to 1 so at 15# of boost there is 25° of timing , plus I'm taking out and other 3° in high gear ( wired boost retard) that I can set to 0° or has high as 15° .

What is the opinon out there , that may save me some time on tuning this carbed beast :)

Thank's , Fred
 
Injecting the alky after the turbo in very, very smart. It is almost like shooting NOS. The tuning on the alky should be fine. As long as you are not flooding the motor, you are fine. There was a guy here in Alabama the had a carbed T-Type on alky and NOS in the 7's (1/8 mile). This would have to be the "ULTIMATE". I can remember seeing this guy leave on alky, spraying 125 horses at the tree. I now remember, it was in a 71 Chevy Nova. It was the damnest and unusual thing to see. He wrecked the Nova and changed to a 82 T-Type. If can dig any more info, I will post. Hope this helps:).
 
Yea, If you can find more info on the guy , I would be interrested in talking to him.

My best 1/8 mile was 8.49 @ 81.28 MPH (uncorrected) that was C16 @22#'s of boost. 3# launch.

My goal is to stop running the race gas run around 20# boost with the alky . If it is consistant . I also bracket race so consistanty is the key for me.

I suppose I could back the timing back only run 15# of boost , But then . I'll only be in the 14's , whats the fun in that :)

What size (alky) jet do you recomend for a turbo that flows around 650 CFM ?
 
So at 22# of boost you are running 18* of timing? You should be able to run at least mid 20's. Even though your car is carbed you should be able to get some type of knock detector.
 
No , 25 ° total timing @ and above 15# of boost , I use to run 27° before I got the MSD6BTM.

The car also has a Knock detector(ESC) that pulls timing out if it hears a rattle (up to 22°).

I Have run up to 12-13 # boost on pump gas with the old setup (27°) before it would rattle.
 
I would experiment with .020 - .032. Start big and go smaller till you have a little knock. Too big will cause the motor to bog
 
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