Hello everyone, I am in the process of aquiring a '05 XLR. I am interested in converting the 5 speed auto the the newer 6 speed. I have the transmission but I was wondering if anyone here could shead a bit of insight on the computer controls. I am very proficiant in the way a C5 corvette controls everything but the XLR ( and C6 corvette for that matter) is a bit forighn to me. Could this be a plug and play situation? Does anyone know if the wiring harness is the same or close to the same? Also is there any fetures that the six speed has over the 5 speed. From what I have seen GM really does not like to desighn new parts so I am going out on a limb here but I think this could be a fairly simple swap.

Too give a bit of background here, I am going to try to get one of these cars in the the 9 second quarter mile range and still have all the amenities of a luxury car. I really only have three major requestes for the car, that is that it is Black and that it is a six speed auto, and that it is NOT a V. The plan is a twin turbo set up along with some motor work. I have aquired a drivetrain from a 2007 XLR to use as a motor to R&D with long with the 6 spped auto to use.

I have done quite a bit or reading on here and this seams to be a great place to read. I look forward to many great converstaions on here and the results on exactly how far we can push a northstar engine. :yesnod

sounds like a great project, I hope you'll keep us informed on your progress!

Does anyone know how nuch torque the 6 speed trans can handle. The z vette only comes in std shift. Does that mean that GM worries about 505HP strain on the 6 speed auto? I am at about 520-530 estimated at crank based on RWHP of 407. I have been worriied/wondering if the trans can handle the added 80 plus HP.

It's probably doable to do this swap, but it's going to require some minor rewiring of the car. The 5-speed has a separate transmission control module which is attached to the same bracket as the engine control module. The 6-speed has the control module all integrated into the transmission. The 5-speed has a 20-pin wiring connector, the 6-speed has a 16 pin wiring connector. So basically you would have to replace the connector at the transmission and pass through the wires from the existing TCM harness right to the transmission (power, ground, ignition, GMLan, etc..) The existing TCM for the 5-speed would then be removed.

Does anyone know how nuch torque the 6 speed trans can handle. The z vette only comes in std shift. Does that mean that GM worries about 505HP strain on the 6 speed auto? I am at about 520-530 estimated at crank based on RWHP of 407. I have been worriied/wondering if the trans can handle the added 80 plus HP.

Given the way that the 4l80e handled power I am going to say that this trans will be up to the task, of course in stock form there is only so much power and abuse it can take. I am debating on trying to make a few improvements to mine while it is out. I really hate to do things twice.

It's probably doable to do this swap, but it's going to require some minor rewiring of the car. The 5-speed has a separate transmission control module which is attached to the same bracket as the engine control module. The 6-speed has the control module all integrated into the transmission. The 5-speed has a 20-pin wiring connector, the 6-speed has a 16 pin wiring connector. So basically you would have to replace the connector at the transmission and pass through the wires from the existing TCM harness right to the transmission (power, ground, ignition, GMLan, etc..) The existing TCM for the 5-speed would then be removed.

That is exactly what what I needed to know, Thanks man. This seams like it is going to be a fairly simple swap. Now I am just going to have to try and make it look stock so they don't void my warenty, HAHAHA:glol

That is exactly what what I needed to know, Thanks man. This seams like it is going to be a fairly simple swap. Now I am just going to have to try and make it look stock so they don't void my warenty, HAHAHA:glol

Well, I don't think you're going to get past the warranty issue. However if you still do it anyways under warranty, they just won't cover the transmission and any related components that you modified.