My Buick is slow. Need to know why.

[BMR]

Motor is fresh, trans is fresh with D5 converter. Everything seems good. Car drives nice, has good manners. But it is not as strong as it should be.I have it tuned in on 18psi on 93. Stuck a wideband on it today, and afr is 11.7 in high gear at WOT. It will not get out of the 9s in the 1/8 at 79. Should be running low 8s at 83+. It went 8.65 at 83 with the slipping KCF trans and a D7 converter. No codes, no KR. I'm at a loss on what to check. Its on hard street tires, but traction is not a problem leaving on about 6psi off of the ebrake. I'm stumped.

 

[fast86gn]

What are your mods? 11.7 is fat. What chip are u running?

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[john keskes]

what other changes?

 

[BMR]

Crap, thought I had it in my sig. Sorry. 86, TE44, 206° flat tappet, k&n, walbro 255, vacuum brakes TT 5.7.

 

[BMR]

slipping trans

It has a BRF and D5 now. It went quicker/faster with the KCF and D7.

 

[john keskes]

wow faster with D7. which has a much lower stall.. was the D5 re-stalled?


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[BMR]

what other changes?

Changed module/coil, and maf. Not in search of performance, but because they were malfunctioning. Bwd Ignition components, factory maf sensors.

 

[BMR]

wow faster with D7. which has a much lower stall.. was the D5 re-stalled?


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D5 is supposed to still be stock specs. But honestly, I can't tell any difference between the two stalling the car.

 

[BMR]

I have an original D5 from a MCSS, but I hate to put an old crusty converter in my fresh BRF.

 

[TType85]

What 60' times were you pulling?

 

[BMR]

What 60' times were you pulling?

Short times suck. 2.0X. No traction problems, just chirps the tires leaving the line.

 

[BMR]

So I'm the only one that has ever had a problem with their Buick being slow on 18psi for no apparent reason?

 

[aminga]

Specs on the cam? Installed valve spring height, spring pressure .....

 

[Mr.Spool]

So I'm the only one that has ever had a problem with their Buick being slow on 18psi for no apparent reason?

You made alot of changes and at 18psi on a very mild combo and tune with no traction is not going to yield good track results.the car is soft all the way through out the run.

 

[Brandon#]

Do you have a catalytic converter? Nevermind just read all of your sig

 

[Mr.Spool]

I personally wouldn't yank the d5 to put the old one in for 3mph in the 1/8,I would put some octane in the tank and put some boost into it with some real tires.a 44 should run low to mid 7s in the 1/8 with an aggressive tune and traction.

 

[Mr.Spool]

It has a BRF and D5 now. It went quicker/faster with the KCF and D7.

Was that with the stock cam or the 206?

 

[Pronto]

First place I would look at, if your valve train is set up correctly, would be the converter. Next would be boost. That 44 needs more boost to wake it up. What exhaust are you running?

 

[BMR]

All runs were with the 206 cam. The engine had a spun rod bearing when I got the car, and had a 218 cam. So when I rebuilt the engine, I went with the 206 because that was cheaper than a stock replacement. I agree that is has a soft tune, but nothing has changed to cause the drop in et and mph except the torque converter. I talked with Dusty Bradford last night and found that not all D5s are the same. We have concluded that the converter I have in it is a MCSS D5.

Thanks to everyone trying to help. It has just been frustrating me that I know it should be much stronger than it is...even on a soft pump gas tune.

 

[Pronto]

I know a guy that did a build very close to yours. His tranny shop got him a new converter for the tranny build. Same issue. Not enough stall and the power was not impressive. Replaced the converter and ran much better.