galletti

Hi there,
I am a newly registered member here and would like to let you know how informative and helpful this board has been. Even though I just registered I've been logging on and reading for months.
That being said, I have a few questions about a project I'm planning. I am in the process of getting an 88-90 IROC convertible. My plans are to swap in a 4th gen engine and then adding an ATI procharger setup.
I am concerned that factory subframe connectors will get in the way of the swap. Is this the case? If so, what can be done about it?
I understand that there is some grinding that needs to be done for the ls1 swap due to alternator clearance. My question is, will the procharger fit after the ls1 swap? I haven't been able to verify where it would mount but I think there is an issue here.
This is already a long post so I'll stop here. Thanks for the help guys.
Later,
Marcos

Jza

A fair amount of fabrication is going to be required for a motor swap as ambitious as an LS1, and even moreso with an ATI.

That said, it's a matter of solving the issues one by one as they come up. I understand you're trying to get a heads up on potential problems, but it's not something that's going to be common enough to find many answers here. I do hope you find them.

I doubt the factory "bracing" on the convertable will give you many problems with that install. I think the main issues will be the fenderwell clearance, and the front k-member clearance.

When you get to the point you can install this stuff the answers will mostly present themselves.

Good luck with your swap.

galletti

Thanks for the reply. I totally agree. Problems will definitely show up as the project goes along. The specific questions I have arise from the information I've gathered around the web and this tech board.
For example, the Speartech web site has a page dedicated to an ls1 swap they performed in a 91 Z28. The most important mods are as follow are are posted here http://www.speartech.com/coproj-1991ls1.html
-Custom fabricated motor mounts (no big deal)
-Added a piece to make the crossmember reach further back since the new 4L60 tranny was longer than whatever the car had originally (I don't know if this will be an issue with a t56 as I plan on doing. Is the 4L60 longer than the T56?)
-"When installed, the clearance is very close between the alternator output stud and this frame support bracket. A little notch in the frame bracket and all is well." (This is one of my major concerns if I choose to go the LS1 way since I believe the ATI Procharger mounts in the alternator spot and the alternator gets moved up. Would using a Corvette LS1 solve this?)
-"We had clearance problems on the passenger side between the coil pack and the A/C box. For a solution I used a truck coil pack with the round Delphi coils. These mount 1" higher on the valve cover, relieving the congested area!" (Any thoughts on this will be appreciated)
Thanks again. Any help will help me decide on LS1 vs. LT1.

MdFormula350

sounds like quite a project, a ls1 in a thirdgen is a great idea and a sight to see.. also a lt1 with a supercharger is a great idea..

good luck for whatever you choose..

galletti

Thanks. I'll post my progress as it goes.
Just FYI, I did a little more research and I may have answered my own question with a little help from this message board Man, I can't say enough about the people here!!:hail:
I found out that the LS1 Prochargermounts in front of the alternator using extensions on the alternator factory bracket on the lower driver side of the engine. The LT1 Procharger mounts on a bracket that's included in the kit and goes on the lower driver side of the engine as well.
There is still the clearance issue mentioned in my previous post.
Also, according to Z28racer, there may be another clearance issue with the power steering box.
Any info will help. Thanks again.

Jza

I dunno man. Using a kit is bound to cause problems.. I'm wondering about clearance between the blower and the radiator/support because the LS1 in a 4thgen sits halfway under the cowl and you don't have that when it's in a thirdgen.

BTW the 4L60E is the same size as a 700R4.

If it were me, I'd worry about getting the motor installed and working in the car first, then worry about adding the ATI. Most really good fabrication jobs require at least two assembly/disassembly phases anyway, so one-shotting it may make it harder to troubleshoot any potential problems that can and will arise once you get underway.

galletti

You're definitely right. I just want to gather as much info as possible. Thanks for the info on the tranny but I'm planning to go with a t56 not a 700R4. Are they the same?
About the radiator clearance though, I'd have to check. They didn't seem to mention anything about this in the speartech site and, if I'm not mistaken, there's a lot more room between the firewall and radiator on a third gen than on a fourth.
Thanks again for the time and attention.