🔧 BUILD Upside-down M90 GTP build thread

General Information

When your wife gives you permission to build a racecar, you build a racecar.

This is what happened to me. However, all funding for this project comes out of my construction account. I really need a telehandler, so this is very budget friendly. Luckily, I've been stockpiling parts for years. This isn't an overnight build by any means. My goal is to make a 1/4 mile pass with it before the tracks close for the season. I'm taking a risk here and using photobucket for image hosting, so hopefully they don't screw me over again.

So let's start it off. I bought a 04 L26 motor with somewhere north of 100k on it and started to tear it down.

1689132772823.png












Everything looks good so far. The pistons are really clean. There was some junk sitting in the oil pan, but not much.

GTPpower

TCG Elite Member
Jun 5, 2012
6,294
9,609
Nebraska
Just catching up on this build so I don't know if it's been mentioned yet, looks like you're doing the same intercooler setup a lot of aussies do just a little better I think.


I've been following a few of their pages on facebook and from what little information I've gathered they've seen drops in boost pressure from running their a2a intercooler deal. Seems to be a really common mod down under for intercooling though.

Yeah that's definitely the way to go as the standard heater core plate everyone else uses can't touch the big intercoolers.

I was going to just use that mace plate, but I was trying to build an intercooler system the fbody guys could use too. It ended up not working, but at least it's a cool story.
 
  • Like
Reactions: v6buicks

v6buicks

TCG Elite Member
TCG Premium
Oct 22, 2018
6,258
15,450
Franklin, IN
Real Name
Jon
Yeah that's definitely the way to go as the standard heater core plate everyone else uses can't touch the big intercoolers.

I was going to just use that mace plate, but I was trying to build an intercooler system the fbody guys could use too. It ended up not working, but at least it's a cool story.
I think the biggest problem with F-bodies and SC intercoolers is cowl clearance. I can't imagine there are many ways around this without a tubular k-member or cowl delete. I think there are very few people able/willing to do the top swap anymore let alone make the clearance for an IC. I'm not even sure that I'm willing to go that far on my car. It's too much of a rusty pile. Lol
 

Mr_Roboto

Doing the jobs nobody wants to
TCG Premium
Feb 4, 2012
25,639
30,504
Nashotah, Wisconsin (AKA not Illinois)
I think overall I'd rather shoot alky into the supercharger honestly. I guess you could make a lifter valley pan and work some magic that way too now that I've said it. The OHC Fords were a lot better set up to intercool because they don't have oil or push rods down there to take up space. That is a full custom lower intake though.
 

Mr_Roboto

Doing the jobs nobody wants to
TCG Premium
Feb 4, 2012
25,639
30,504
Nashotah, Wisconsin (AKA not Illinois)
Yeah, I was going to build an entire new lower intake so I could sink the blower way down into it, but then I decided that I would like to enjoy the car before I turn 80.

I do think I'm going to cut out the bypass valve or weld it shut, and then put on an actual blowoff valve. Should make for some cool noises.

Build it in parallel. May as well be prepared for the next iteration.
 

GTPpower

TCG Elite Member
Jun 5, 2012
6,294
9,609
Nebraska
Build it in parallel. May as well be prepared for the next iteration.

I would, but I'm not sure how to route that without a turbo feeding into the blower. I might just do a regular vent to atmosphere for now, them change it up to a recirc style once I twincharge the car. I would still need the regular bov anyways with the turbo. I would probably have to use a couple recirc bov's to keep it from compounding.
 

GTPpower

TCG Elite Member
Jun 5, 2012
6,294
9,609
Nebraska
A friend of mine owns a Dyno and is having a Dyno day on June 28th. So I'm going to try and fix a few things before then.

First, that deadend 90° before everyone loses their mind again.

IMG_20200618_180108551.jpg

I'm going to do more welding and try to get rid of some of the couplers to eliminate any boost leaks.

Got some new hood pins for better adjustability.

IMG_20200618_175644611.jpg


And, more ricer mods.

IMG_20200618_175636920.jpg

IMG_20200618_174956223.jpg

I'm going to ditch the factory bbv, and use this bov to do it's job, just to eliminate that as a boost leak problem. Plus it should sound cool on a m90 car.
 

GTPpower

TCG Elite Member
Jun 5, 2012
6,294
9,609
Nebraska
I fixed the pipe just for you Yaj Yak Yaj Yak .

IMG_20200627_162510876.jpg

Did some other cleaning up of the pipes and couplers. Didn't have time to install the bov though. But, to the Dyno tomorrow we go. It's nowhere close to where I'd like it yet, but very slowly making progress. I'd be pretty happy with 400whp, but I'm guessing it's more like 350.
 

v6buicks

TCG Elite Member
TCG Premium
Oct 22, 2018
6,258
15,450
Franklin, IN
Real Name
Jon
I was more just saying that it's going to suck being inside his shop when it's that hot.
I was really shocked at how well we managed yesterday. Brian's fans did some serious work because I didn't start sweating until I was loading up on the trailer. I didn't even sweat while changing plugs in my egg frying hot engine. Lol
 
  • Like
Reactions: GTPpower

Yaj Yak

Gladys
TCG Premium
May 24, 2007
122,148
87,662
Niche score of 2,363
I fixed the pipe just for you Yaj Yak Yaj Yak .

View attachment 61433

Did some other cleaning up of the pipes and couplers. Didn't have time to install the bov though. But, to the Dyno tomorrow we go. It's nowhere close to where I'd like it yet, but very slowly making progress. I'd be pretty happy with 400whp, but I'm guessing it's more like 350.
I feel better
 

GTPpower

TCG Elite Member
Jun 5, 2012
6,294
9,609
Nebraska
I remember when my reluctor wheel came loose on my GTP and the trans was acting a fool, Trannyman told me to unplug the wiring connector and the trans would default in 3rd gear and just stay in that gear until I could get home. IDK if you want to try that to see if you can get 3rd gear back?


I welded the reluctor wheel on, so that shouldn't be the problem. The car has never had 3rd gear. I'm not sure what would happen if I unplugged it. Maybe just neutral or still 2nd.
 

GTPpower

TCG Elite Member
Jun 5, 2012
6,294
9,609
Nebraska
Fucking trans issues. Same reason alot of peoplenleft that platform.

Man I hope its something simple or do you have another trans ready or parts to rebuilt this one?

I don't. It definitely needs to come out. It shouldn't need much for parts though. Most likely just a couple seals are causing my problems.
 
  • Like
Reactions: Rent Free

Thread Info