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1000 RWHP Sky build

50K views 380 replies 29 participants last post by  Robotech 
#1 · (Edited)
I thought I would make this thread to start documenting my 1000 rwhp sky build thread.

I'm starting this build with the following:

-2007 Saturn Sky Redline
-427CI LS7, stock except for the cam, partially filled block, 160# injectors, and forged pistons
-(2) Borg Warner S366 turbos, tial wastegates and BOV's
-Holley EFI w/digital dash
-Twin walbro 450lph in tank pumps
-4L80E w/circle D turbo converter
-Ford 8.8 IRS

I've already run into several issues. The trans tunnel needs quite a bit of manipulation to fit the wide pan rail of the 4L80E but it's possible with some determination. The 6L80E I believe would have been much simpler but to achieve my goal I think I have to run the 4L80E. It has been built from the ground up to handle the power and is easily controlled by the Holley EFI. I'm also installing a corvette steering wheel so I can utilize the paddle shifters.

I'm running the early style CTS-V accessories that hotrod used in their swap and the C6 corvette motor mounts are hitting the passenger side a/c compressor. To fix this I swapped the mounts around so the drivers side is on the passenger side and vise versa. It lands on the motor mount pads nicely even with them being put back a little bit.

I'm a bit stuck right now because the sheet metal valve covers ran into the brake booster. To fix this I'm going to have to go back to a stock style valve cover. Once I install the stock valve covers then the motor will be able to slide back 2-2.5" more until the motor is almost touching the firewall. At that point I can drill the motor mount holes into the crossmember.

Another obvious issue is going to be the header clearance with the ABS module. It looks like it uses some flexible lines so I will be able to move it a few inches which should be enough. I may have to make some new lines if they can't bend far enough for the relocation.
 

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#4 ·
I've decided to ditch the a/c because my idea of switching the motor mounts around isn't going to work... They're off the pad once the motor slides back into the position it needs to be in. The C6 Corvette motor mounts and the CTS-V style a/c system were not designed to work with each other (even though a hotrod.com article suggested it if you wanted to run a/c). I've also had concerns about a condenser blocking airflow to the already small footprint for a radiator to cool the LS7. I will be using a removal smoothline hard top so I guess that will be my a/c.
 
#5 · (Edited)
Here is a video of a V8 Sky for your viewing pleasure. This guy is an engineering genius and he has helped many people tune there cars but, for some reason, he won't help me tune my Sky Redline???:

https://www.youtube.com/watch?t=24&v=2q9BuzNRc3Q
 
#7 ·
Very cool build, but I'm looking to do it a little different. This build won't be as refined as his but I'm confident it will be quicker. I'm familiar with making power and drag racing, now I'm working backward a bit to build a fun streetable car.
 
#6 ·
I believe that is GMTech. He has started posting a little on the site again. He has had some run ins with the mods on the other sites. Over some bad work, supposed less than honest dealings with a site sponsor.

He always seemed like a nice enough guy, and doubt there are very few that his talents. His is a work of art, not only badassed. One of the cleanest builds I have ever seen, going back to the mid 60's. Wish he would come around more often.
 
#8 ·
Why the LS7 if you were going to boost it? Why not a LS3 with thicker cylinder walls. The LS7 is a awesome NA monster. I know you filled it, why not just re-sleeve it? Interesting build non the less. Thanks for posting.
 
#9 ·
I don't think the LS7 is any weaker than an LS3 but I know there have been cases where the top of a sleeve has cracked in the LS7. If I crack a sleeve then I will go ahead and put some darton sleeves in it but for now I'm not worried about it.
 
#10 ·
You will be needing a stout block to get to 1000whp thru a 4lady. Depending on converter choice (how loose you go) you will see 15%-20% drivetrain loss.

A pair of S366 should be enough turbo to make that power. All depends if the engine can handle it!

Holley EFI is a great unit and should be a very tuner friendly ECU for you.

I wish you luck and it looks like a killer build! I hope you keep after it an have it ready for next year. Too many projects get started and put on the back burner.
 
#12 · (Edited)
I was real close to getting an RHS block but decided to just fill the lower half of the stock LS7 block. There are plenty of people in the 1000rwhp territory with them but a little detonation can trash a motor pretty quick. I did swap out the valve guides for bronze and changed out the exhaust valve to an inconel material for turbocharging.

The converter is a stage 4 circle D built for the power, here's a pic:

 
#14 ·
Inconel stands up the heat much better than stainless or stainless/sodium filled. The LS7 also has a history of failed exhaust valves due to poor concentricity with the valve guide and the seat so they had to be reworked anyways. The intake valve is still titanium for weight savings. When I spec'd the cam I went with a comp "LSL" lobe for the intake (average aggressiveness) and a very gentle ramp (LXL) for the exhaust to help out with the weight and the valve opening. High horsepower turbo motors are well known for exhaust valvetrain issues due to the opening cam ramp of the exhaust valve after the compression stroke. There is still a lot of remaining cylinder pressure and the exhaust valve has to work against that exhaust pressure to crack it open. This can bend pushrods, strip the rocker stand right off the head, collapse lifters, etc. A soft exhaust ramp helps alleviate some of those issues.
 
#18 ·
It is used a lot in Industrial Gas Turbines and Aircraft Jet Engines. They use it to make the turbine (hot end) blades.

Yogi
 
#21 ·
No offense at all towards the OP (LT1Pat), but just don't see the need for this type of HP on such a small roadster...
I don't see how in the world you'll be able to get any traction with this big mama up front...
Even with dragster slicks I bet when you floor it, it'll go no where but just smoke the tires right off the rear as you move 2 inches...

Now don't take offense mind ya, I'm all for interesting projects like this one,
but isn't this one over kill?? Never the less I wish very good luck with this project, keep us informed please and prove me wrong...:D:cheers::cool::leaving:

 
#26 ·
I'm friends with one of the first people to do an LS7 conversion in a solstice and he said something very similar to me. When the conversion was done a well known and skilled racer drove it and crashed it on a local highway.

Today I was asking a question to a very reputable local tuner and he's personally known of 6 different 500+hp kappa's and they've all crashed. I may be revising the boost levels I intended to run but I still plan on proceeding as planned with the same components. I'll put 1 psi springs in it and progress from there to find a safe number. I might try 1000rwhp just for fun on a dyno but it seems unrealistic for the street.
 
#22 ·
Oh, trying to put traction down on our cars at anything above 400 whp is a challenge. When I talked to one of the guys that had done an early Mallet conversion he told me anytime he floored it under 60 mph it was nothing but a smoke show.

I had a 450 whp FWD Grand Prix and it was the same way. Having driven that though I can tell you even when you have issues putting the power down, having that kind of power on tap is ADDICTING! You can manage it, you just have to learn how to drive with more finesse when it comes to your right foot. You don't stomp, you roll. You don't mash, you press. You don't gun it, you ease into it.

Plus...V8 sound...yeaaaaaaaaa...I get it. :)

There is a reason though why I'm capping my build at 400 whp. That puts me in 12.0 1/4 mile territory which is a lot of fun on the street without making the car too "stupid fast" to drive daily. LOL
 
#23 ·
IF I wanted that kind of power amigo, I would buy me one those Hennessey corvettes...:D
 
#25 · (Edited)
:leaving: SSShhhhh, me 2...:cheers:

:hijack: Sorry OP for hijacking your thread, now back to your regularly scheduled project, the quest for a 1000whp kappa...:cheers:
 
#29 · (Edited)
I'm finding out that the 4L80E has a lot of complications but I got it to fit. The motor itself could go back another 2" but the bellhousing for the trans is more bulbous than the T56 so it has forced me to sit the motor a little more forward than I would like. I'm moving the battery to the rear of the car to even out the weight distribution a bit.

I can't permanently mount it until tuesday because I need the Holley 4L80E harness from summit. I have to cut a circle in the trans tunnel because the connector is actually going to extend inside of the car slightly. It will be impossible to plug in the harness with the trans in the car. I have to pre-run all the lines to the trans because they're inaccessible once they're up in the tunnel.
 
#30 ·
Glad to see another guy doing an automatic. The 4l60 should fit
I wanted to keep it a little more simple and went with a 700r4. Same basic tranny without electonics.
 

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#31 ·
Did your motor mounts go to the very front of the mounting pad on the crossmember? I thought I might have been the only auto V8 sky because I couldn't find anyone doing this. A manual would have been 10x easier but the auto will be worth it. I love driving manual cars but they just don't work for turbo cars. Mid week the engine will be in its final resting place and I can start working on the fun stuff.
 
#35 ·
I found that the trans harness that I ordered from summit won't be here until Friday so I have to wait until then to install the motor. I made the start of the transmission mount which I'll finish once I drop the motor in. The rear of the tailshaft is so far back that I have to use the tunnel brace bolt holes as part of the mount. I'm going to rivnut in two more nuts to make the trans mount use a total of 6 bolts. The base plate to the trans mount is 3/16 steel which is really heavy, I might drill a bunch holesaws in it to take out some of the weight. I'm also going to weld in supports sort of like an I beam on the sides and front to eliminate any deflection.

I removed the oil pan to weld in two turbo drain bungs which I forgot to do originally. They're -12 Female AN so I can use either a -10 or a -12 drain (-12 if it fits). The drains are lined up with a main cap so they don't get blasted with windage.
 

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#39 ·
I noticed that a lot of people are cutting out the old engine mounting pads and welding in a new set. I'm not sure I see a big point in doing this but I should probably ask - has there been any issues with the stock pads being tweaked? The C6 motor mounts seem to land on them very close to where the stock holes were drilled.

Also, the welding from GM is awful, they should be embarrassed.
 
#40 ·
I noticed that a lot of people are cutting out the old engine mounting pads and welding in a new set. I'm not sure I see a big point in doing this but I should probably ask - has there been any issues with the stock pads being tweaked? The C6 motor mounts seem to land on them very close to where the stock holes were drilled.

Also, the welding from GM is awful, they should be embarrassed.
They welder apprenticeships? :dunno::willy::D:lol:
 
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