If you have a radically modified LT1 that needs to spin 7000+ rpms, it will be limited to the stock pcm capability, which I think 7000-7200 rpms. Now, if you have a motor thats stays under these rpms, why waste money on the LS conversion? The optispark will be your weakest ignition link.

The LS1 pcm on the other hand can be tuned to 8000+ rpms, as long as you have the motor combination that can make power and handle the higher end.

Stock for stock LT1/LS1 pcms, no horsepower difference.IMO.

 

O I agree that stock for stock you wouldn't really see much if any, assuming both systems are working properly. I'm just saying there could be more HP to be made on the top end! And ask the question how much more HP can you get outta the extra rpms? And I'm not talking about on a stock setup.

 

Reasons I like the conversion is of course no more opti crap, I absolutely love HP Tuners, they have a great user friendly forum, and I am actually tuning my own car now and its not to bad (mods in sig).

As far as more power from a LT1/LS1 computer, who knows, but the 411 LS1ECU is awesome. I just upgraded to a 2 BAR SD Custom OS with RTT. ITs awesome

Not too many people tuning LT1's anymore, and there will be even less in the future IMO.

 

We've been seeing consistent horspower and torque increases throughout the RPMs when comparing LT1 PCM to LS1 PCM on LT1 engines. These numbers are not staggering, but the conclusions we are coming up with (and feedback from other tuners) is that the increases are due to ignition timing accuracy (the LS1 PCM fires injectors and coils based on crank position). Having dyno'd several 24x LT1 engines (350ci thru 396ci) TPIS is suggesting that the gains are more noticeable with engines that have higher cylinder pressures.

The November 2011 issue of Car Craft will have a writeup on this. The engine in this article is a 383 LT1 and demonstrates an LT1 PCM and LS1 PCM comparison.

 

congrats on the recognition of your hard work in the magazine Mike and for doing this for the LT1 crowd to create an option.

 

Thank you for the kind remarks. Mark really gets the credit for the LT1 conversion. I originally had little intentions on moving forward with LT1 support.

 

I'd back that up also. I haven't done a before and after but a ton of LT1s we have come threw the shop will have ignition problems over 6500 RPM. You might not hear it on the street but it shows up on the dyno. The ls1 controllers are much easier to get a better result with.

 

I second that. Thanks for the great option for LT1 ignition and tunability. I couldn't be happier.

 

Tis the only reason i did the swap. Rid of the opti and be able to tune it myself/ better . My car is only going to be heads/cam, full bolts on at the most only spinning to 6 grand roughly.

The option is there later if i want it so, woo for eficonnection

 

x2. Great product and awesome results.

 

Getting ready to start my conversion. Lost interest in the car for a few years. Looking forward to a better running setup. Better springs and pushrods will be done at the same time. Hoping to knock off a few more tenths. Times in my sig were ran with 6300 RPM shift points. Looking forward to shifting closer to 6800 without the breakup I seem to get whenever the opti gets a little tired. Haters stay away. I,ve been thru 4 optis in 7 years. Not gonna spend the cash on another one. Wish me luck.

Mec

 

Lets talk grounding! how is everyone grounding there DIY harnesses? right now I think I have something dropping out. It wont fire everytime and when it does it will run rough and then loose all throttle response within a few seconds like if you left VATS on. I have all the grounds shown in the wiring diagrams broken out individually and then combined into one point at a ground distribution block and then 0 gauge wire that runs straight to the battery in the rear...

 

Ignition issues are commonly related to an incorrect crank reluctor install. Intermittent ignition issues are typically a loose crank reluctor (crank bolt is too long, not tight, or the crank hub is not flat).

I would recommend wiring the sensor grounds just like and LS1 harness. I'm not convinced this is required, but have never done it any other way.

 

Just got mine up and running on a DIY harness, aside from a really shakey tune things seem to be working great. Getting all the details sorted out now... gets better every time we drive it and all i can say is awesome product guys!

 

I guess that whoever believes in your mail order tunes also believe in unicorns and tooth fairies.

I guess you would say the same thing against an E38 right?

And of course... I wouldn't think that you feel that the scantools available for the LT1 are up to the task as the ls1 scantools available right? That alone is worth upgrading the ECU. Heck that alone is worth getting an E38 over the LS1. But to each its own.

 

Cant wait to start my project with the DIY harness. Still tracking down the last of my parts needed.

 

Same here... Ive got the 97 cover, a bid on a harness, and was the top bidder on a set of truck coils with harness and brackets for $25 but some fugger outbid me by $1 at the last minute...

 

whats the part number for a double roller 24x reluctor?

 

Not sure if this has been answered before but here it goes.
My question is, can you doubt the tuner even though he says he can do it and has had experience tuning the LS1 pcm's but never done the Efi conversion on an LT1 before? My tuner guy is supposedly good around the area we shall see but he's never done the conversion before, should I be worried? Long story short, I took the car for dyno tuning he didn't finish because I wasn't happy with my setup so I changed it. It seems to run pretty good considering that he is not done tuning it. But my gauge rpm's are not correct with the actual engine speed and when I took it down the road and back I got a check engine light indicating a no #2 knock sensor which I'm running the single knock sensor that I bought new from Gm 1997 knock sensor. Everything else seems to be done away with as far as evap, egr, rear o2s, etc. Right now I'm giving him the benefit of the doubt. I am scheduled in for Final tuning 5/26/12 so until he tells me he is done with it I can't say nothing bad about the conversion or my tuner.