Well guys I currently run a 4# and Ported blower. With just the 4# I was making 12.5-13psi or so. I added the Ported blower and it's peaking at 16psi @ 5,200 rpms but only 14psi under 5,000 rpms.
Here is where the problem lies. At the track it runs AWSOME in first and second gear with the added boost but as soon as it goes into 3rd I'm only making 13-14psi 90% of the way through 3rd gear. So I figure I leaving some power on the table.
Here's my idea and tell me if it's a good one or not.......

I'm thinking of adding a 6#er and lowering the shift points to 5,000 rpms. By doing this I think I'll run a solid 16psi through all gears and keep the rods in the block at the lower rpm. I have built trans and stall and run on full slicks at the track where my L see most of it's duty.

Is my train of thought off?

 

do you have long tubes and high flow cats.

I have never seen 16psi on my ported blower with 4lb lower.

 

I see just past 15psi with my 4lb lower and ported blower and I run full exhaust.

 

No stock manifolds and cats.
I only see 16psi at the very top of each gear. Most of the gear it's 13-14psi then it creeps up to 16psi.

 

Is that you're current best Mph in you sig with you're mods? I've been trapping 87mph and running 8.0s in the 1/8. Of course that's with a convertor and slicks @ FULL weight, 4# and Ported blower.

 

Yep Of course that track sucked.

 

isn't boost a measure of backpressure?
with a full aftermarket exhaust, you'd expect the "boost" to be lower.

 

that's what i was thinking. I was told that with my ported blower, and full exhaust that i wasn't really seeing the potential of the port with the 4 and to go to the 6.

I only get 12lbs, maybe 13 at peak boost.

I've put down 437 and 532 to the rear wheels however.

 

If your using Metco interchangable rings, I'll trade my 6 for your 4...

 

I am making 16lbs of boost with a 6lb lower/1lb upper and ported blower.

 

Something seems off? How come I make so much "peak" boost 16-16.5 psi with only a 4# and Stieg port? I'm starting to wonder if my cats my be clogging causing the extra resistance in the higher Rpms?
Granted I only make that much boost from 5,000rpms+ but it still makes it!
I'm slapping on the 6# today and lowering the shift points to 5,000 rpms. As soon as funds permit I'll be ordering FULL exhaust, fuel pumps and injectors.
I just like to make 16psi through the rpm band...not just for 300rpms. I dont know, maybe I'm just getting greedy?
The L has ran a 12.63 @ 108.90 in nice 70* weather with my 4# and port on RADIALS @ FULL WEIGHT this past spring. I'm sure in this fall/winter air coming that a 12.3 @ 110 on slicks is possible.

Should I leave it alone or slap on the 6#?

 

I've hit 17.5 in cool weather w/ my Stiegemeier ported blower and a 4# lower. Alos had hi-flow cats, maggy cat-back and stock manifolds.

 

this has been gone over a zillion times but i don't understand how people are getting 16 and 17 lbs of boost with a 4lb (12lb total) pulley????

You aren't getting 4lbs of boost out of a ported blower???


Bad boost guages?

 

OK. I've double checked my boost gauge with another boost gauge for accuracy. I was making a MAX of 13psi with a 4# lower. I added the Ported blower and I see a MAX of 16.5 psi.
So I guess you're right? I did not gain 4psi, I gained 3.5psi @ Peak.

 

Out trucks have been very close in power for a while now according to ETs and Mph. How much timing are you running?