This is my 91 GMC Syclone. It is #2877. When I bought it 3 years ago it was
stock down to the paper airfilter and it had 62,000 miles on it.
When I first bought it I took it to the track to get a baseline. Felt kind of bad
it was at best slow. The tracks here in Arkansas are 1000' tracks. Well in stock form
it went 12.3 @ 89 with a 1.85 60'. I continued to work and finaly got it into the mid
11's 1000' with evey thing stock except for a k/n airfilter. Then let the modding begin.
With the stock turbo I got it down to 10.56 @ 95
It has sence undergone a few changes.
The stock liquid to air intercooler has been replaced with an air to air.
The a/a has 2 1/2 inlet and outlet. It fits behind the grill for good airflow.
Feeding the a/a is a pt61 turbo from pte. It has a 3" inlet and a 2"outlet.
It will suport 630hp. I am running it at 26 psi. This is alot of boost on
the stock motor.
I also have a 3" down pipe with an external wastegate from ATR. I had a few
problems getting the w/g to work right but with a lot of work with a grinder
it works fine now. I covered the d/p with heat wrap to try and get the underhood
temps down.
It has an aftermarket chip and injectors. The chip has 2 timing levels
and 7 diff. fueling levels on each timing level. It has #50 injectors they
are supose to suport a little over 600hp. Dont think I will make it there without
opening the motor. It also has a walbro 255 fuel pump and an adjustable fpr.
And with a little help from an alki injection kit I run it on 93 octane pump
gas.I am running at 115 psi on a m15 nozzle set to come on at 6psi of boost.
I have a 3200 lockup stall converter for the trans. It helps with the spoolup of the bigger turbo.
Looks kind of funny because it is a 9" stall with a 11"
lockup clutch in it. Works great!!!! By locking the converter when it is in second gear at the strip I gain 2mph and about 2 tenths.
It came with 245/50/16 tires stock on 16" rims. And with AWD it made for an impressive
stoplight monster. 0-60 in 4.8 sec. Standing 1/4 in 13 flat at 100mph. And it
didnt take a professional driver to do this.
I have upgraded to a set of Zr1 rims 17 by 9 1/2 in the front with a 275/40/17
and a 17 by 11 on the back with a 315/35/17. It hooks good. (for street tires)
With the above changes it has now gone a best of 9.54@105 1000' And a best 1/8th
of 7.34@94 With a 1.61 60' still on street tires not d/r. Which should put it in
the mid to low 11's 1/4 mile. Not to bad for a 128,000 mile v6.
