GM 6.5 Diesel turbo ok for a built 350?

[turbovanman²]

A friend has a good used BW turbo and wants to turbo his built 350 Nova, how will this work. I know the turbine is large so any info?????

[WickedShelby88]

I think the 350 like something more like a GN style turbo.

[JeremyL]

more like a pair of GN turbos.

I can't remember what size those 6.5 diesel pieces are, but I'd bet you'd be better off with two of them.

[turbovanman²]

more like a pair of GN turbos.

I can't remember what size those 6.5 diesel pieces are, but I'd bet you'd be better off with two of them.

They flow alot of air, I believe there similiar to a Holset HX35 if memory serves. The turbine housing is rather large though so they might take awhile to spool or not?

[JeremyL]

If you'll get me the model number, I'll see if I've got a compressor map & some info on it somewhere.

[Aries_Turbo]

turbine housing may be large but the compressor will be small... prolly not that different than a mitsu compressor with a garrett T3 size turbine on a 2.5L. if its the size of a HX35 or something like a 50 trim, youll want two of them on a V8. a 350 is 2X 2.85L 4-bangers. since we deal alot with 4-bangers, think of it that way and it will make more sense the compressor size youll need.

Brian

[turbovanman²]

If you'll get me the model number, I'll see if I've got a compressor map & some info on it somewhere.

GM 1 thru 8 should work, there all the same specs, just different housings.


turbine housing may be large but the compressor will be small... prolly not that different than a mitsu compressor with a garrett T3 size turbine on a 2.5L. if its the size of a HX35 or something like a 50 trim, youll want two of them on a V8. a 350 is 2X 2.85L 4-bangers. since we deal alot with 4-bangers, think of it that way and it will make more sense the compressor size youll need.

Brian


Ok, but one of these will produce 10 psi on a 6.5L aka 400 cid so thats whats messing me up for sizing.

[Aries_Turbo]

the exhaust housing is pretty large to keep it from choking off all the flow. the compressor is large enough to make decent boost on the motor, but when you are talking about a "built" 350 thats going for performance, you want more compressor size... I mean the exhaust side might be fine for the 350 but id put something like a T76 wheel in the compressor housing. look at ash's twin turbo 355... two large turbos. feets' 440 belvidere.... two hybrids. for a large gas motor, you want more turbo... especially in the compressor side.

Brian

[turbovanman²]

Ok, understood.

Now he just wants a few psi of boost, nothing stupid so based on what you've said and the 6.5, I think it would be ok, what do you think?

[Aries_Turbo]

wait a min.... DUUUUUUHHHHH! I forgot the biggest reason. RPM! whats the diesel rev to... 4000rpm max usually (unless its a VW TDI). there is much less airflow down there.

get the map and compare it to whats in franks calculator.

i still think it will be too small. i mean alot of those turbos are good for 400-500hp. a 350 with a set of heads and a cam makes 400hp with its eyes closed (assuming the builder isnt an idiot)... its most likely going to be too small.

Brian

[JeremyL]

GM 1 thru 8 should work, there all the same specs, just different housings.



Little snippets that I've collected from various places & dug out of my archives earlier. It's hard to find any solid info on them other than that it's a IHI RHC6 :


There's a little difference in the wheels on some of them, and the wastegate/exhaust housing is a little different on the 8. the 8 is an upgrade for all of them, but 3 & 4 should be the same, but the wheel trim in a 5 is different according to my info.

The IHI RHC6 GM8 measures 2.756" major diameter and 1.968" minor diameter on the compressor wheel. There are NO minor diameters of TO4E that measure 1.968". The closest you would get would be the TO4E 40 trim which measures 1.870"...BUT..the major diameter is 2.950". A difference of a finger nail on each side...quite a difference in percentage and overall flow potential.


As far as the turbine, the GM8 measures 2.420" major and 2.030" minor. GM3 appears to be somewhat larger on both the compressor and minor turbine wheel. GM3 measures 2.150" minor on the turbine wheel.
The GM3 has a cold trim of 53 and a hot trim of 79. Any of them should top out at 620 CFM of air.

A GM-4 specs are .60 A/R turbine / .70 A/R compressor w/46 trim.

The only maps I have came from here.. and they're for current models but are supposed to be similar.

http://www.ihi-turbo.com/turbo-chart6.gif

http://www.ihi-turbo.com/turbo-chart8.gif

Single turbo should be good to 350 - 400 hp, twins to 700.

[turbovanman²]

Thats great info thanks.

So basically, there a T3/T4 hybrid with a slightly larger turbine wheel. Hmmmm.

[JeremyL]

Thats great info thanks.

So basically, there a T3/T4 hybrid with a slightly larger turbine wheel. Hmmmm.

Exactly.

[RoadWarrior222]

I guess 'coz diesels run with excess air it would be set up for higher volume/less pressure to get it spooling. Sounds like it would work best on a 6 cyl gasser.

[turbovanman²]

So what would you say the turbine wheel is? I wanted to use my 50 trim T3/T4 with a stage 3 wheel/.63 housing on my 6.2 but was told it would choke the engine.

[Aries_Turbo]

simon, it might be ok..... given the RPM thing that I forgot about. the issue will be the restrictive exhaust side with yours though. it makes the EGT's hotter.

just get a used HX35 or 40 and put it on there. :)

better yet, leave it alone, you have enough to do. :)

Brian

[turbovanman²]

simon, it might be ok..... given the RPM thing that I forgot about. the issue will be the restrictive exhaust side with yours though. it makes the EGT's hotter.

just get a used HX35 or 40 and put it on there. :)

better yet, leave it alone, you have enough to do. :)

Brian

Hahaha, yeah, I have to V8 my 98 Jimmy and I need to turbo the van for next year, getting a Toy Trailer, :D

[JeremyL]

What's the max RPM on a 6.2? 34 - 3500? I don't think it'd be too much of a restriction, and any extra air you force into there is gonna make a difference in power.

I've still got my 6.9 powered Ford stored back in Texas, and for several years I've kicked around the idea of putting twin T3s on it. Yeah, I know they make a turbo kit for them for about 1400 bucks, but I think it'd be kick --- to pop the hood & see a turbo sitting on each side tucked about where the factory battery locations are.

[turbovanman²]

What's the max RPM on a 6.2? 34 - 3500? I don't think it'd be too much of a restriction, and any extra air you force into there is gonna make a difference in power.

.

3000 rpm or thereabouts.

Yeah, stock form, 10 psi is max using the GM turbo's.

[Aries_Turbo]

yeah i guess youd be fine then simon. what turbo are you gonna use on the van then?

Brian

[turbovanman²]

yeah i guess youd be fine then simon. what turbo are you gonna use on the van then?

Brian

Well this turbo is for a buds car, mine is getting the turbo Chris Ramsdell traded me, :thumb:

[Aries_Turbo]

ahhh, what turbo is that. I remember hearing about it a little but I forget what it is. :)

Brian

[turbovanman²]

ahhh, what turbo is that. I remember hearing about it a little but I forget what it is. :)

Brian

Check out my thread, not sure if its in this section or other turbo vehicles, ;)

[Aries_Turbo]

you bum... you could just put down the 5 numbers/letter combination lol

[turbovanman²]

you bum... you could just put down the 5 numbers/letter combination lol

Whattttttt? :p

[Aries_Turbo]

the turbo description!

[turbovanman²]

the turbo description!

I don't know what it is, can't remember, :o

[Aries_Turbo]

hahahahaha! thats funny. :) ok I'll look ;)

which thread is it in?

[turbovanman²]

Right under your nose, :p

http://www.turbo-mopar.com/forums/showthread.php?t=15006

[Aries_Turbo]

oh that thread lol. you need your common thread links in your sig ;)

Brian

[Mopar_Nutz]

Actually it is a bit misleading for a guy with 11,000 posts to simply say "check my thread" :p

[Turbodave]

Actually it is a bit misleading for a guy with 11,000 posts to simply say "check my thread" :p

:amen: :lol:

[Aries_Turbo]

thats what I was thinking too! dang simon! ;)

Brian

[Vigo]

yeh diesel turbos throw everyone off so bad because of the rpm and VE thing.

diesels rev low, and they are at WAY less VE at max rpm then the same rpm in a gas motor. thats why stock turbos on diesels twice the displacement size up pretty good on a good breathing gas motor half the size and twice the rpm.

but yeh for a decent small block turbo you either need one BIG one or two of them about the size of our t2 garretts at minimum and even that is a severe choke on the exhaust side.