no_radio

Just got my HPP from a Forum member (great deal, thanks!). I mainly bought it to turn the fans on earlier, and for when (if?) I install deeper gears or a lower temp stat.
But, I have heard that the Power Tuning Program has made some cars run slower at the track. Anyone have experience with this, particularly with an LT4? Does it have any other side effects (positive or negative?).
Should I head to the track and run my car stock, then with HPP and see the effects for myself? I'd rather not abuse the '96 too much...85K miles on the stock clutch and it's a daily driver...not up for a clutch job any time soon.
Thanks,
Jeff

Vette Ed

I just installed the hypertech program yesterday and it fried my pcm unit.
I sent them the pcm and unit back. My can is dead-in-the-water right
now :smash:

vader86

performance settings on that thing are worthless

ninetyfivevette

If the information I have read on the 'net can be trusted, the HPP III is the version that can actually cause a power loss, while the HPP III+ (note the "plus") supposedly fixed the problem.

This is just what I have read, so you may want to call them to verify.

I concur that it is pretty worthless as I have one too, for the same reasons as you, turning fan on earlier, correcting for new gears.

RadPolo96

I didnt use the power programming specifically for that reason. I just went through and changed all the things I thought needed to be changed and that worked just fine :thumbs:

no_radio

That's how I have it setup right now.
I think the box said "plus" but will have to look when I get home.
Thanks!
Jeff

rcolling

I tried the Power tuning on mine and while I have no proof I feel I lost power. I then reset it to stock and just use it for fans.

After thinking about it I keep wanting to try the Power Tuning again and this time use a mix of Premium gas, 91 Octane here, and 100 octane gas. I know the LT4 has a high compression ratio, 10.8:1 and was designed to run with premium that was 94 octane at the time. I am just wondering if that will make a difference...

Lone Ranger

One thing I learned about the HPP after talking on the phone to one of their techs: When you select to program the car back to stock (totally ditch all hypertech features and reinstall stock program) the final act the unit does before the programming process is done is to clear any stored codes and clear the learned performance memory, i.e. it basically does the same thing as pulling the battery power. So when driving the car after reinstalling the stock program the ECM will be in relearn mode for the first however long 20 to 50 miles or so same as if you had disconnected and reconnected the battery.

That might account for why the car feels stronger just after reinstalling the stock program.

But I still just use mine for fans and shift firmness. Mine is a Power Programmer Plus-- doesn't say anything anywhere on it about III.

LT4CEZ51

Although I've never personally used the HPP III, I have a friend who has (Duntov). He has the dyno results to prove that the performance changes are worthless. If I recall correctly, he picked up about 1 hp, and lost about the same amount of torque. This is probably within the tolerance window of the dyno itself, meaning the programming really didn't do anything of significance, if at all. If Matt sees this, hopefully he'll give you the exact numbers.
Hope this helps.
Ted
96 CE LT4 Z51

95AquaC4

I am racking my brain trying to find a better way to say this....guess what...vader said it just right. HOWEVER, for us automatic guys...the shift firmness and shift point tuning is absulutely awesome! My car shifts bada**! :yesnod: I also used it for my gear swap, and for the fans.

LT4BUD

Per the HPP instructions, the fans will turn on at 192 and off at 185. I posed a question related to this on a recent post and got no responses. It would be my opinion that these temps are a little too high to get the full benefits from a 160 stat. I had a very early version (96)on my LT4 which apparently put the fans on much earlier and the car never went above about 178 even in traffic.

Regarding performance all I can say is no seat of the pants difference.

HPP replace my original programmer at no charge since in would not reprogram for the 4.10 gears. This was in Nov 2001.

redcorvettedave

quote:
________________________________________ ____________
. HOWEVER, for us automatic guys...the shift firmness and shift point tuning is absulutely awesome! My car shifts bada**! I also used it for my gear swap, and for the fans.
________________________________________ ______________________

I have reprogramed the gears, and fans with my HPP+... but I would like to know what setting did you tune on your A4 to get that awesome shift points???


________________________________________ _______________


[Modified by redcorvettedave, 3:07 AM 4/19/2003]

Joeyvette

I would love to know the shift points myself if anyone knows. Thanks guys.

95AquaC4

Well, the shift firmness is easy. It's either set to firm, or not. For shift "points", you can add mph to each upshift depending on where your shifting at the track. For example, my A4 was shifting into fourth a few hundred feet before the line. By adding mph(2 I think) to the 3-4 upshift, I was able to delay the shift until the line.

silver & red CE

The 4L60e/700R4 has a big step from 1st to 2nd gear. I'd bump the 1-2 shift point up 3-4mph, but you'll have to extend the rev limiter too. On my Impala SS, bumping the 1-2 shift point up 3 mph is worth about a tenth second in the 1/4 mile. By moving the shift point up you give away a little waiting for the shift as the HP is dropping off (from the higher revs). But you start out in second gear at a higher rev point (futher up in the torque band) and as a result, have a faster time.

Eric

Lone Ranger

Important to realize there are two fan speeds involved, low and high. On the HPP+ for my '95 using the 160 tstat fan settings the fans turn on low speed at 185-- you can't hear them with motor running but can see them spinning and if you shut the motor down you can then hear them spin down. They go to high speed at 192--you can then hear them 'roar' when the engine is running same as if the a/c was turned on. So what the HPP+ is doing is first turning them on low rpm at 185, but if low rpm fan speed doesn't keep the coolant temp in check then at 192 it kicks them into high rpm. There should also be a vehicle speed at which the fans are turned off referred to in the ECM as hysteresis speed, for instance it might be, say, 30mph and the fans get turned off because running them beyond that vehicle speed would actually begin to obstruct the ram air flow to the radiator. If anyone knows the hysteresis speed for the fans in the LT1/4 ECM please advise-- I don't.

The downside of the above is that in summer the fans run quite a bit, i.e. wear and tear on the fan motors.


[Modified by Lone Ranger, 9:10 AM 4/19/2003]

Phil-tha-Rush

yes..this is the only way to know for sure.

also, a couple guys asked about shift points (raising the shift rpms).
going to the track and gradualy increasing the shift points, and checking times is the only way to properly set them.

I have mine set at +3 for the 1-2 shift.........+2 for the 2-3 shift.

C4kid94

I dont even get out of 2nd on the 1/4 untill right after the line, whats the deal, do you guys have taller gears? But would you say the HyperTech is worth it?

richy rich

As far as going to the track & testing-I ran my 94 coupe w hypertech & it ran a best of 13.13@ 106.mph.Without the hyper-3 it ran 13.06 @ 106.50 mph.with the stock tuning!MY car is very stock [k-n,air-foil,zz-4 cam].I now just use it for the fans & shift fimness until PCM FOR LESS sends me a new pcm when my paypal is activated.