Searching for a needle in a haystack! 2001/2002 Express Van 8.1 4L80Ee factory tune

[Fast355]

As the title says I am searching for the factory tune for the 8.1 I am about to swap into my Express. I would love to have the Hypertech version too, but will take what I can find.

[1project2many]

Maybe we can dig up a valid vin??

I see a coupe of the older Hypertech programmers on Ebay for about $100 that list for 8.1.

http://www.ebay.com/itm/Hypertech-Power-Programmer-30012-/321932966489?hash=item4af4b33a59:g:a9gAAOSwcBhWWPE D&vxp=mtr

http://www.ebay.com/itm/NEW-HYPERTECH-30007-ECU-POWER-PROGRAMMER-III-8-1L-CHEV-GMC-01-2500HD-/391329230166?hash=item5b1d0a2d56:g:WSsAAOSwgQ9V6Mi 3&vxp=mtr

[mecanicman]

Have you ever looked at a hypertech tune? They are a joke. Not worth your time.

[Skinny Pedal]

Whats the reasoning for the 8.1 express? Its going to be an even more de-rated tune than a truck. None of them were drive by cable. Just curious as to why the van.

Also agree the hypertech stuff is a joke. I keep a few TBI proms around of theirs for when I need a good laugh.

[Fast355]

I spent alot of time on the dyno when I had my 206/210 cam in my L31 only to find out that the Hypertech spark table was within 1-2° of perfect for the L31 in my Express. I also ran the Hypertech in my Titan and that truck put down 300 RWHP on a Mustang dyno and 390 RWTQ with only the Tune, Airaid CAI, and Magnaflow muffler swap.

Its also going in an Express so makes sense to me to have the operating system match the vehicle.

The tune I used in the 99 L31 Suburban was also Hypertech based.

When I traded off the Titan, I put the Hypertech on my Mom's Nissan Pathfinder with the 4.0L. It SCOOTS along very well.

[Skinny Pedal]

Its also going in an Express so makes sense to me to have the operating system match the vehicle.

Doesn't matter with half meg ecm. There is no real difference between trucks and vans, especially by the time you throw a canned tune on there.

Now you get into 1 meg and that's a very different story until the vans went DBW.

[Fast355]

Doesn't matter with half meg ecm. There is no real difference between trucks and vans, especially by the time you throw a canned tune on there.

Now you get into 1 meg and that's a very different story until the vans went DBW.

There is a HUGE difference between the trucks and vans. The trucks run the Allison 1000 with a seperate TCM and the vans run a 4L80E.

[Skinny Pedal]

Not all trucks. There is also the suburban tunes. Or you can make a van file if you really want one with a few simple segment swaps.

Here nor there though. Was just wondering why the needle was so important when you could use the hay.

[Fast355]

Not all trucks. There is also the suburban tunes. Or you can make a van file if you really want one with a few simple segment swaps.

Oh I forget about them. Avalanche was made with an 8.1 too IIRC.

[Skinny Pedal]

Yup. DO you have a vin for an express 8.1 by chance? If you do I'll get you a stock tune.

[1project2many]

This should be a valid VIN for an '02 Express Cutaway with 8.1: 1GBJG31G721191799

Someone with access to TIS might be able to get a calibration for you.

http://chevroletforum.com/forum/vindecoder.php?vin=1GBJG31G721191799

After looking at the above info, I'm not sure you'll like the 0 mpg highway / city ratings. ;)

[Skinny Pedal]

Awesome. Give me a few and I'll get it.

[Fast355]

Yup. DO you have a vin for an express 8.1 by chance? If you do I'll get you a stock tune.

I have someone getting one for me. It was a factory 8.1/4L80E/4.10 gear/10,000 lbs tow package tune which is what I will be using.

[Skinny Pedal]

What format do you want it in?

[Fast355]

What format do you want it in?

I am using HPT. Can use it in .BIN or .HPT.

Vin I have is 1GAHG39G811159594

[Skinny Pedal]

I am using HPT. Can use it in .BIN or .HPT.

Vin I have is 1GAHG39G811159594


K. I'll run both Vins and get the files up.

[Fast355]

K. I'll run both Vins and get the files up.

Thanks! I was actually thinking of asking if you would run both. It will be interesting to see what differences there are.

I have a 2003 5.7 calibration from a P30 that is almost identical in every way to a 2002 5.7 G1500 as far as the engine tuning is concerned. I was amazed to find the EXACT same timing maps in both tunes.

[1project2many]

Yes, it will be interesting. The VIN I posted is listed with the 340 horse version.

P vans were usually way behind the 8 ball in development. They continued to get 6.5 NA engines long after the rest of the GM line went to turbo plus PCM.

[Fast355]

Yes, it will be interesting. The VIN I posted is listed with the 340 horse version.

P vans were usually way behind the 8 ball in development. They continued to get 6.5 NA engines long after the rest of the GM line went to turbo plus PCM.

Weird that the GM information package I ran across says ALL G-vans have the 340 HP version. Now the Vin decoder I believe is in error because it shows the L29 power ratings with the L18 engine RPO. The 8.1 has ZERO problem smoking the tires and letting a long wheelbase Express van drift.

[1project2many]

Yes, that decoder probably is wrong. But I wouldn't be surprised if it uses actual GM information.

I'm going to guess that you can't overcool that transmission.

[Skinny Pedal]

May be the morning/late tonight before I get the tunes up. Gotta finish out some paying work tonight to ship tomorrow.

This work stuff... Pfff

[Fast355]

I'm going to guess that you can't overcool that transmission.

Actually believe it or not with the current 350 the factory sending unit says it runs about 130-140°F running down the highway in just about any temp. I have the factory in-radiator cooler plumbed in front of a massive Derale cooler with a pusher fan. At idle I have seen it creep up to the 170-180° range on a 105° day but once moving in lockup the temps drops like a rock. I was really surprised to see it that cool when I logged the temps with HPT.

[Fast355]

May be the morning/late tonight before I get the tunes up. Gotta finish out some paying work tonight to ship tomorrow.

This work stuff... Pfff

I know how that goes! Was stuck there from 9-7 myself...Pfff

[mecanicman]

I can set you up with an avalanche 8.1/4l80 file that would work with your pcm like the other one I made for you. Need a copy of the licensed file in the pcm. Also I have a hypertech tune from a 2002 5.3 truck if you want to see how bad they are. If i remember correctly they added 2 degrees of timing to the bottom 1/2 of the timing table and made a couple of trans firming mods. Thats it.

[Fast355]

I can set you up with an avalanche 8.1/4l80 file that would work with your pcm like the other one I made for you. Need a copy of the licensed file in the pcm. Also I have a hypertech tune from a 2002 5.3 truck if you want to see how bad they are. If i remember correctly they added 2 degrees of timing to the bottom 1/2 of the timing table and made a couple of trans firming mods. Thats it.

I may need that done. Would prefer the Express timing maps but it could very well be the same thing.

I have a Hypertech tune for a 1998 C1500 it was not bad for what it was designed for. They tuned it for WOT power at or near sea level. They left the part-throttle stuff stock for emissions reason and altered the WOT timing/fueling. I blended the WOT spark map with very minimal changes into the stock timing map to make the one I used in my Express and the Suburban.

Blackbox
http://i243.photobucket.com/albums/ff172/Fast355_album/attachment-2_zpskhqldydp.jpeg (http://s243.photobucket.com/user/Fast355_album/media/attachment-2_zpskhqldydp.jpeg.html)

I adapted the same table more or less to the 0411.
http://i243.photobucket.com/albums/ff172/Fast355_album/attachment-2_zps75x1guko.jpeg (http://s243.photobucket.com/user/Fast355_album/media/attachment-2_zps75x1guko.jpeg.html)

[Skinny Pedal]

Sorry got called out of town to tune some ponies before the snow hit. Dang mustangs.

As promised.

[Fast355]

Sorry got called out of town to tune some ponies before the snow hit. Dang mustangs.

As promised.

No problem, atleast tuning the ponies pays the bills!

I downloaded both and found some interesting stuff.

The cut-away van has the same exact timing map I pulled out of a Workhorse RV and is the same as a Kodiak/Topkick truck with an Allison behind it. The single rear wheel van has the same exact timing map as a Suburban/Avalanche. However the MAF table is unique to the vans as is the throttle mapping. The dual rear wheel van has less torque management restriction than the single rear wheel van. Both of the van setups have more line pressure programmed into the 4L80E than the Suburban/Avalanche. The van however does have more shift torque reduction on the 1-2 and 2-3 shifts than the Suburban/Avalanche.