'86 GN back from the grave


Sep 11, 2003
I started about 2 or 3 months ago to bring my 86 GN back to life after years of neglect. Did all the spring cleaning stuff and all the starndard upgrades from the gnttype.org site. I had the driver side header leak welded and ignition problems fixed too. I tried a few of the well known generic chips available on this site and the internet but was not impressed with the performance of my GN. I drove out to Turbo Tune in Greensborro NC and the owner Mark looked over my GN. He went in the office and returned 20 minutes later with a chip he burned for me. My GN is now unusable with stock tires( P215-65-15's). It just smokes them no matter how I try to come out of the hole pwr breaking it or not. If I step on it under 30 MPH I go sideways. I love it!! Now I need new tires!! None of the other chips I tried even approached this level of tune. I swapped them back to double chk and they were wimpy compared to Mark's program. Thanks Mark!!!

1986 Grand National (original owner)
131,000 miles
Stock Motor and Trans
New Coil pak and Module, plugs and wires
Red's FP and Billet reg, Hot wire kit
Stock turbo and injectors
ATR 3" DP and dual 3" SS Exhaust
ATR 14" K+N cold air system
160 * stat
Mark's (Turbo Tune) street chip for my setup
Never heard of Mark. Does he burn them regularly?

What timing settings does the chip have? Lock up at 45?

Does he burn them for the same setup GN but with alky?
I did not ask Mark much about the chip. I do know that for regular driving the converter behaves just like stock locks up @ 45 mph. The fan comes on @ 180*. The cold start and warm up are fantastic. The bottom end power is very very strong. I was using BP93 with Zero knock. Mark burned the chip for the winner of the recent GN/GS, SY/TY, TTA Shootout if I am not mistaken. The differerence was like night and day from all the other chips I tried. Mark has been working on the Buick T's since '89 I think. He has a full Dyno setup ther also. He mentioned that he has a lot of timing down low and tapers it as RPM rise. This was a custom chip for my stock setup so each one will be burnt for each car. $60.00 for the chip at his shop.