My 05 GT, GT500 swap build thread

[Wlkn Tal]

Got the 4.0L on, and dyno'd it.

The plan was to put this on now before building the motor so I could compare it directly to the 2.9L with no other changes. Everything is the same as with the 2.9. Same tune, same dyno, same everything except the blower itself.

Unfortunately, I didn't have a large enough pulley to keep the boost down to 23-24lbs as with the 2.9L, so it is making about 1.5-2 lbs more boost than before. With that considered, the difference is still very dramatic. It feels like a very different car.

It made 874/800 at the wheels on 25lbs (15% lower + 3.5" upper), 19 degrees timing, and 100 octane + torco, stock motor. The biggest gain was the torque all through the RPM band, which is exactly what I was looking for. I always felt the 2.9L didn't quite make the torque I wanted it to. So I gained 50rwh and 111rwt with just the blower swap.

Next up is a built motor and nasty custom cams. I'm expecting another 80-120rwh from the cams and higher RPM capability.

Here is the graph showing the 2.9L numbers (in green) and the new 4.0L numbers:

I'm amazed it didn't window, I've seen a few come apart at 800 hp

 

[19COBRA93]

I'm amazed it didn't window, I've seen a few come apart at 800 hp

I've seen a couple break, but I think there were contributing factors (tune). I've seen many more actually make over 900hp and hold together just fine. I had confidence in mine holding, so I went for it. However, I did record the dyno pulls for the sole purpose of having some good vids of it blowing up just in case.

 

[05stroker]

Well the tear down has begun. Got the motor out last night. Should have the rotating assembly to the machine shop tomorrow. Hoping to start putting it back together by the weekend. It's getting Billet rods, custom cams, springs/retainers, a '13 GT500 oil pan, and billet steel oil pump gears.

Where does the power steering pump mount on those motors? I would love to have my alt. there on my 4.6.

 

[Nitemare]

What fuel system are you running with your setup

 

[19COBRA93]

Where does the power steering pump mount on those motors? I would love to have my alt. there on my 4.6.

It mounts right on the top front of the timing cover. You can just see it here under the coolant hoses.

What fuel system are you running with your setup

It's pretty basic. ID1000 injectors and a dual BAP. The rest is stock GT500 stuff.

 

[5iv]

Awesome build. Hopefully I'll have the knowledge/balls to do this someday. Those harnesses look scary from your first post! Lol

 

[jays86lx]

Amazing build. I found some deals on complete GT500 drivetrain and thought about doing this. After reading this whole thread I believe its time to save up. Excellent Job.

 

[05stroker]

It mounts right on the top front of the timing cover. You can just see it here under the coolant hoses.

.

Thanks!

 

[19COBRA93]

Update. The motor is going back in tomorrow. The rods, cams, '13 oil pan, and all ARP hardware are all in and the engine is assembled. I built the K-member spacers last night, and the K-member is going in tonight. Tomorrow the engine comes off the stand, then I'll bolt up the trans, and drop the whole thing in and hopefully get it all buttoned up and started this weekend.

A few pics along the way:

Rods/pistons assembled:





K-member and 1/2" spacers:





'13 GT500 oil pan assembly:





Engine complete:

 

[Scott]

Looking good! Best of luck with the install!

 

[BruceH]

Those rods aren't going to give. What's the piston dish?

 

[skwerl]

I must have missed it- Why are you putting spacers under the K member mounts? Is the blower hitting the hood?

 

[GallopingFord]

I'm guessing it's for added clearance to keep the stock gt500 hood and he's already maxed the engine mount lowering... Makes me think about doing this to add more clearance on my Bullitt... That's a terrific idea

Sam how'd you do it? Any write up or specific place to get the spacers?

As always, looks great, and that new engine sounds spectacular.

 

[19COBRA93]

Those rods aren't going to give. What's the piston dish?

12.5cc I believe. They're the stock GT500 Mahle 8.4:1 forged pistons. I considered new pistons and raising the compression up to 9:1, but I've got a blower now that will make all the boost I want, and these pistons are proven already, so I stuck with them to keep within my budget.

I must have missed it- Why are you putting spacers under the K member mounts? Is the blower hitting the hood?

Yes, the 4.0L Whipple is huge, and doesn't fit under the stock hood -by a long shot. The BMR K-member I have has 1/2 lowering motor mounts which are not quite enough, so I added the 1/2" spacers to solidify my hood clearance.

I'm guessing it's for added clearance to keep the stock gt500 hood and he's already maxed the engine mount lowering... Makes me think about doing this to add more clearance on my Bullitt... That's a terrific idea

Sam how'd you do it? Any write up or specific place to get the spacers?

I bought some 1/2 aluminum stock from a local guy. Then measured where they needed to be, cut them with my band saw, drilled them out with my drill press, and voila!. It was actually quite simple. I haven't addressed whether I need longer bolts yet though. I'll cross that bridge when I get to it (in the morning).

 

[GallopingFord]

Wow, that is a very neat...

I'm curious to how that could affect a ground clearance, and alignment/spring height/etc as the lower control arm is now sitting 1/2" lower.

I'll keep my eye on this for sure. Thanks!

 

[19COBRA93]

Wow, that is a very neat...

I'm curious to how that could affect a ground clearance, and alignment/spring height/etc as the lower control arm is now sitting 1/2" lower.

I'll keep my eye on this for sure. Thanks!

It effects the springs for sure, but I have coilovers, so I can adjust for it. Ground clearance shouldn't be too bad. I had plenty before, so I'm hoping for no real problems. Alignment will need to be altered. It's not an ideal setup, for suspension geometry, but I think it will be fine for what I do.

 

[Department Of Boost]

It effects the springs for sure, but I have coilovers, so I can adjust for it. Ground clearance shouldn't be too bad. I had plenty before, so I'm hoping for no real problems. Alignment will need to be altered. It's not an ideal setup, for suspension geometry, but I think it will be fine for what I do.

If you run the taller ball joints like the Steeda X5's it will get your geometry back to stock.

 

[RetroGT2006]

Wow, one day I hope I can do something like this to mine..

 

[19COBRA93]

It runs!

Short vid of just after startup. I only let it idle for a minute, as it still doesn't have coolant in it. So it's idling a little high. Once it idles down, the cams will be much more noticeable. I wanted to start it up before completely finishing it in case there was a problem and I had to tear it all apart again. It's great though, so I'll be finishing up the little stuff in the next couple days.

Click on pic:

 

[GallopingFord]

Music to my ears! Nice work. Anything special with the oil for breaking in?