Few videos from this weekend at the drag strip. Suspension changes fixed the traction issues I had last year. I was able to pull all the launch retard out of the tune and still get it to stick. Next step will be to reduce the boost ramp from 1.5 seconds back down to about 0.8 seconds like I used to run. If I can get a 1.42 60’ again or better it is easy 9 second run, even with the extra weight the 4T80 added. Best run on stock computer, 4t65 and 6262 turbo was 10.007&138mph. Approximately 200lbs heavier now and only running 1.549 60’, getting a 10.047@138mph is very encouraging. The new PSR 6466 turbo seems to be helping as well as I only ran a 10.20@135 in 20degree cooler air last fall with the Precision 6262.
Wow ! Very impressive 1/4 mile time with a 3800. Do you believw that using a GM 6T45 have gotten you into the 9's? .
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Dennis, I’m assuming you meant 4T65, and yes at the weight I was with the 4T65, it likely would have ran a 9, but only with a $$$ built 4t65 would it be possible reliably.
This is a stock 4T80 that I have had in the car over a year that cost 1/4 or less than my old GMRacing equipped 4T65(1” chain, aermet 100 input shaft, Z pak 3rd, etc,etc). I broke both styles of zzp input shafts and multiple 7/8” chains in less than a year with the turbo before getting the GM racing stuff. 4T80 is heavy, but so far has put up with everything I’ve thrown at it, the 4t65 didn’t even survive a month of street driving/tuning before breaking first input shaft and stretching first 7/8” chain in 2012.
[This message has been edited by LFiero67 (edited 06-11-2025).]
Realized I didn’t post the changes to suspension I made.
Removed bump stops in rear to give extra travel, moved up to 325lb springs vs 275lb and raised back of car about 1/2”. With this change I was able to remove all launch retard from tune. Next will be reducing the boost ramp from where I had it to more closely match what used to run.
Currently 11lb max launch, holding for 0.5 seconds and ramping to target boost in 1 second. Total time to target 1.5 sec.
Old setup, 9lb max launch (or snapped axle), ramp to target in 0.8 seconds. Total time to target 0.8 seconds.
Hoping this gets the car back to running 1.4x 60’ and possibly even get into the 1.3x range.
[This message has been edited by LFiero67 (edited 07-25-2025).]
Dennis, I’m assuming you meant 4T65, and yes at the weight I was with the 4T65, it likely would have ran a 9, but only with a $$$ built 4t65 would it be possible reliably.
This is a stock 4T80 that I have had in the car over a year that cost 1/4 or less than my old GMRacing equipped 4T65(1” chain, aermet 100 input shaft, Z pak 3rd, etc,etc). I broke both styles of zzp input shafts and multiple 7/8” chains in less than a year with the turbo before getting the GM racing stuff. 4T80 is heavy, but so far has put up with everything I’ve thrown at it, the 4t65 didn’t even survive a month of street driving/tuning before breaking first input shaft and stretching first 7/8” chain in 2012.
I have no familiarity or info on that trans, other than GM rated it as a “45” strength which implies I would break it even faster than a 4t65, however not having a chain, it may live slightly longer unless a hard part breaks, ie input shaft, gear, differential. In a quick search, I see they also made a 6t70, 6t75 and 6t80, which would be stronger, but weight is between a 4t65 and 4t80 at 225-231 lbs. Not sure how you would program or control the internal controller, but it’s not something I am going to be running out and trying. First gear would be completely useless for me, and clutch to clutch shifting must be re-calibrated for higher horsepower to prevent slipping and failure.
Additionally the 6t80 was only ever used in one car, making supply and support very limited, though the 70 and 75 should be more available, as they were in many GM vehicles on 3.6l engines. None of these engines use the GM metric bolt pattern, so an adapter plate would be needed.
Perhaps if someone figures out an adapter, mounts, control, and I can no longer get 4t80/parts, I might try it, but for now I am pretty happy with the results with the 4t80.
[This message has been edited by LFiero67 (edited 06-22-2025).]
Ran the 100’ Dash at local Street Machine Weekend a few weeks ago. Tried launching a bit harder and ended up doing a 100’ burnout. Going to have to play with the suspension and tune a bit more to get this thing launching like it should.
Tried a bit slower boost ramp on second run and it was a bit better, but still lost the tire, no video of that run.
Went and ran a no-prep airport race today, new best 1/8th mile for no-prep, and then another new best. Third run in the cash days race I lost the tire and got driven around, though he probably would have gone around me anyway.
Had a great time, drove home and ready for next outing.
