Thread: Ran a 12.3 @110 (Do i go smaller pulley?)

Ran my best of 12.3 @ 110 last night with hoosiers and I love them! I feel the car is limited as I will get some KR with 93 and a bottle of boostane 116. When I go to the track I will add another bottle and get no KR at all. Rather do this than lower timing. With that if I reset the trims I will be an 11.8 afr like last night but after a week it will trim it self back to a 11.5 afr. Now I know the m90 is not very efficient after a 2.8. IS it really worth it to drop to a 2.7 or 2.6? Rather than find a ported gen 5 and adapter in 3 weeks before the track closes. The car is pretty stripped and weights 3375.


https://www.youtube.com/watch?v=3yH80HMLQeo

2002 Regal GS Running 12.3 @ 110 - YouTube

meth would let you run more timing. seems like we got the same set up other then you have a cam, i got rockers, im at 21º wot with meth.

Nice times.

What are you running for timing? You might gain more by advancing it on 93 octane versus dropping a pulley.

Also, what are you cutting for a 60ft?

time slips say 1.8 ish.

Missed that. Are you running qtp's? Your 60ft definitely has room to improve. You've got an 11 second car there with some tweaks.

You should advance timing to around 19° if you can run that much without kr.

Get that 60ft into the 1.7's. Cable the rear and let air out so you aren't spinning. You'll be really close to 11's.

Originally Posted by GTPpower

You should advance timing to around 19° if you can run that much without kr.

Get that 60ft into the 1.7's. Cable the rear and let air out so you aren't spinning. You'll be really close to 11's.

A month ago when I ran a 12.7 @109 I was trying an 11.5 afr and 17* of timing and I got some KR but it was not my best run as the trap suffered a tad. I will try and go 17* of timing and see how it goes. I am really looking for another 12.3 or 12.2 pass in the next 3 weeks before the track closes.

If you aren't traction limited, a smaller pulley will decrease your 60ft. That will usually help your 1/4 mile time more than a few extra hp from timing.

Originally Posted by GTPpower

If you aren't traction limited, a smaller pulley will decrease your 60ft. That will usually help your 1/4 mile time more than a few extra hp from timing.

The video is above for perspective on my launches. I know a smaller pulley will need a tweak in the tune as it is making more air.

A pulley alone won't require a retune. The maf measures air and adds or subtracts any fuel needed.

I went to check my gen3 and I don't have a machined snout so I am stuck with the 2.8 unless I buy the machine tool. I will try another * of timing to see what happens. I am shifting at 6200rpm. I looked at my dyno sheet and it says no more power is made after 6k but per zzp it says power is made to 6200.

im on a stock cam, but tried shifting at 6200, rockers and springs, the time spent spinning just rpms and no power slowed me down. backed em down to 5800 and went faster.

If you're only making power to 6k, I wouldn't shift any higher than that.

Originally Posted by SgtMarshal

what valvesprings are you running?

130#

I am going to try and attach my dyno sheet as the thumbnail will not let me anymore or delete for some reason.

I'd shift at 5900 with that dyno.