I just spoke to a local shop that does dyno tuning (chassis/engine) they do alot of aftermarket EFI and LS1 stuff. I asked them if they did LT1 and they said they did awhile back but not anymore (they used LT1 edit). They told me that they found the LT1's would not hold a tune in the computer. They could change it, but would not save it (especially OBD1s). They now put aftermarket systems in modded N/A cars or blown/turbo. Has anyone ever heard of this? I have a PCM for less tune and it always seemed to run good after it was tuned. Never seemed to return back to stock.

 

Sounds to me like the are trying to sell expensive aftermarket systems.

 

Sounds like to me. There would not be all these people (me included) tuning their cars if it did not "hold".

 

II think they are largely incorrect.

 

Let's move this to the "Computer Diagnostics and Tuning" forum, and see what folks there have to say.

 

I would not go back to that shop.....

 

Sheesh, at least let me get my rubber boots on if you're going to throw around that much bs.

 

Thats what I thought. I only have bolt ons, but am going to do cam, heads 383 in the future. I did alot of research after I bought the car, so I was in disbelief. The funny thing is they are a reputable shop that has done tons of tunes. They did our heads on our racecar as well. They convinced a guy I went to school with to put a fast system on his blown street 94 Z28. They said LS1s were much easier/better and they used HP tuners, had 3 vettes in there to tune. I may use them for parts services, etc. Guess I better not worry about them to tune the LT1 though. Funny thing, I saw the owners name as the tuner of an LT1 car in a magazine lol.

 

The only part of the tune on my 1992 LT1 that doesnt hold is the AC RPM adder. For some reason it always seems to revert to 25rpm. Other than that, the shop is talking BS.

 

2nd that. Might want to have them check your blinker fluid too. I'm sure they'll only charge about $200 for it. Good deal.

 

It's true! GM put together the LT1 PCM and it just worked, no tuning needed.

Oh wait, the shop probably reset the PCM and found the car ran great at first then it started running like crap cause the 02's doing the thing with big cams... hahah.

They really are dumb.

Mind sharing the name/address of that shop? It's just advertising right?

 

I think it depends on how the tuning was done, ie what tables were changed and which ones were not??? Meaning, over the long haul the fueling can changed based on the ST/LTFTs. But if they spent time with the car and kept tuning this would not be an issue.

ALSO, the aftermarket computers have better resolution and software which makes tuning them a little better than the LT1 stuff.

 

Its MD performance