1971 Buick 455 GS F/SA G/SA Build

[Mark Yacavone]

Originally Posted by Carguy49

What rear end gear is in the car now? You might be surprised how little gear a Buick needs. I know of a 455 Pontiac stocker (same theory as a 455 Buick) that only runs a 4.10 gear and will run in the mid 10's.

Ron, The 455 Buick has a much shorter stroke and a bigger piston.
Just sayin'

[HP HUNTER]

Keep in mind I NEVER get in near sea level conditions. Glenn you've seen the previous dyno data how would run the gear stack? Gear ratio is 4.10 12 bolt.

[HP HUNTER]

Originally Posted by Mark Yacavone

Ron, The 455 Buick has a much shorter stroke and a bigger piston.
Just sayin'

I agree, in my line of thinking, first I need to get the car out of the hole, more gear, more converter, less internal trans weight, at this point I can deal with the first to second gear drop, but a 1.53 60 not going to get it done, theres lots more there. I believe a 4.10 gear could work in a 29.90 baro but I never see that. So with a 470 CU IN engine with head flow in the 220s @ 28" I think I'am going to concentrate on the heads and intake in that order after the short block is freshened with a modern ring pack.

[Dan Fahey]

Suggestion.
Check out Dick Millers website regarding your type suspension.

D

[HP HUNTER]

Thanks!

[goinbroke2]

Just throwing this out there...I see you're testing at 600rpm per sec (which is standard) did you (or would you consider) dynoing at 300rpm/sec? The reason I ask is it has a heavy rotating assembly and a super steep gear might actually slow it down as too much torque wasted spinning up the heavy internals?

Like I said, just throwing it out there....food for thought as it were.

[HP HUNTER]

Originally Posted by goinbroke2

Just throwing this out there...I see you're testing at 600rpm per sec (which is standard) did you (or would you consider) dynoing at 300rpm/sec? The reason I ask is it has a heavy rotating assembly and a super steep gear might actually slow it down as too much torque wasted spinning up the heavy internals?

Like I said, just throwing it out there....food for thought as it were.

I did test at 300 RPM/sec, not much difference in power output. The fast F/SA Buicks 315/330 HP run a 4.30 gear and turn 6600 RPM in the lights, and run 10.80s @ 450 elevation. Its important to note the 315/330 is a whole different animal than Jason Lines C/SA combination.

[pfordamx]

In stock your not suppose to be able to do anything to the heads and intake besides a valve job right? although judging from your other post and that you seem to have a in house dyno and who knows what other equipment your probably perfectly capable of altering that to your advantage.

[Dion Hildebrandt]

Originally Posted by Dan Fahey

Suggestion.
Check out Dick Millers website regarding your type suspension.

D

Been there done that, it is good street car stuff.