Engine/Transmission (1998.5 - 2002) he351ve or pac

[PetesonM]

I have been kicking arround the idea of doing a he351ve turbo on my 99'. I get a better turbo (kinda) plus exhaust brake which is what i really want. there is more work involved but for the $ it seems be the best move. so how does the ve and say like pac compare in braking power? or do i bite the bullet and get a turbo upgrade then a brake sometime down the road? any thoughts here? experences?

 

[LNaugle]

The ve doesn't work anywhere near as good as the Pac Brake... Also it would probably still have the sooting problem.

 

[AH64ID]

The VE can produce a substantial amount of backpressure at low rpms and both the Pac and VE will peak at ~60 psi so peak retarding power is going to be equal. The only place they may differ is below 2000 rpms.

 

[LNaugle]

Seat of the pants with loaded trailer, pac brake hands down... The most i have ever seen on the boost gauge is 10 psi on my dads 08 but it is an auto.

 

[CKelley1]

as stated pac hands down. look at a bd, works as good as pac but has a better compressor location than the pac giving far superior life.

 

[AH64ID]

Seat of the pants with loaded trailer, pac brake hands down... The most i have ever seen on the boost gauge is 10 psi on my dads 08 but it is an auto.

You will never see boost on a Pac because it doesn't increase the speed of the turbo like a VE brake does. The VE boost goes up becuase the tight vanes spin the turbo faster and make boost (combined with the restriction of the airflow out of the motor). The pac stop the airflow after the turbo, and thus slows the turbo down.

The OEM tuning for the VE is not the same as aftermarket tuning with a Fleece controller for the brake. You can make it brake harder down low if you want to.

The Pac has the potential to block more air at very low rpms, but even down that low I am not sure that the retarding hp increase is huge. A VE should be able to build peak back-pressure before 2000 rpms giving equal power up thru redline.

 

[LNaugle]

You will never see boost on a Pac because it doesn't increase the speed of the turbo like a VE brake does. The VE boost goes up becuase the tight vanes spin the turbo faster and make boost (combined with the restriction of the airflow out of the motor). The pac stop the airflow after the turbo, and thus slows the turbo down.

The OEM tuning for the VE is not the same as aftermarket tuning with a Fleece controller for the brake. You can make it brake harder down low if you want to.

The Pac has the potential to block more air at very low rpms, but even down that low I am not sure that the retarding hp increase is huge. A VE should be able to build peak back-pressure before 2000 rpms giving equal power up thru redline.

Thanks for explaining that to everybody, as i am very aware of how both systems operate. I didn't state that the pac would make boost.

 

[AH64ID]

Thanks for explaining that to everybody, as i am very aware of how both systems operate. I didn't state that the pac would make boost.

Then why would you bring up boost in a question about braking? I apologize for explaining something you knew, but your comment didn't indicate that you were aware of the differences, and how/why boost was made during exhaust braking.

 

[Vaughn MacKenzie]

As for turbo performance I know a number of people have run them, but I never hear anyone comment "What great turbo. " I ran one for a few thousand miles on my '01 with a Fleece controller but I was not impressed. I put a regular HE351 on it later and was a lot happier. The VE always felt corked up and I never was able to dial it in to my liking.

 

[AH64ID]

The VE and the CW share the same compressor wheel, but the turbine wheel on the VE is larger. Then there is the obvious difference in turbine housings.

After watching a drive pressure gauge for a few years on a HE351 I was all too happy to ditch it. I was going to do the VE swap but decided against it at the end and went with the Garrett.

It would probably take a bit of tuning to get the Fleece dialed in, but once it's done the VE has better exhaust flow and lower drive pressure for the same boost.

 

[LNaugle]

Then why would you bring up boost in a question about braking? I apologize for explaining something you knew, but your comment didn't indicate that you were aware of the differences, and how/why boost was made during exhaust braking.

I was just commenting that all the boost gauge says is 10 psi when using the factory exhaust brake. I realize that that is not an actuall number to compare exactly to your 60 psi statement... . I apologize for making it confusing.

 

[PetesonM]

Ok,so the exhaust brake works well prob not as good as the pac but well. He351ve good turbo on these 24 valves? Vaughn you said that you ran it but were not impressed you said it felt "corked" I assume that you played with it and the controller a lot and tryed to make this combo work? anybody else with true world experence with this turbo? Im just looking for a little extra umf, and some better egt control without the big turbo lag. hx40 is always a option but that small shaft concerns me a little. long and short I understand you have to pay to play but a turbo and an exhaust brake is a big investment and thought that this may be my answer and a little money saver but maybe not????? Thanks to all for replys and info!!

 

[AH64ID]

The 7-blade HX40 (the desired one) and the HE351VE use the same compressor wheel, so you have the same airflow potential.

The difference is the turbine side, the HX40 will be slower spooling but have better WOT drive pressure. The HE351 will spool much better and could run higher drive pressure WOT and at upper rpms, it just depends on how you use it.

There are several OEM turbine sizes for the HX40, but they are all larger than the HE351 and the WG housing is 16cm if I recall. The turbine housing on the VE is variable from (from memory) ~3cm thru ~25cm, so even thou the turbine wheel is smaller the larger potential for the housing may negate any increased pressure.