383tpimachine

I beg to differ. I expect to have a viable car with my 411 pcm whereas if I had stuck with the POS that comes in 85 I would not be able to use my motor setup AT ALL.

Would I have done it if I had a 325-400hp 355? Hell no. But others will and can build on it in the future.

confab

I expect better throttle response and tunability would be worth quite a lot, actually.

But, to each his own.

odxr

The gm ecm is a proven unit-but I dont like the fact that you have to buy a license per vin#to use the hp tuner or efi live.An ecm is just a microprocessor and some memory chips.I wired an australian Vipec efi unit into a turboed Datsun 280z and used it to fire chevy ls coils.Even with a custom camshaft the engine idled very smooth.No timing light bounce from the crankshaft gears that have a little slop in them.Very smooth idle even with a custom ground cam.In the end you will only like the efi system that has software that you find is easy to use.FYI-at most of the tuner shops usually the dyno operator only knows 2 or 3 different kinds of tuning software.If you are not going to do your own tuning/data logging and only have 1 or 2 local shops find out what they use-understand.

Orr89rocz

The gm tpi computers 165 and 730 are extremely capable units. I have had both of those plus did the 411 lsx conversion on my car. It doesnt really change the way the car drives. Once all 3 are tuned, its not a whole lot different. Hptuners lsx stuff has alot of tables and features, but i dont think they are that much more helpful in getting cars to drive right.
The 85 stuff isnt great, i would upgrade to the 86-89 type maf or go speed density. Ideally cheapest bet with great tunability would be EBL flash from dynamic efi

Its cool to see a sbc with coil packs tho. Throws ppl off all the time

DVNCI

I put the EFI Connection kit on my 96' - but my stock dash/controls are long gone.

I wanted it for tunability with boost.

You can make a pre-LS computer work with boost but they don't "understand" boost so to speak.

I didn't go with an actual LS motor because a) I hate the way they sound and b) don't like the way they look.

Plus, I just like doing something different, so I brought my "old" LT1 motor into the new millenium with more sophisticated electronics.

confab

aDigitalPhantom

Tunability yes.
Throttle response no.

Orr89rocz

90-92 fbody ybody type speed density 730 ecm is fine with boost. Just need to run code $59 through it. Its not the greatest code for driveability and etc but is very capable. Its got a true 3 bar ve and spark table
I have been 9.73 on that setup.

Other option is dynamic efi EBL flash for the 730 ecm. It has a boost multiplier to the injector pulsewidth that also works very well and keeps all the same stock oem L98 controls emissions and driveability

DVNCI

Yep, didn't say it couldn't be done, but you mention an important aspect - driveability. No way you'll get the older ECM's to drive as well as the newer boost capable PCM's.

Also - even though you have "extended" your ECM, I would argue the ECM still doesn't understand exactly what you are trying to do - but the hackers (luckily for all of us) have figured it out.

For drag racing, where you are at WOT 100% of the time, I doubt you'll see any difference whatsoever. I'm building a street/strip car though, so I want max drivability .

TorchTarga94

What do you have for gauges? Any pics?

Orr89rocz

May depend on the setup. I had both on my setup that currently runs 8.40's and could not tell you a difference in drivability.

And what do you mean by doesnt understand what its looking at? Both systems have a cam sensor timing type element, (one a sensor one a distributor), they both have a map sensor that reads 2-3 bar. they both take that signal and calculate fueling and inject the amount.

80-90's ecms are not as stupid as you make them sound. Code $58 is factory code from gmc typhoon syclone turbo trucks. $59 is a cleaned up version. They understand boost very well. Even have boost control, and measures to change fuel and spark via intake air temps

Lsx stuff does same thing except doesnt have boost wastegate control lol

DVNCI

Custom dash that was built by the guy that did my solid rear - I'll get some pics up in next couple weeks. I've been meaning to put some "finished" pics of my car up for a while now, need to get off my *** and do it.

I meant that historically people had to play a lot of games to get a boosted car to run right because there weren't MAP tables for above 1 bar. Same thing for people that "pegged" their MAFs.

I had completely forgotten about the gmc typhoon stuff! I assumed the $59 was some kind of hack that somebody did - I see now it's much more "factory" than that so I can see what you are saying now.

Out of curiosity - what is the "resolution" for above 1 bar? With HP Tuners it's every 5 kPA.

I'm definitely not saying the older ecm's are "stupid", just that the tunability (i.e. drivability) is a lot better with LS PCM's - also there are a LOT of folks with HP Tuners experience these days - it's much harder to find someone to tune the older cars.

Tom400CFI

I completely agree. Chevyowner has posted several times in this thread that there will be no meaningful gains or improvements. The ROI on this project is absolutely terrible.

As for throttle response, any of the later model engines "LS" or Gen III^ have much worse throttle response than the L98 or LT1.

confab

You can't tune the thing now. It takes piggybacks or UV erasers.

It's a horrible PITA.

confab

And if I'm going to make it truly tunable.. Shouldn't it be as tunable as possible?

Why do half measures?

aDigitalPhantom

I could be wrong, but I understand the reason that many people complain about the LS engines throttle response is because of drive-by-wire. Also that if you use a cable throttle it's not an issue. For my swap I used a cable throttle, and IMO it is the same or better then the LT1 I removed.

esham

Were you able to keep cruise control with the cable throttle?

Tom400CFI

It could very well be. I've certainly noticed a correlation between E-throttled engines and slow, sluggish response. In search of a solution (which I never found) for my C6, I took these videos...
First my wife working the pedal:



Then, what that looked like at the TB:



I couldn't believe it! It moves as fast, and as quick as a throttle motivated by a cable. Still, the response of the engine is S L O W.

crowz

I know on bmw's the pre electric throttle body cars are much more responsive than the electric ones. If the throttle plates themselves are responding as fast then for some reason the ecm isn't adding fuel as fast or timing on the electric pedal models for some reason. Might be a safety feature?

crowz

Found this :

http://www.jegs.com/p/Sprint-Booster...34709/10002/-1

If this gadget is legit then it would seem its by design. Doing more reading now to see if that's the deal.