Dyno Test Results for a 2003 Tahoe Z71

[Durkin]

One week ago, I had a baseline dyno test run on my stock 5.3L Tahoe Z71.

 

Results: rear wheel power at 90 MPH: Torque = 277 ft lbs; HP =

207.1; RPM = 5053 [ ]

 

Yesterday, we installed JBA Stainless headers, MSD Plug Wires, and a Flowmaster 70 Muffler cat back system.

 

Today, the dyno results are: rear wheel power at 90 MPH: Torque = 300 ft lbs; HP = 230.5; RPM = 5059.

 

So, about $1,400 gets you about 23 hp at the rear wheels (including the loss of an additional 12% for the transfer case that a 2-wheel drive would not have); that is about $61 per usable horsepower!

 

If you add up the claims for this equipment, they range from 32 to 38 HP at the flywheel; so if you multiply 23 RWHP * (1.25 + .12) [standard drive train loss + transfer case loss],you get 32 HP at the flywheel and that is at the low end of the claims.

 

On Friday, UPS needed a signature for the package and noone was home, so my Granatelli MAF and Predator tuner will not be here until Monday.

 

So next Saturday it is back to the dyno to see what those two items are worth.

 

Regards,

 

Durkin

[Wingnut]

Cool!

 

Welcome to the forum by the way.

 

Keep up posted.

[Durkin]

This is interesting!

 

Just relooked at the 90 MPH Dyno graph again; I counted the shift points and the truck was in overdrive at 3,950 RPM! Wonder what the reading would have in in 3RD (Direct) at 5,000 to 5,100 RPM?

 

We wil have to do this again!

 

Durkin

[Durkin]

link to the dyno graph:

http://mct.truckmoxie.com/showownerpic.asp...1&n=99307&pos=1

Durkin

[Gilbert]

From what I can make out on your Dyno Chart, your HP and TRQ do not appear to be shown a as a function of RPM? Is that correct? If yes, WHY?. Just a different chart layout I suppose. What type of Dyno did you perform your runs on? What units are on the horizontal? I can't make them out, should be RPM, but don't appear to be.

[Durkin]

Column headings (left to right are: MPH, HP FTLBS RPM. Did not a sk the dyno brand. Will try to get a better scan of this.

[rico750sxi]

Can't wait to see the results of the tuner and MAFS. Keep us posted please.

[Durkin]

OK!

 

Got the Granatelli (branded) Diablo Predator and the Granatelli MAF with cold air sensor. Installed the MAF; tuned the car with the Predator. Big kick in the seat! HUGE kick in the seat in tow/haul. Off to the dyno. We installed a set of platinum AC Delco 41-932 plugs (one heat range colder than stock) and stuck it on the dyno for eight runs. See my signature for the complete list of what the truck has on it.

 

One of the eight runs was unbelievable at 5,100 RPM:

Rear wheel horse power = 289 v. stock 207

Rear wheel torque =294 v. stock 278

 

The other seven runs were terrible at about equal to stock; Rats! HMM?

 

 

Started the truck up and noticed a check engine light; drove it home in reduced power mode. Checked the codes with the Predator and found DTC codes PO171 and 174 set (bank 1 and 2 lean); cleared the codes; added 2.5% WOT fuel pressure. Kick in the pants is back - big time; so back to the dyno in the morning!

 

More to come.

 

Regards,

 

Durkin

[99Silver6.0]

That Granatelli will lean you out a bit. If you run ATAP on your truck and check the LTrms I bet they are high. Which signifies a lean condition. Time for Edit!! When I descreened and ported my MAF I had to adjust the MAF and PE tables with Edit to get my LTrms back down.

[Durkin]

99Silver5.3:

 

Thanks for the info! Found this link on your website! http://carprogrammer.com/Z28/PCM/LS1/Holden_LS1.pdf

 

I have done a lot of research before I started this and barely looked at LS1 Edit because it looked too technical. Wish I had paid more attention to it. In any event, I am on the way back to the dyno this AM.

 

Thanks again!

[99Silver6.0]

I think that you can richen things up with your Pred! I dont know much about that programmer but I think you can.

[Durkin]

Did not go to the dyno yet, because after driving it around for 75 mies I am still throwing a lean code.

 

Feels like an LS1 Edit tune may be next!

[99Silver6.0]

Have you tried to richen things up some with your Pred.

[Durkin]

Removed the GMS MAF and addded 3% more fuel at WOT and am awaiting a custom tune from runninwiththedevil.

 

Regards,

 

Durkin

[Hotrod 496]

Diablo Sport will custom tune over the internet all you have to do is buy some cables at radio shack. I am in the process of custom tuning at this time , they seem to be real helpful. I am Having Problems with it pinging when i get on it in the cold wheater. Hope this helps you