LS-1 to LS2/LS3 tuning

[DaddySS]

Planning for the engine refresh, thinking seriously of going with an LS2 or 3. How difficult or tricky is the tuning. I would assume that VE, injectors and MAF would need to be changed for the new volumes, but what about a 2000 PCM handling the rest of the LS2/LS3 hardware - TPS, MAP, Knock, cm, crank position, etc. I know there is a harness for the 58 vs 24 reluctor etc. but is it fairly straighht forward? I have done searches but can't indo specific to the tune.

I finally have the car running the way I want and would hate to start over with trying to solve idle, throttle cracker, throttle follower, etc. issues.

[HSV-GTS-300]

Originally posted by DaddySS
Planning for the engine refresh, thinking seriously of going with an LS2 or 3. How difficult or tricky is the tuning. I would assume that VE, injectors and MAF would need to be changed for the new volumes, Yes. It's not difficult for an experienced tuner.


Originally posted by DaddySS
but what about a 2000 PCM handling the rest of the LS2/LS3 hardware - TPS, MAP, Knock, cm, crank position, etc. I know there is a harness for the 58 vs 24 reluctor etc. but is it fairly straighht forward? I have done searches but can't indo specific to the tune.
There's a converter box to change the signal from 58x to 24x.
I don't know if it also does the 4x to 1x cam signal as well....it probably does.
There's a conversion harness for the 90mm ETB which converts back to earlier 76mm ETB connectors......but if your computer cant work with ETB then TPS will be a problem.
MAP is just an extension cable to run to the front, unless you go LS3 and then the connector also needs to be larger.
Knock sensors, you'll need to use LS1 sensors with LS1 computer.
Drill and tap the Gen4 8mm female threads on the lower block out to 10mm.

Personally I'd change out the 58x and 4x reluctors and run 24x and 1x. I'd also go with a 90mm cable throttle body.
(Weigh the cost of that against 58xsignal converter box and TB harness and Electronic throttle pedal)

[DaddySS]

Thanks for the reply much appreciated. One route I was thinking of going was getting the GMPP LS3 376/480. Do you have any knowledge or experience with the controller that goes with it?
http://www.gmperformanceparts.com/EngineShowcase/index.jsp?engId=LS376480&engine=LS%20376/480&sku=19171224&engCat=ls

[DaddySS]

The march GMHTP has a whole article on the swap to the fourth gen...so with the conversion parts this can be fairly straight forward.:)

[HSV-GTS-300]

No I don't have experience with the signal converter. Seems that if you go with the Hotcam LS3 with converter and harness there shouldn't be too many issues.
You'd just have to specify 4th gen so you'd get what's needed for the ETB, oil pan & front driven accessories.
(Belt spacing on the engine you showed will be as per Corvette)