RE: 6.5 Power Upgrade

[bsharp]

I have a 1997 K2500 with low mileage (86,000 Km or 53500 miles) - 3.73 rear end. I was thinking up upgrading its power so it will pull my fifth wheel trailer better in the mountains.

I spoke to several people and they said that the transmission may not be able to take more power. It is a 4L80-E Automatic (I believe that is what it is). The advertised horsepower is 195 and I believe the maximum torque is 430.

I note in the owners manual that the same transmission was put in truck with the old 454 gas engine which produced more power than the 6.5. so I think it can take more power and torque.

I was thinking of putting a performance exhaust system on it plus changing the computer which is supposed to give 30-40 more hosepower and 60-90 more ft/lbs of torque. I could do this for a reasonable price but don't know if it would cause more problems with the transmission, rear end, etc. etc.

[AndyL]

The 97 is factory rated at 190 HP and 395ft/pd, the 4L80E is rated at 450 or 475ft/pounds and is a very good tranny capable of handling many performance upgrades.

The best and easiest method for more power:

1. Gauges first, this is a must.
2. www.KennedyDiesel.com (http://www.KennedyDiesel.com) 3.5" exhaust.
3. Heath Diesel ECM reflash. 60 HP and 150ft/pds.

I have both of the above and many others on the board will confirm that it is a great combo.

Andy

[JoeyD]

Go with a intercooler. This is the most important item GM didn't include. This will keep the power you have when your loaded up and towing.
Then get yourself an exhaust system from turbo back.

[rjschoolcraft]

My Suburban is making substantially more power than stock. My transmission is handling it well. See my 6.5 Performance (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=006650) thread for more info.

[Turbine Doc]

I have basically same set up as Ronnie Joe, with exception of PCM reflash, (I run a Heath PCM reqd for OBDII and RJ runs a JK chip) not problems to date with extra Hp.

Since I occasionally tow heavy 13K trailer/load I asked my tranny guy if there were any concerns with 4L80 high Hp and weight.

No concerns if keep the fluid-filter changes at regular interval and keep it cool, I added deep pan, extra cooler, and just for extra comfort zone had HD clutches put in (this was my idea not a reccomendation that they were really needed, but at up to $2K for a trans overhaul wanted things as "bulletproof" as possible for the long haul).

[DA BIG ONE]

4L80E is up to the task, and there are many upgrades for it to handle in excess of 1200 hp.

Gm's 572ci rat motor "street version" pounds out just under 700hp with pump gas on the dyno and the only tranny option I have seen for it is the 4L80E, or a manual shift only 4L80.