Thread: 2004 GT Top Swap (Lots of Pictures)

boost bypass valve....

Originally Posted by nascartech

just get a full l32 top lim heads s/c map rail and injectors harmonic balancer and ideler pully reason i say l32 s/c is because it is more efficient and easier to put ur tb on to

I know it is more efficient, but I am not really going to be pushing the blower to it limits by any means. I have no interest in that. Also just because it is easier to put my TB on is no reason to go withe the Gen V blower. If I can't do this for >$500 I'm not doing it. But I can get the L67 heads, valve covers, all the pullies, belt tensioner, harmonic balancer, LIM, Gen III blower, and all the sensors I want off a running 98 Grand prix gtp for $250... That REALLY helps me reach my goal of less than $500 for a top swap. I still have a couple things to figure out like which company can actually tune for me and if they are going to give me a GTP PCM or just tune my PCM. This really isn't that hard or expensive though, and I'm here to prove it. I will have a 100% DETAILED walk through of a Gen III (L67) top swap on a 2004+ Grand Prix when I am done.

Originally Posted by Storm

I know it is more efficient, but I am not really going to be pushing the blower to it limits by any means. I have no interest in that. Also just because it is easier to put my TB on is no reason to go withe the Gen V blower. If I can't do this for >$500 I'm not doing it. But I can get the L67 heads, valve covers, all the pullies, belt tensioner, harmonic balancer, LIM, Gen III blower, and all the sensors I want off a running 98 Grand prix gtp for $250... That REALLY helps me reach my goal of less than $500 for a top swap. I still have a couple things to figure out like which company can actually tune for me and if they are going to give me a GTP PCM or just tune my PCM. This really isn't that hard or expensive though, and I'm here to prove it. I will have a 100% DETAILED walk through of a Gen III (L67) top swap on a 2004+ Grand Prix when I am done.

buy a tuner and learn to tune it yourself.

A tuner alone costs $500 my whole swap is going to be less

but it will be the best thing youll ever buy for your car and if you disagree with that then you have no idea what youre getting yourself into.

I understand where you guys are coming from telling me to get my own tuner. I might do that in the future once I get things up and running first.

Originally Posted by matt5112

barometer measures pressure, thats what the MAP sensor does. MAP means Manifold Absolute Pressure.

You dont need to hook up the BBV (Blow by valve) solenoid as long as you turn traction control off every single time you turn the car off. If you do not wish to disable traction control all the time, then you need to hook up the BBV solenoid.

Please can someone explain this better! Will my car not run worth a **** if I have it hooked up? From what I understand this device opens and closes to control boost. I don't need traction control and I don't know if I want to wire in the BBV. ANYONE?

I'd wire in the BBV. That's just me though. The car should run okay, but I don't know that it'll unload ergo possibly killing gas mileage. But I'm not 100% on that.

Originally Posted by GeosGP

I'd wire in the BBV. That's just me though. The car should run okay, but I don't know that it'll unload ergo possibly killing gas mileage. But I'm not 100% on that.

What do you mean it won't unload ergo? ERGO?

What is the purpose of the BBV, obviously is bypasses boost, but why?

Originally Posted by Storm

What do you mean it won't unload ergo? ERGO?

What is the purpose of the BBV, obviously is bypasses boost, but why?

Ergo... I mean 'therefore'.

You don't always want it to be pushing boost. Like when you are cruising down the highway at 70, you don't need boost. BBV to the rescue.

Originally Posted by GeosGP

Ergo... I mean 'therefore'.

You don't always want it to be pushing boost. Like when you are cruising down the highway at 70, you don't need boost. BBV to the rescue.

lol ahhhh ERGO, I was thinking it was some car term I hadn't heard or some internet slang.

See to wire in the BBV I have to wire it up to a power source and than to the PCM I believe which another member on here is helping me with since he has gone through the process.

Still gathering information. Won't start the build till I am certain I can go start to finish completely.

Ah, I see. Shouldn't be too difficult to wire up. And don't rush it; you should spend more time planning this than actually doing it.

You want the BBV functional, but wiring it for computer control is a totally different issue. You only need to wire it up if you want the computer to be able to dump boost for things like traction control, speed limiting, etc. What Matt was saying is that if you leave it off, you need to have the computer set up to not pull fuel for those things, either.

So what makes the BBV functional is having a vaccum line hooked up to it? Your saying I will want it to be functional, but I don't have to wire it up to a computer to have it be functional? I was under the impression that to have it working at all you would NEED to have it wired up to the computer so it knew when to open and when to stay closed.

I am going with a Gen III blower for sure now. Here is a BIG question I have.

1. Do I NEED the baro sensor? (same as map sensor)
-If so does it have to be from a 04+ GTP or does it have to be from an L67 engine? Since I am doing a L67 top swap I am assuming I need to get the L67 MAP sensor, could be wrong.

it opens and closes based on vacuum 95% of the time, but the computer can command it to open to dump boost under conditions like traction control.

YES, you need the MAP sensor.

Originally Posted by Bio248

it opens and closes based on vacuum 95% of the time, but the computer can command it to open to dump boost under conditions like traction control.

YES, you need the MAP sensor.

Ahhhh, lol I know I need a MAP sensor... but 04+ GTPs have a MAP and a BARO sensor. They are the EXACT SAME sensor. For the MAP sensor do I need the L67 or L32 MAP sensor?

For the BARO sensor do I need the L67 or L32 sensor?

Remember I am going with a L67 top swap with the Gen III blower not the Gen V.

Originally Posted by Storm

1. Do I NEED the baro sensor? (same as map sensor)
-If so does it have to be from a 04+ GTP or does it have to be from an L67 engine? Since I am doing a L67 top swap I am assuming I need to get the L67 MAP sensor, could be wrong.

I've said before I don't work on 04+ much, so take this for what it's worth; the computer uses baro readings for various calculations, so yes, you need the baro sensor as well as the standard MAP sensor in an 04+ L32 tune. The sensors are different on the L67 vs L32, but I'm not sure why. Just get the L32 sensors and be done with it. Wiring is going to be another issue, though.

Originally Posted by Scimmia

I've said before I don't work on 04+ much, so take this for what it's worth; the computer uses baro readings for various calculations, so yes, you need the baro sensor as well as the standard MAP sensor in an 04+ L32 tune. The sensors are different on the L67 vs L32, but I'm not sure why. Just get the L32 sensors and be done with it. Wiring is going to be another issue, though.

Well this is going to be fun. I dont think anyone has done a L67 swap on a L26.

Originally Posted by Storm

Well this is going to be fun. I dont think anyone has done a L67 swap on a L26.

I'm sure some folks have done it, they just haven't posted up about it.