Help me decide the next step....
Thread Starter
Teching In
Joined: Apr 2013
Posts: 35
Likes: 0
Help me decide the next step.... Well I've come to that fork in the road and I need a little help from the experts, the guys that have been there done that. I've got a 96 GMC c1500, RCSB. My current setup is:
2002 Lq4
243 heads (stock)
Tbss intake/87 mm throttle body
Shoenfeld Long tube headers
.40 Cometics head gasket
XR275hr (222/224 on 112) cam w/918 springs
Comp hardened pushrods
True dual 3" with magnaflow x over
Bosch 0280155868 injectors (40lb @ 58psi)
Walbro 255 fuel pump
Electric fans
Compression is at around 10.6 to 1
Backed by a 4l80e with a transgo hd2 kit, 3200 convertor and 4.10's and an eaton posi. The truck is a lot of fun, runs 12.9's @ 107,on drag radials. It's great on the street, brings decent mileage, but I want more. I'm guessing that it's somewhere around the 380-390 rwhp area, and I thought of putting a bottle on it, but I don't want to be bothered with expensive fills, only having it when the bottles full and around here it's illegal to have a bottle hooked up on the street. Do that pushes me towards FI. I want the truck to run in the low 11 range.
My list of spares parts includes:
A stock 2004 Lq4 from an express van with 120,000 miles
A pair of obx shorty headers
Another tbss intake and 87mm throttle body
The original 3.42 rear gears.
So what I was thinking about doing was pulling the current engine (using it in another project) and building a new one suited to the turbo. I'd like to build this this thing on using the best "budget" parts to get the job done. I've even looked at
ebay turbos, but I don't want to waste my money where I don't have too, which included buying chinese parts that fail over and over. I can do all the fab work, but need to know what's the best way to get 550 or so rwhp with what I have, new or old setup. Sorry for the long winded post, thanks for any help.
2002 Lq4
243 heads (stock)
Tbss intake/87 mm throttle body
Shoenfeld Long tube headers
.40 Cometics head gasket
XR275hr (222/224 on 112) cam w/918 springs
Comp hardened pushrods
True dual 3" with magnaflow x over
Bosch 0280155868 injectors (40lb @ 58psi)
Walbro 255 fuel pump
Electric fans
Compression is at around 10.6 to 1
Backed by a 4l80e with a transgo hd2 kit, 3200 convertor and 4.10's and an eaton posi. The truck is a lot of fun, runs 12.9's @ 107,on drag radials. It's great on the street, brings decent mileage, but I want more. I'm guessing that it's somewhere around the 380-390 rwhp area, and I thought of putting a bottle on it, but I don't want to be bothered with expensive fills, only having it when the bottles full and around here it's illegal to have a bottle hooked up on the street. Do that pushes me towards FI. I want the truck to run in the low 11 range.
My list of spares parts includes:
A stock 2004 Lq4 from an express van with 120,000 miles
A pair of obx shorty headers
Another tbss intake and 87mm throttle body
The original 3.42 rear gears.
So what I was thinking about doing was pulling the current engine (using it in another project) and building a new one suited to the turbo. I'd like to build this this thing on using the best "budget" parts to get the job done. I've even looked at
ebay turbos, but I don't want to waste my money where I don't have too, which included buying chinese parts that fail over and over. I can do all the fab work, but need to know what's the best way to get 550 or so rwhp with what I have, new or old setup. Sorry for the long winded post, thanks for any help. 
TECH Enthusiast
Joined: Jul 2013
Posts: 617
Likes: 0
From: Okmulgee, OK
I would leave the engine that you have in it, maybe gap the rings some. Change the cam, and do valve springs. Use the OBX Shorty Headers you have and flip them, then put a Borg Warner S475 on it. Treadstone Air to Air, some 80lb injectors, and another Walbro 255LPH. Should be good for 10's.
Thread Starter
Teching In
Joined: Apr 2013
Posts: 35
Likes: 0
Wouldn't I be better to just throw the other motor in with the mods you recommend? It's easier to get the work done on the stand before hand and just swap it out. I also figured 10.6:1 isn't as favourable as 9.5:1 for boost. Plus I'd rather not spend money on gaskets, when I could leave my current setup complete and just build the other engine as long as it's better suited.
