Changing to a larger compressor wheel? Diesel related.

[turbovanman²]

I know this is diesel related but the same principles should apply.

I have a bunch of different Holset wheels and of course, I can't leave well enough alone plus this is research for upgrading some of my customers trucks.

I currently have an HX35 on the van, with a 7 blade 54/78 wheel. I have an 8 blade 56/83 wheel and of course, the 351/40 wheel, 7 blade and 58.5/86.

Trying theory instead of swapping parts, lol. So at what point do you know or not know more air is good or bad?

Yes, I know about fuel and machining covers.

On my van, my drive pressures are good to around 10 psi, so if I can cram more air at 10 psi, then that saves me having to buy an expensive and hard to find larger turbine housing plus your increasing efficiency at lower boost? Correct?

[turbovanman²]

No one?

Well I know backpressure etc so I am going to put the 351 comp wheel on and see what happens, then put the HX40 on.

[bakes]

i can get into a bunch i idea but the one that sticks in my head all the time is you have to watch to EGTs on a diesel when raising boost you can lower your egts to low if you cant supply the fuel for that boost level

[Reaper1]

I'm not a diesel expert at all. I know the basic principles, and some of the things it takes to make power with them, but beyond that, they are somewhat different world. I wish I could comment helpfully, though!

[turbovanman²]

Theory is the same really. I think at low boost, the bigger wheel will make a nice upgrade without affecting drive pressures too much, but as the boost goes up, I would guess 15 psi, my drive pressures will go up a lot more. It will be a fun experiment, then the huge HX40 goes on, they are just perfect for our engines.

i can get into a bunch i idea but the one that sticks in my head all the time is you have to watch to EGTs on a diesel when raising boost you can lower your egts to low if you cant supply the fuel for that boost level

Yep, right now, egts are well below limits, adding more air without fuel will lower EGT's. With diesels, fuel equals EGT's, backwards to gas engines.

[Shadow]

I know this is diesel related but the same principles should apply.

I have a bunch of different Holset wheels and of course, I can't leave well enough alone plus this is research for upgrading some of my customers trucks.

I currently have an HX35 on the van, with a 7 blade 54/78 wheel. I have an 8 blade 56/83 wheel and of course, the 351/40 wheel, 7 blade and 58.5/86.

Trying theory instead of swapping parts, lol. So at what point do you know or not know more air is good or bad?

Yes, I know about fuel and machining covers.

On my van, my drive pressures are good to around 10 psi, so if I can cram more air at 10 psi, then that saves me having to buy an expensive and hard to find larger turbine housing plus your increasing efficiency at lower boost? Correct?

Is this on a diesel van as in "diesel relayed" like your title says? Or is this on your TIII van?

When you say your drive pressures are Good, what are you considering "Good"?

[bgbmxer]

Diesels are not that hard after messing with my turbo diesel rabbit. If you are adding more air without fuel your power might not go up all that much honestly. But with a bigger setup you should be able to throw more fuel of that's what your looking to do. I ran my wastegate pretty much stuck closed because I only had enough fuel on the stock pump to get me into the 28psi range. Like some of the others have said excess fuel that isn't being burnt will just make higher egts and you can either crank the boost up to lower them or back the fuel off. All in what you want to do.

[Kryp2nitE]

Is 10-15 psi a normal level of boost for a 6.2?

[turbovanman²]

Is this on a diesel van as in "diesel relayed" like your title says? Or is this on your TIII van?

When you say your drive pressures are Good, what are you considering "Good"?

Correct, diesel related as in my diesel van.

Drive pressures are close to 1:1 up until 15 psi. Cruising is 5/7, part throttle/wot nets 10psi and 13 psi DP, WOT 20/28 dp.

Diesels are not that hard after messing with my turbo diesel rabbit. If you are adding more air without fuel your power might not go up all that much honestly. But with a bigger setup you should be able to throw more fuel of that's what your looking to do. I ran my wastegate pretty much stuck closed because I only had enough fuel on the stock pump to get me into the 28psi range. Like some of the others have said excess fuel that isn't being burnt will just make higher egts and you can either crank the boost up to lower them or back the fuel off. All in what you want to do.

I know, just playing around, I have the fuel, just playing air for now, she's pretty snappy for 10 psi, don't want to go over 15 psi.

Is 10-15 psi a normal level of boost for a 6.2?

6.2's aren't really rated for a turbo as they never came turbo. They consider 15 psi and 1100 EGT's the max but many have run over that with no issues. I currently run 15 psi and 1000 egt's when going up a stupid steep hill.

[Kryp2nitE]

6.2's aren't really rated for a turbo as they never came turbo. They consider 15 psi and 1100 EGT's the max but many have run over that with no issues. I currently run 15 psi and 1000 egt's when going up a stupid steep hill.

You learn something new everyday , didnt know they were naturally aspirated.

[Shadow]

On my van, my drive pressures are good to around 10 psi, so if I can cram more air at 10 psi, then that saves me having to buy an expensive and hard to find larger turbine housing plus your increasing efficiency at lower boost? Correct?

If you put a larger compressor wheel on to "cram" more air in at 10psi your drive pr at 10psi should go UP. If you put a larger turbine housing on the existing turbo, drive pr should go DOWN.

Are you trying to go UP or DOWN in drive pr @10psi? BTW there's nothing wrong with 20/28 pr dif. There are very few turbo systems out there that actually achieve 1:1 as it has a lot more to do with the entire system and Not just the turbo.

[turbovanman²]

If you put a larger compressor wheel on to "cram" more air in at 10psi your drive pr at 10psi should go UP. If you put a larger turbine housing on the existing turbo, drive pr should go DOWN.

Are you trying to go UP or DOWN in drive pr @10psi? BTW there's nothing wrong with 20/28 pr dif. There are very few turbo systems out there that actually achieve 1:1 as it has a lot more to do with the entire system and Not just the turbo.

Correct, trying to get more air in at a lower boost, I don't mind if drive pressures go up a bit, if they get too high, it hurts our head gaskets. It will be interesting to see the results, going from the 7 blade HX35 wheel to the 351 wheel. I know I need to change the turbine housing but this is a cheaper route.

[bgbmxer]

My diesel was NA also and I threw the boost to it and it loved it. Did some mods to the head intake and exhaust tho. And ran a mitsu off and old caravan which no one said would spool on the forums but it did and would prolly try a Garrett next time. My point is I had a big intercooler and just like you watched my egts. I think you would be safe to run plenty more boost. I ran out of fuel and the clutch didn't like that I doubled the power output either.

[turbovanman²]

My diesel was NA also and I threw the boost to it and it loved it. Did some mods to the head intake and exhaust tho. And ran a mitsu off and old caravan which no one said would spool on the forums but it did and would prolly try a Garrett next time. My point is I had a big intercooler and just like you watched my egts. I think you would be safe to run plenty more boost. I ran out of fuel and the clutch didn't like that I doubled the power output either.

What engine? A Honda can spool a Mitsu,

I can turn the fuel up but waiting, its a pain to do.

[bgbmxer]

What engine? A Honda can spool a Mitsu,

I can turn the fuel up but waiting, its a pain to do.

the old vw 1.6. And yea Hondas have way better head flow than the vw did back then. Everyone on the forums said it wouldn't spool. Vw that is. It spooled way earlier then I thought it would and think the Garrett off are cars would have been perfect.

[turbovanman²]

the old vw 1.6. And yea Hondas have way better head flow than the vw did back then. Everyone on the forums said it wouldn't spool. Vw that is. It spooled way earlier then I thought it would and think the Garrett off are cars would have been perfect.

Nice, and yeah, a Garrett would have probably worked great.