1970 GTO Version 2.0

[gearbanger]

I am very interested in the hydraulic clutch slave and master. Are you using the Centerforce dual friction clutch? I am wondering what the best setup would be for the pontiac motor, TKO 600 setup? Would keisler be the best place to contact? I saw that McLeod had a setup that some pontiac guys had used.

Since I stepped up to 2" headers, that z-bar has really been in the way!

[andrewb70]

I am very interested in the hydraulic clutch slave and master. Are you using the Centerforce dual friction clutch? I am wondering what the best setup would be for the pontiac motor, TKO 600 setup? Would keisler be the best place to contact? I saw that McLeod had a setup that some pontiac guys had used.

Since I stepped up to 2" headers, that z-bar has really been in the way!

I am using a stock LS7 clutch, but that really makes no difference as far as the hydraulic bearing is concerned. If you are using a TKO 600 I see no reason why you would not go with the complete Keisler setup. Their bearing mounts on a custom transmission front bearing retainer that is included in the kit. I can't really commend as to how well their bearing works, but I can tell you that I am ery pleased with the way the MC works.

Andrew

[gearbanger]

Thanks Andrew, I will check them out. I just went back and reread and realized you have a Richmond. I guess Keisler would have the TKO stuff already scienced out pretty well.

I was wondering what else are you doing to that 6.2 liter to try and get 425 horse at the wheels? That is pretty much z06 performance and it will probably take more that just the ls7 cam to get that out of the 6.2 liter. Are you putting on a blower?

[andrewb70]

Thanks Andrew, I will check them out. I just went back and reread and realized you have a Richmond. I guess Keisler would have the TKO stuff already scienced out pretty well.

I was wondering what else are you doing to that 6.2 liter to try and get 425 horse at the wheels? That is pretty much z06 performance and it will probably take more that just the ls7 cam to get that out of the 6.2 liter. Are you putting on a blower?

I may be silly but I think the LS7 cam and headers will get me to the 420-430 RWHP territory. Stock LS7s put down about 440 rwhp. That is with a TR6060 and IRS. I would bet that my Richmond and 12 bolt robs less HP. I guess time will tell.

I had a LS6 in my RX7 that just had a modest cam. It made right around 400RWHP. This engine has better heads and about 30 more cubic inches. I really think I can get to 420-430 RWHP as is.

Andrew

[andrewb70]

Today I worked on the rear end. I degreased it and gave it a rattle can make over. Along with the cosmetic touch up I installed new upper control arm bushings and finished up the installation of the weight jacks.



If anyone else is using these weight jacks, I would highly recommend painting them. They are steel with a black oxide coating. I already saw signs of surface rust after sitting in the garage for only 2 weeks.





Tomorrow the rear end will get plugged back in and I will start on the wiring. With any luck, the engine will be going in next weekend.

Andrew

[Smock67]

Amazing progress Andrew and some great technical information. I love it

[gearbanger]

I may be silly but I think the LS7 cam and headers will get me to the 420-430 RWHP territory. Stock LS7s put down about 440 rwhp. That is with a TR6060 and IRS. I would bet that my Richmond and 12 bolt robs less HP. I guess time will tell.

I had a LS6 in my RX7 that just had a modest cam. It made right around 400RWHP. This engine has better heads and about 30 more cubic inches. I really think I can get to 420-430 RWHP as is.

Andrew

Maybe on that same dyno you can

The LS7 has 50 more cubes and all kinds of exotic parts like titanium rods and valves, bigger ports, dry sump oiling. It is hard to beleive you can just put the cam and intake on the 6.2 liter and be that close. I hope you are though, then I would really be impressed with the ls2 motor.

If the zo6 makes 440 rwhp, that is only like 13% loss. That seems pretty low.

[andrewb70]

Maybe on that same dyno you can

The LS7 has 50 more cubes and all kinds of exotic parts like titanium rods and valves, bigger ports, dry sump oiling. It is hard to beleive you can just put the cam and intake on the 6.2 liter and be that close. I hope you are though, then I would really be impressed with the ls2 motor.

If the zo6 makes 440 rwhp, that is only like 13% loss. That seems pretty low.

I am not sure what you mean by "same dyno." I ran the RX7 at the drag strip dozens of times. My race weight was about 3000 pounds and I routinely trapped over 125 mph. Punch that into any drag racing calculator and you get about 460 hp. Certainly jives with the chassis dyno numbers.

As for the ls7s, the 505 hp is way underrated. GM Performance parts will be selling a 480 HP version of the LS3 shortly. It is basically an LS3 with the old "hot cam." Its a very mild cam, with more duration but less lift than the LS7 cam. I don't see why my combo would be too far off from that number.

I never really bought into using a percentage to go from flywheel HP to RWHP. It doesn't make sense to me why when an engine makes more power all of a sudden it takes more to drive the drivetrain. I think its more accurate to determine that a particular transmission in a given chassis looses to driveline losses and use that figure. In the end its all academic. The drag strip doesn't lie.

Andrew

[trapin]

"Strip don't lie"

Andrew I think that's your new motto.

[gearbanger]

I guess chassis dynoers have just used data from so many cars that they have come to see the loss work more on a percentage of the total. It makes sense to me that the harder the load is on driveline, the greater the friction would be and thus the more loss you would see.

I do like the new motto idea, "Project Strip Don't Lie"

[parsonsj]

Well, strippers may not lie, but they sure use up your dollar bills in a hurry.



Anyway, Andrew, keep the tech coming. Great stuff!

jp

[David Sloan]

Well, strippers may not lie, but they sure use up your dollar bills in a hurry.



Anyway, Andrew, keep the tech coming. Great stuff!

jp

Ant that the truth!

Its good to see you working on her again!Andrew

[andrewb70]

The rear end is back in the car and the spring adjusters work great. Here is what the spring looks like at the new ride height.



The old ride height was 28" to the top of the wheel well opening. The new rise height is 26". This is as low as I am going to go. As you can see there is not much room between the axle tubes and the exhaust. The 2" drop makes a huge impact in terms of looks. I have tall, 28", tires and now they are tucked up inside the wheel well.

Andrew

[Young Gun]

cant wait to see how this looks! progress has been awsome so far!

[jackfrost]

Andrew, I'm a little confused. it looks like adjusters add a couple inches of height, even if they're all the way down... did you use a much shorter spring to allow for a 2" drop after the height of the adjuster was added?

thanks.

[andrewb70]

Andrew, I'm a little confused. it looks like adjusters add a couple inches of height, even if they're all the way down... did you use a much shorter spring to allow for a 2" drop after the height of the adjuster was added?

thanks.

I used a much shorter spring to compensate for the height added by the adjusters. I am using 175lb/inch springs that have a 9.5" free standing height.

I also found some dyno numbers for a stock LS3 Corvette.

http://forums.corvetteforum.com/show....php?t=1749988

I see no reason why my combo should not make my goal of 430 RWHP.

Andrew

[gearbanger]

If it sounds too good to be true, it probably is. I like how that one guy asked, "was that a dynojet dyno?

Bench racing is bench racing. Drag strip numbers are deceiving too. The setup of the car controls how close you run to those generic calculators. How much of that power you are actually using depends on how well you hook, and all that.

Stick that motor on a real (DTS) dyno before you drop it in the car. It's the best money you can spend. I've heard plenty of stories of picking up over 100 horsepower on the dyno with tuning. 500 bucks for some dyno time is well worth a possible 100 hp.

[andrewb70]

Bench racing is bench racing. Drag strip numbers are deceiving too. The setup of the car controls how close you run to those generic calculators. How much of that power you are actually using depends on how well you hook, and all that.

Actually the setup of the car has very little to do with the trap speed. Using the weight of the car and the trap speed is a very accurate way to determine the power that the engine makes.

If you want to make a statement, just say it. What's your point?

Andrew

[andrewb70]

It is amazing what difference 2" in ride height makes. The rear seems to sit so much lower now. I am sure part of this is due to the fact that I have tall tires and now they looked tucked inside the wheel well.



Andrew

[parsonsj]

Wow, Andrew! Stance looks good.

On the other hand, your color balance is off. Look at the difference in color between this pic and your signature.



jp