STS towing question

**5kcstq** · 09-06-2006, 07:14 AM

Hello, I am a new member with some questions about my 2005 2500 HD Crew Cab with a 6.0 L GMC. My truck is stock except for a STS kit, including intercooler and Diablo sport tuner. At this point I am running 5psi with no problems towing a 9000lb load. I am very happy with the performance I am getting but was wondering if more is possible, mostly to maximize my investment. Some of my specific questions are:

1. Rick at STS has told me not to exceed 5 psi while towing this large of load. While this seems resonable I was wondering why can't you run more boost if you can keep fuel rations, intake and exaust temps under control.

2. What is the mechanical limitations( Eg. bottom end, top end) of the 6.0 L engine.

3. Is lowering compression( 9.4 -> 8.4) a good option or will I loose too much bottem end power.

Thanks
Mark Rutherford

**Nitrous** · 09-10-2006, 03:13 PM

I'd leave it just as it is. Who did the tuning on your truck? You might want to consider HPTuners for maximum performance if you don't already have it.

**farmtruc** · 09-15-2006, 08:55 AM

Originally Posted by 5kcstq

1. Rick at STS has told me not to exceed 5 psi while towing this large of load. While this seems resonable I was wondering why can't you run more boost if you can keep fuel rations, intake and exaust temps under control.

2. What is the mechanical limitations( Eg. bottom end, top end) of the 6.0 L engine.

3. Is lowering compression( 9.4 -> 8.4) a good option or will I loose too much bottem end power.

Thanks
Mark Rutherford

1. You can run more boost, but the average person (non gear head) throws one of these kits on and doesn't consider a/f ratio and egt's while towing. As long as those are kept in check, you'll be fine with about 8psi during towing.
just be safe with it.
2. I've seen a stock 6.0L handle 680hp with a turbo on an engine dyno. I beleive that was on 14psi. I have a customer that has seen as much 16psi on his stock 6L (ls6 cam also) and it's still running strong, however, he has a great fuel system (78lb'ers and fuel cell). My truck put out over 600rwhp on a stock 6L (bad blow by though)
3. Your engine has low enough compression, if you're wanting to change pistons, install some forged pistons.

good luck,
allen

**ss~zoso~ss** · 09-15-2006, 01:17 PM

sounds like some pretty sick trucks

**5kcstq** · 09-15-2006, 05:57 PM

Thanks, that was what I was looking for. If I am going to run 7 psi are the stock injectors going to handle it or do I need to go to a larger injector.

Again thanks for the info.

Mark

**koolaid_kid** · 09-15-2006, 08:08 PM

If you have not already, I suggest getting some gauges to monitor your readings, especially your EGT and boost.

**5kcstq** · 09-16-2006, 06:03 PM

I do have a boost gauge and a narrow band A/F set to full range of 1 - .5 mv. In the near future I plan on on wide band A/F, EGT, and Knock indication. Any other suggestions out there.

**farmtruc** · 09-16-2006, 07:39 PM

Stock 24lb injectors will not cut it! Not even with 5psi. You'll need some 42lb Multec injectors. They are a direct swap. Or go with the 42lb LS1 injectors, but injectors connectors will be needed.
My stock Avalanche can take 5psi with no injector upgrade because it's flex fuel and has 38lb stock. If yours isn't flex fuel, it only has 24lb'ers.

The most important gauge IMO, the wideband, very useful and IMO mandatory.

good luck,
allen

**Nitrous** · 09-17-2006, 07:12 AM

You heard it form one of the best 5kcstq! Allen will lead you in the right direction.

**patrik choma** · 09-21-2006, 10:57 AM

Hi i am new member i have 2000 6.0 silverado .i put inside hight flow mufler,volant coold int. hypertech programer and truck is not powerfull.i do not know if it is only my truck ?

**patrik choma** · 09-21-2006, 01:16 PM

Originally Posted by patrik choma

Hi i am new member i have 2000 6.0 silverado .i put inside hight flow mufler,volant coold int. hypertech programer and truck is not powerfull.i do not know if it is only my truck ?