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HX40II Turbo Install

Tim writ:


Is there actually a specific tune for the HX? Sorry if I missed that tid bit. I know ATT has a specific tune.

Right now I run the Heath GL4 tune and know that there is more potential in the tune for the HX. Honestly I was just thinking about getting the ATT tune which would be close IMO.

Also to add. I run the stock HX with the 20 PSI valve, no problems at about 15K. But I drive easy, very rarely over 14PSI. And when towing I just regulate by left foot for Pyro and Boost.

I'm headed to Orlando next week with the trailer, so I should bring back some good MPG numbers when towing on the HX.


AFIK there are some tunes for the OBD-I HXs, I do not believe Bill has done any tweaking for the HX it was like pulling teeth to get him to tweak for the ATT, as far as the ATT being close to the HX if the "unbiased tester" is to be believed, apparently the tune is not close enough the HX tune used would not spool the ATT properly but works for the HX
 
How does it 'monitor' boost pressure for opening and closing? From what I see, the spring is simply pushing the wastegate flap against force produced by the pressure of the exhaust. I am guessing the exhause pressure is directly attributed to the intake pressure?

Is one system more reliable than the other? I do not want to accidentally overboost my old girl. I don't think my 265,000+ mile engine can handle overboost. I just want to be able to maintain boost beyond 2000 rpm with less heat.


I had 2 gauges installed 1 permanently installed for boost, and a second tapped to the right bank collector just below the turbo entry to monitor the backpressure/drive pressure, with GM turbo once approaching 10 psi boost the back pressure with the GM waste gated turbo starts driving 2x the more into boost you go, I saw 50psi for 17 psi boost, just the nature of a WG turbo, which is why the large turbo without a WG is so attractive especially to a vehicle used as a hauler, you get plenty of boost/lower EGT/less stress, well within design envelope of the GM engine design.

It would be interesting to see the drive pressure numbers at various speeds/loads for the HX turbos similar to what I documented for the ATT.
 
'Its a Bill Heath, Max E Tork with a few tweeks'

Post 52 Raceday states the following. I got the impression that these are tweaks that Raceday requested. What this actually means in regards to a HX tune well......... I guess ask Bill or Raceday.

Cheers
Nobby
 
LOL, I guess that gets little bit closer to nowhere then on an OBD-II HX tune.

Granted I still think the HX and ATT tunes would be fine for interchangibility. Both breathe so much better than the GM-8, with the right other mods of course like exhaust, crossover, and intake.

My only complaint so far is that with the HX if you are starting a grade you has better keep the boost up above 5-7 PSI or you will loose momentum / heat up the Pyro. Just like any diesel you actually need the boost to keep it cool.

... I still need to do the FTB mod, which I have, but have not installed as I suspect I run out of fuel on long grades. This winter once life settles down it will be done. :)

Thanks again guys!!!
 
I had 2 gauges installed 1 permanently installed for boost, and a second tapped to the right bank collector just below the turbo entry to monitor the backpressure/drive pressure, with GM turbo once approaching 10 psi boost the back pressure with the GM waste gated turbo starts driving 2x the more into boost you go, I saw 50psi for 17 psi boost, just the nature of a WG turbo, which is why the large turbo without a WG is so attractive especially to a vehicle used as a hauler, you get plenty of boost/lower EGT/less stress, well within design envelope of the GM engine design.


It would be interesting to see the drive pressure numbers at various speeds/loads for the HX turbos similar to what I documented for the ATT.

To lump all wastegated turbos with the stock wastegated is utter failure. Properly sized wastegated turbos are much closer to 1-1 drive .....
 
... I still need to do the FTB mod, which I have, but have not installed as I suspect I run out of fuel on long grades. This winter once life settles down it will be done. :)

Thanks again guys!!!
That is a must do IMO; before going with that mod I was always falling off in the power band I would flat stop gaining momentum.
 
'Its a Bill Heath, Max E Tork with a few tweeks'

Post 52 Raceday states the following. I got the impression that these are tweaks that Raceday requested. What this actually means in regards to a HX tune well......... I guess ask Bill or Raceday.

Cheers
Nobby

Thanks Nobby I missed that, Max E was what I was running before HP4 and I'm on like HP10 now :) even though Bill did not assign a number to program I'm running now.
 
Any more development on the HX tune yet? What is Raceday running? I still plan to do this with the HX35W I found. It is prioritized behind a couple other 'more important' things around here but I still plan to do it.
 
Some pics of my install, still have some details to tend to (finding a better spring is one) but the burb loves it, the engine sounds much more relaxed, and when i get on it, its all go! Spools quick, no black smoke and lower EGT's.

29qb3bp.jpg

212711x.jpg

10zybyb.jpg

2wok3o3.jpg

2qj9080.jpg
 
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