Engine/Transmission (1998.5 - 2002) how much stock boost?

[johncameron]

How much boost does the 01HO 6 speed engine produce? I'm getting 18 PSI at WOT. The Banks Big Head wastegate is supposed to give you 5 more PSI: has anyone tried one or have any other ideas to get more boost?



Long live Cummins!!!!

 

[RustyJC]

Mine made around 20-22 PSIG stock. The generally accepted method to get more boost is to use a boost fooler (to keep the ECM from defueling and setting overboost codes) and a boost elbow on the turbocharger. With the Edge EZ (which has a built-in boost fooler) and accompanying boost elbow, I made about 30 PSIG with stock injectors. With the DD2's, peak boost is around 33-34 PSIG.



The additional boost really helps in dropping the high EGT's the HO is prone to run in stock configuration. When towing our 13,500 lb 5th wheel, I could hit 1300 degF pre-turbo EGT stock. With the EZ, BHAF (big honking air filter) and 4" exhaust, this dropped to 1100 degF with stock injectors. The additional fueling of the DD2 injectors has brought it back to 1225 degF, still well below stock levels and making 340-350 rear wheel BHP and 750-800 lb-ft of torque.



Rusty



Rusty

 

[Sageair]

RustyJC. Did you add the EZ,BHAF and exhaust at the same time or do you know how much each affected E. G. T? Thanks.

 

[RustyJC]

I added the BHAF first. No effect on EGT that I could detect - 25 degF tops.



Unfortunately, I added the EZ (with boost elbow) and 4" exhaust the same weekend, so I don't know how much each contributed to the 200 degF EGT drop. If I were a bettin' man, though, I'd say the EZ and associated increased boost were worth 150 degF and the 4" exhaust probably 50 degF.



Rusty

 

[SLindblom]

Same here, what Rusty JC said. I got 22-23 lbs boost stock on my 01 HO. High EGTs (pre turbo - 1250 + until I started feathering the throttle) last summer pulling a gooseneck with 4 4-wheelers and some camping gear in Utah. I put on a 4 inch exhaust when I got back, but haven't pulled anything since. I added an Edge Comp and BHAF on New Years, and the boost fooler pegs my 30lb boost guage. Haven't had time to replace it yet. Haven't had any high EGT's since

18 lbs sounds a little low

 

[Tcolesanti]

A friend of mine has an 01 HO, he pushed 21-22psi bone stock with a straight exhaust. He installed Bullydog 60hp injectors and the max boost went up to a solid 22-22. 5psi.

 

[RustyJC]

Originally posted by Tcolesanti

A friend of mine has an 01 HO, he pushed 21-22psi bone stock with a straight exhaust. He installed Bullydog 60hp injectors and the max boost went up to a solid 22-22. 5psi.

That's because, if he doesn't modify the wastegate function (boost elbow) and trick the computer (boost fooler), the ECM will see the high boost pressure as reported to it by the MAP sensor and defuel to hold maximum boost to the 22. 5 PSIG figure you mention. The injectors want to add the fuel at max load, but the ECM won't let the VP-44 deliver it.



Remember, ya gotta have air first if you want to add fuel for additional BHP. If ya add the fuel without the air, all you'll make is smoke and heat (high EGT).



Rusty