A few performance questions?

[Swaggs]

Well, I rebuilt my rear end with new spider and side gears and LS clutches, also replaces my rear brake lines and drums, shoes, cylinders.. that was a job.

My questions are about power and smoke. I currently have stock lift pump, and my pump mods are smoke screw is turned in a bit, and full fuel screw is in around 3 or 4 turns and she boosts around 26-28 psi and hits like 1100 degrees.. I also have a set of cooler tubes, 3 inch downpipe to transfer case and a 4 inch from there.
I want to clear up the smoke. and am wondering if i turn back the smoke screw will it turn the fuel down enough to make the turbo boost slower, will it cause more lag?
What is my best next step? a turbo is what I was planning. I am looking for a good daily driver, good reliable power with decent mileage.
alright, thats all for now, thanks in advance

[ahale2772]

a turbo would clear up alot of smoke if u turn the fuel screw in it will kill ur spool alittle because the turbo wont have the fuel to push it but a good turbo should push enough air to make your smoke clear up

[Hoss]

Advance the timing.

[Richie O]

Advance the timing.

Timing takes away low end power. And I hate the noise.

[Swaggs]

a turbo would clear up alot of smoke if u turn the fuel screw in it will kill ur spool alittle because the turbo wont have the fuel to push it but a good turbo should push enough air to make your smoke clear up

if i turn in the smoke screw or the fuel screw> I know, i really want a turbo,
i have a 92 5 speed so it has the 21 cm housing, but i dont know the compressor size.. would it be an upgrade to get a 14 cm and a 60mm compressor?

otherwise whats a good turbo?

advance the timing.. i think that is next. well denny t is next cause its on the way. anyways..

let me know what you guys think..
i also need a piston lp i think..

[PToombs]

Turn the starwheel up so it doesn't dump fuel right away. This will help smoke and actually clear up lag from too much fuel.

[Swaggs]

yea, that seems like it would help. it smokes pretty good right before it boosts.. i havent messed with the starwheel at all.. I have to look that up

[Hoss]

Advance the timing.

Timing takes away low end power. And I hate the noise.

True, it alters the power curve… but with Swaggs desire for lower smoke levels and better mileage it would be a beneficial and low cost adjustment.

[Swaggs]

yea, my truck (along with all) has a ton of bottom end power, which I dont really tow, so I dont know how much of it I would miss..
Richie O wrote he hates the noise.. what noise does it make?
am I correct that advancing the timing increases cylinder compression?

[dpuckett]

Try a piston lift pump. With 80hp Bully Dogs, HX35/40 hybrid turbo, and a stock lift pump, I could block out an intersection (out of 5" stacks, no less) on a 3rd gear start. Installed a piston LP, and 2/3-3/4 of it disappeared. All I had was a grey haze til the turbo spooled, then nothing. Also gained 5psi peak boost.

My thinking is, the stock pump was on its way out, so it wasnt supplying the pressure the VE wanted. The low supply pressure also led to low injector supply pressure from the pump (still popped them open, but was less than optimal), which caused the smoke. When the supply pressure was up to par, the IP could compound it better, resulting in better atomization and less smoke.

Stick a gauge post- filter in the fuel line, and see what you have. If less than 5psi at any time, it's time for an upgrade.

DP

[Richie O]

It makes them sound like a 3126 cat. Mine is at least 3/16's advanced. My 93 is stock timing and it is very nice in the truck. Can hardly hear the engine. The 89 is loud in the cab. I also like the turbo response at stock timing as well as the low rpm torque. When I advanced the 89 I gained lag and lost some bottom end but with an auto it is not the end of the world. With a 5 speed ( like my 93 ) I am sure I would hate it.

[Ace]

I think the smoke screw and starwheel are pretty useless for making anything but smoke and lag after you turn in the fuel screw. I have mine backed all the way out / up, to include carving out the top of the AFC cover for max upward cone travel. That's the only way I could get rid of most of the low boost smoke.

[Jfriedlin]

if i turn in the smoke screw or the fuel screw> I know, i really want a turbo,
i have a 92 5 speed so it has the 21 cm housing, but i dont know the compressor size.. would it be an upgrade to get a 14 cm and a 60mm compressor?

otherwise whats a good turbo?

advance the timing.. i think that is next. well denny t is next cause its on the way. anyways..

let me know what you guys think..
i also need a piston lp i think..

The Denny t is just gonna add more smoke

[fergavs]

Anyone aside from Richie not like advanced timing? I run LOTS of timing on my 90 (jumped tooth, etc.) and run the 4x4 timed to the head. Both truck run better, smoother, harder. I would never go back to stock timing. As far as noise I cant say I really noticed that much on the 4x4. On my duallie with a jumped tooth and timed to the head it was too much and got loud and tinny sounding so I pulled it back a little. Seemed to solve the noise and it actually was a little more responsive pulled back a little. I couldnt imagine a 1/8" or 1/4" bump making that much difference in sound. .02$.

[Richie O]

Anyone aside from Richie not like advanced timing? I run LOTS of timing on my 90 (jumped tooth, etc.) and run the 4x4 timed to the head. Both truck run better, smoother, harder. I would never go back to stock timing. As far as noise I cant say I really noticed that much on the 4x4. On my duallie with a jumped tooth and timed to the head it was too much and got loud and tinny sounding so I pulled it back a little. Seemed to solve the noise and it actually was a little more responsive pulled back a little. I couldnt imagine a 1/8" or 1/4" bump making that much difference in sound. .02$.

I run my 89 advanced. I am keeping it there, just don't like the sound. And also I have no idea what my injectors are set at for pop. They are the original and may be poppin early causing even more advanced timing.
Im not against it by any means. I am keeping my 93 at stock timing because I love the low end it has and the instant turbo spool. On my 93 I ran a jumper wire to the KSB to see what it sounded like. I could hear the engine change tone but was just as quiet as with it unhooked. I only have experence advancing the timing on 1 truck so I by no means have a clue.

EDIT: and the timing is farther then 1/8 on my 89. May be over a quarter.