Rear unibody prepped for reinforcement plate welding


Subframe reinforcement plates installed.



More pics tomorrow

 

I am so glad you got those done. It was just frustrating observing.

 

Nice... I was wondering where exactly the rear needed to be beefed up. Have heard that's a weak spot in the Bimmers when you start running more power through them.

 

FWIW the intake lift is .613 and Exhaust is .620. Not that it means much but the duration is @.050 227 Intake and 235 Exhaust. My pistons do have valve reliefs in them and I've been told the valvetrain is up to the task. Should be interesting. Got the heads back from the machine shop today. Impressive work. Beautiful surface finish on the deck and nice cuts on the valve seats. These are late model ls1 corvette heads don't know the casting number off the top of my head. Gregories machine did the work, the pictures don't do them justice. I was really impressed with the work

 

If you orient the head as it would go on the passenger side of the motor the head casting number is on the right front side of the head. If they're the later style LS1 heads they're probably 241s. The LS6 heads are 243s.

With that much lift just make sure you use the right springs and make sure the car is up to temp before you flog on it. For me that always meant 150 degrees oil temp before going WOT or over 3000 rpms. You'll probably want to replace your springs every season depending on use. For a street car the recommendation for something like a comp 921 was every 15,000 miles give or take a few thousand.

 

Replacing the springs sounds like a solid preventative maintenance strategy. I like it. I've always warmed cars up before I go WOT, that's good advice. My grandfather taught me that before I could even drive, never forgot it. I'll find out what casting number the heads are tonight.

 

I know some were asking about the gear ratios and top speed etc. etc. Here are some numbers



Trans gearing, 2.40, 1.65, 1.27, 1.00 with 3:15 rear end and 7000 rpm limiter.

1st Gear 2.40:1 68.98 MPH
2nd Gear 1.65:1 100.33 MPH
3rd Gear 1.27:1 130.35 MPH
4th Gear 1.00:1 165.54 MPH

 

So I worked on the car a little tonight. I was trying to press in my solid bushings but I left one of them a little tight I was worried about cracking the housing so I decided to press it back out. The only problem I had was I didn't have a drift/socket big enough to press the bushing out so I had to improvise. Even though it looks crude, it only took 3 min to make and it worked great. The other pictures are of the reinforcements I made to the cover, I created a small crack when trying to install the bushings the first time around so I decided to not only grind out and repair the crack but to go ahead and reinforce both wings and add some lateral bracing as well for good measure since this will be seeing twice the stock hp. I cut some plates at the shop and got Scott to weld them on this afternoon. The lateral braces will add a small amount of additional surface area to aid in cooling. It's probably a negligible amount though. More bushings tomorrow, I'll be glad when these are done

 

Got the rear trailing arm bushings installed today and welded the RTAB reinforcement plates in as well. The rear subframe and diff are ready to go back in the car, i'm just waiting on brake lines. I should be relocating the car sometime in the next 10 days so the engine can be installed. Driveshaft should be done in the next weed or so as well.

Rosette welded RTAB reinforcement plates


Rear subframe

 

First I'd like to say awesome build man. Wish I has the time and finances to do such a project.


My buddy pointed me in the direction of this thread because you were so happy with the work at Gregory's. I'm glad you liked it, makes me feel good to personally hear(see) the great feedback. I don't remember any specifics about these heads. But I remember working on some ls1s recently, and that 7 is my handwriting, I'm the only one at the shop that writes them that way. Thanks for the great comments.