LQ4 - Single or Twins
02-20-2013, 07:24 PM
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LQ4 - Single or Twins So I'm moving from 4.6 mod to a bone stock LQ4. I have 2 motors, one going in now junkyard style (stock shortblock, turbo cam, springs, head studs, 317's with basic head work w/basic home polishing), one going on the stand for a longer term build with all the goodies.
So my question is this... I currently have a Turbonetics T-4 76mm with a .96 a/r and a 68mm turbine. I understand that this is too small for the LQ4 so I'm left with two options as I see it. But I'm not certain which way to go.
1) Buy something like an s480 and call it a day
2) Buy another T76 to match mine and run twins
My goals for now are to run 20psi on a good tuneup on this junkyard build and still leave some room for growth when I finish up the real build.
Obviously, single vs. twins is a factor. Need to double up on wastegates and possibly BOV's. Right now, I have a single 50mm Tial Q so I'll probably just pick up another.
I'm doing the piping myself, so single vs. twins from the piping perspective is nominal.
Thoughts?
Thanks!
So my question is this... I currently have a Turbonetics T-4 76mm with a .96 a/r and a 68mm turbine. I understand that this is too small for the LQ4 so I'm left with two options as I see it. But I'm not certain which way to go.
1) Buy something like an s480 and call it a day
2) Buy another T76 to match mine and run twins
My goals for now are to run 20psi on a good tuneup on this junkyard build and still leave some room for growth when I finish up the real build.
Obviously, single vs. twins is a factor. Need to double up on wastegates and possibly BOV's. Right now, I have a single 50mm Tial Q so I'll probably just pick up another.
I'm doing the piping myself, so single vs. twins from the piping perspective is nominal.
Thoughts?
Thanks!
Last edited by Screamin'04; 02-20-2013 at 07:42 PM.
02-21-2013, 01:17 PM
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I'm thinking both units in the front corner of the engine bay and down pipe straight over the manifold/headers down the back by the firewall and straight out the back dumped before the rear axle. Using 3 to 3.5" piping (oval where need be for clearance) with no mufflers should work I would think? I'd love to do bull horns to eliminate the "full exhaust", but don't think the local law enforcement would love them.
Oh, I'm sure I will be posting on here quite a bit as I progress... I just bought my tig welder yesterday to do the piping. Next up is practice, practice, practice.
I'm also going to work out a way to emulate the 4.6 sensor signals so that the factory computer thinks that it's still a mod motor. Going to be doing a 36-1 reluctor wheel setup etc... a Megasquirt will be running the show though, the factory ECU will be a dummy in read-only so that I can uplink for DMV inspections. Have to work out the logistics, but it should be doable.
Oh, I'm sure I will be posting on here quite a bit as I progress... I just bought my tig welder yesterday to do the piping. Next up is practice, practice, practice.
I'm also going to work out a way to emulate the 4.6 sensor signals so that the factory computer thinks that it's still a mod motor. Going to be doing a 36-1 reluctor wheel setup etc... a Megasquirt will be running the show though, the factory ECU will be a dummy in read-only so that I can uplink for DMV inspections. Have to work out the logistics, but it should be doable.
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02-21-2013, 02:55 PM
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Or is the thought that these turbines would be too much lag on this build?
02-23-2013, 03:19 PM
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Well, I called FI the other day, and in talking with them, realized that the twin 76's would run basically the same price as an s400. I would want my existing one to be freshed up and then matched to another that I would buy. By the time I send mine back, pay for the rebuild and then purchase the new one, I'm at the price of a new s400 with a race cover.
Plus, the .96 a/r with a 68 wheel on the 76's wouldn't spool all that great on a street driven car. It would make KILLER boost, but up high enough that there would be no fun stabs on the street.
All of that being said, I've decided to go with a single s400 with a race cover. Maybe a billet wheel if I can swing that. Ultimately, my end goal (once I get my motor built) will be met just as well with the big single. And it should still have some street manners.
PLUS, this leaves me the ability to sell my existing setup off to fund the new turbo and piping.
Plus, the .96 a/r with a 68 wheel on the 76's wouldn't spool all that great on a street driven car. It would make KILLER boost, but up high enough that there would be no fun stabs on the street.
All of that being said, I've decided to go with a single s400 with a race cover. Maybe a billet wheel if I can swing that. Ultimately, my end goal (once I get my motor built) will be met just as well with the big single. And it should still have some street manners.
PLUS, this leaves me the ability to sell my existing setup off to fund the new turbo and piping.
