ls1 throttle body conversion?

[JUSTA3.8V6]

this is my first post and i was wondering how hard it would be to convert to an ls1 throttle body for my 87 gn? i am having a upper manifold custom made but dont want to spend an arm and a leg on a throttle body. just wondering if i can use the TPS off the ls1 TB? ive got quite a few plans for spring and am just throwing ideas around

 

[blackgn1]

Why the custom intake? That seems expensive to me. What are your goals? You can run in the 10's with a stock intake and throttle body. I'm just trying to put a finger on your build.

 

[JUSTA3.8V6]

the custom upper will cost me next to nothing. i plan on an rjc power plate to go along w it. the reasoning for the ls1 throttle body is because i am doing a 3'' IC and piping and dont really want a bottleneck at the throttle body. my car puts down 371hp and 461ftlbs @ the wheels right now. hoping for around 450 @ the wheels

 

[Scott Atk]

You can't put an RJC power plate on a custom plenum (upper intake). They are specifically designed to fit specific plenums.

 

[larrym]

yeah the power plate is to even out flow to all cylinders with a stock plenum you could end up with 1 or 2 lean cylinders using it on a different application

 

[forcefed3.8's]

I know of a car with a stock TB running 9.17@152. If you want the look of the 3", go with a 70mm TB, they are 3". What you are looking to do will net 0 gains.

 

[DCVING 6]

You could just buy this:

FULL THROTTLE SPEED - 70 MM BILLET THROTTLE BODY

 

[blackgn1]

You are going to have alot of issues to deal with going to a custom upper and throttle. Heck.....you'll have issues with a stock car unless you are extremely familiar with turbo buicks.

 

[TurboTnZ06]

450 at the wheels only needs the stock tb and doghouse. I used the stock tb to put down 500+ hp and almost 700 ftlbs tq on my old iron headed 235 inch.

 

[JUSTA3.8V6]

i understand what the RJC plate is for. the custom doghouse will be the same size as stock, just will have an LS1 TB bolt pattern, only if its possible. i can pick up an LS1 throttle body for around 50$. that one on full throttle is 300$. Work has been slow and im on a tight budget.

 

[DCVING 6]

If your on a budget why not stay with the stock plenum and tb? As many have said, even though they look small, ported stockers can put up some BIG numbers.

With the LS1 unit, what are you going to do about the TPS, IAC, vacuum block?

 

[JUSTA3.8V6]

those are the Q's i was asking in the first place. i have not got an answer about that. maybe i will just have to port the stock stuff and get a reducer. i just didnt want a bottleneck at the throttle body since i am going with 3'' I/C piping. it was just an idea since i can get an ls1 TB really cheap and a friend makes cusom mani's

 

[DCVING 6]

Yeah I think you'd run into more trouble than it is worth getting the electronics to work correctly.

At least where it necks down to 2.5" at the TB doesn't hurt the performance any.

Here is mine, yea it would look better at 3" I guess, but could be worse.

 

[Mike E]

I'm pretty sure LS1 TB's take 4" plumbing and the throttle bracket will take some modifying.

Another option, but not any cheaper is using a mustang 70mm TB. I'm using one on my car because I already have it. The buick IAC can be adapted and the mustang TPS only needs a connector change. The throttle linkage will also need to be modified.

 

[Pronto]

LS1 conversion= a total waste of time and money for your goals. Theres nothing to be gained at that hp.

 

[larrym]

LS1 conversion= a total waste of time and money for your goals. Theres nothing to be gained at that hp.

"yeah but it looks bad ass"

 

[JUSTA3.8V6]

thx mike, ill check that out