gt42 What to do

[Norcaldrifter]

I actually have a 80mm inducer 108 exducer turbo with exactly a 1.32 ar. Might go back and measure the turbine wheel. Looks t6 flanged. How's that sound for the large turbo on a compound setup? It's a Garrett turbo but it's a detroit diesel series tv81127 I think.. I dismissed it since I thought it would cause see through block syndrome....

 

[ripmf666]

I actually have a 80mm inducer 108 exducer turbo with exactly a 1.32 ar. Might go back and measure the turbine wheel. Looks t6 flanged. How's that sound for the large turbo on a compound setup? It's a Garrett turbo but it's a detroit diesel series tv81127 I think.. I dismissed it since I thought it would cause see through block syndrome....

Well right off as a single lol. Post a pic of this turbo I'm not a fan of taking turbos right off combo like above because of the rpm difference are motors run at. Getting these setups that you think are saving money end up costing more in the long run.

 

[ripmf666]

I actually have a 80mm inducer 108 exducer turbo with exactly a 1.32 ar. Might go back and measure the turbine wheel. Looks t6 flanged. How's that sound for the large turbo on a compound setup? It's a Garrett turbo but it's a detroit diesel series tv81127 I think.. I dismissed it since I thought it would cause see through block syndrome....

So really you don't have a 4294 it's more of a gt4508
http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT45/GT4508R.htm

 

[Norcaldrifter]

So really you don't have a 4294 it's more of a gt4508
http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT45/GT4508R.htm

Ok I have a total of 4 turbos:
Turbo 1: airwerks s300sx 9179. It's a 66mm extended tip turbo. This turbo is on my race car and will not come off.
Turbo 2: gt4294 new sittin there no waste
gate. Didn't read the ar on the hot side.
Turbo3: the garrett 80mm inducer detroit diesel.
Turbo 4: blown gt4088. Could get a new chra but don't want too

 

[Righteyeblind]

Rebuild the 4088 and twin it to your 80mm charger. Or take your 366 off your racecar and twin that if its gated

 

[ripmf666]

Ok I have a total of 4 turbos:
Turbo 1: airwerks s300sx 9179. It's a 66mm extended tip turbo. This turbo is on my race car and will not come off.
Turbo 2: gt4294 new sittin there no waste
gate. Didn't read the ar on the hot side.
Turbo3: the garrett 80mm inducer detroit diesel.
Turbo 4: blown gt4088. Could get a new chra but don't want too

Rather post you have a gt4294 then say it's a 80mm in and 108 ex it makes everyone think your talking about the same turbo. Now we see were talking about more then one turbo so it helps because a 4294 is not a 80mm

 

[Norcaldrifter]

Rather post you have a gt4294 then say it's a 80mm in and 108 ex it makes everyone think your talking about the same turbo. Now we see were talking about more then one turbo so it helps because a 4294 is not a 80mm

I understand that. Im decent with turbo talk just not with diesels in relationship to power output. I know on a 2jz a gt4294 will make 750-800 :thumb: so i figured a 6.6l would make more. Why not use the stocker to twin the 80mm? And putting the 80mm on wont window the block? Ill take pics. I need a comp cover for the 80mm. Or I could put on the 4294 as a single and sell the other turbos. Im gathering the 4294 can max the Lb7 rods. I mean its bigger than stock by what 10mm? The origional reason for this thread was pertaining to the 4294 since I planned on putting it on as a single. I was starting to get discouraged from putting it on midway through the thread so I put all the cards on the table.The s366 isnt going anywere.
After digging a bit more I thnk the Kb7 can only do 550hp and then after that its on borrowed time. So my new goal I guess is around 500whp with the gt4294 unless it would be worth using the 80mm.

 

[Righteyeblind]

Your stocker can get you 500-525hp and into the 12's and some people have made it well into the 12's with a stocker. Good tuning from a good tuner is your friend. Bigger injector nozzles and your 4294 is going to give you your best shot at high 11's with what you have. Get some tunes from Rob (idahorob) or other good tuners. The problem with getting a ton of hp with the turbo you have is you're limited on fuel with the stock cp3. Fuel makes power in these trucks. If you have the biggest turbo in the world with no fuel you're not going to get anywhere.
These motors do really well on proper tuning. I have 171k miles on my truck with over 100 passes and half those are with 600hp or more. Fuel mods on my truck are stock cp3 with Wicked Diesel regulator and twins with a S475 being the big and stock being small.
I hope this helps you out and read a lot on this site because you can learn a lot.

 

[paint94979]

Your stocker can get you 500-525hp and into the 12's and some people have made it well into the 12's with a stocker. Good tuning from a good tuner is your friend. Bigger injector nozzles and your 4294 is going to give you your best shot at high 11's with what you have. Get some tunes from Rob (idahorob) or other good tuners. The problem with getting a ton of hp with the turbo you have is you're limited on fuel with the stock cp3. Fuel makes power in these trucks. If you have the biggest turbo in the world with no fuel you're not going to get anywhere.
These motors do really well on proper tuning. I have 171k miles on my truck with over 100 passes and half those are with 600hp or more. Fuel mods on my truck are stock cp3 with Wicked Diesel regulator and twins with a S475 being the big and stock being small.
I hope this helps you out and read a lot on this site because you can learn a lot.

Good to see you still around man:thumb:

 

[JoshH]

The GT4294 will flow just a hair more then a Gt4094 so with tuning and fuel low 12's.

The compressor map does show just a slight increase in overall air, but the turbine side in a GT42 will flow a ton better than a GT40. That should help free up quite a few ponies over the 4094.

High elevens are doable with 4294 and a single C, depending on the trucks weight and traction. I pulled off an 11.75 fuel only with a modded LB7 regulator, stock injectors and a GT4202 at around 6200 lbs. Trent ran an 11.6x with I think a single factory Cp3 and twins with a comparable race weight.

I agree. I would say with good tuning, low 12s shouldn't be much trouble, and with the right setup and a little luck, you should be able to get a high 11 out of it, especially with some weight reduction.

Rather post you have a gt4294 then say it's a 80mm in and 108 ex it makes everyone think your talking about the same turbo. Now we see were talking about more then one turbo so it helps because a 4294 is not a 80mm

Not everyone

 

[ripmf666]

I understand that. Im decent with turbo talk just not with diesels in relationship to power output. I know on a 2jz a gt4294 will make 750-800 :thumb: so i figured a 6.6l would make more. Why not use the stocker to twin the 80mm? And putting the 80mm on wont window the block? Ill take pics. I need a comp cover for the 80mm. Or I could put on the 4294 as a single and sell the other turbos. Im gathering the 4294 can max the Lb7 rods. I mean its bigger than stock by what 10mm? The origional reason for this thread was pertaining to the 4294 since I planned on putting it on as a single. I was starting to get discouraged from putting it on midway through the thread so I put all the cards on the table.The s366 isnt going anywere.
After digging a bit more I thnk the Kb7 can only do 550hp and then after that its on borrowed time. So my new goal I guess is around 500whp with the gt4294 unless it would be worth using the 80mm.

Lol so the gt4294 to be on the same page is a T4 and what ar is the exhaust side of it. Be best if it's a 1.00 housing.Be fine as a single.

On the 80 mm if the exhaust houding ar is in the 1.39 area and a T6 that will twin fine with the stocker.

 

[Norcaldrifter]

I'm not sure what the hot side is, I'm going to check. On a separate note, when lb7s are built do you lower the compression? Just wondering if the compression was lowered if it would breathe life into the stock rods for a bot more power. I think the lb7 runs 16:1 compression. What if I lowered it to say 15:1 or even 14:5:1. Would the engine still even work.

 

[maine04max]

lb7's have a 17.5 c/r iirc. cut stockers are in the 16 :1 area depending on how much they are cut . i dont think just adding a lower c/r will make the rods last

 

[Norcaldrifter]

lb7's have a 17.5 c/r iirc. cut stockers are in the 16 :1 area depending on how much they are cut . i dont think just adding a lower c/r will make the rods last

Yea, it's a just a thought. Works on gas engines.....

 

[ripmf666]

I'm not sure what the hot side is, I'm going to check. On a separate note, when lb7s are built do you lower the compression? Just wondering if the compression was lowered if it would breathe life into the stock rods for a bot more power. I think the lb7 runs 16:1 compression. What if I lowered it to say 15:1 or even 14:5:1. Would the engine still even work.

17.5 to 1 here is the specs for your motor at this link http://www.duramaxdiesels.com/forum/showthread.php?t=6136

if your taking the time to lower it in the dmax might as well add new rods when your in there.

 

[Norcaldrifter]

Well what about a thick headgasket with arp harware? For gasoline engines we put on thicker head gaskets to lower the compression ratio. Plus if I did tear down the engine, the billet rods are 3k in parts. I mean the cheapest way for me would be to either lower the compression through a spaced headgasket. Second would be shot peened lbz rods
with domed lb7 pistons.

 

[Noreaster]

So my new goal I guess is around 500whp with the gt4294 unless it would be worth using the 80mm.

You can do 500hp on the stock turbo

 

[Righteyeblind]

Good to see you still around man:thumb:

Yep still kicking. Just a little tougher now im up here and the racing season is only 3 months long haha! Makes for a long winter which means more time in the shop building the truck.

 

[JustinD]

Should be able to be better than 500 rwhp and mid 12's???? I have a stock turbo and went 12.72. Not sure how this turbo compares to a A5K but my buddy went 12.40 with an 04 LB7 with an A5K on his stock motor single CP3.

 

[ripmf666]

Well what about a thick headgasket with arp harware? For gasoline engines we put on thicker head gaskets to lower the compression ratio. Plus if I did tear down the engine, the billet rods are 3k in parts. I mean the cheapest way for me would be to either lower the compression through a spaced headgasket. Second would be shot peened lbz rods
with domed lb7 pistons.

There is no domed piston in a Duramax. Gassers yea we can get a thick gasket and cheat and lower the comp ratio but not as much of a drop on the diesel. And its still not going to save the rods you could lower your comp ratio to 15 to 1 or leave it were it is now and the rods are going to say good by to you when there tired.The LBZ rods are alittle stronger but not worth taking a motor thats running fine apart for and installing. If your doing that most will wait and spend the 2,600 for good rods and not have to play with it for awhile.
Here is a link to Gm Head Gaskets A is the stock gasket C is what most of us use on the rebuilds. Also there is alot of info in this are you might want to look around at.
http://www.duramaxdiesels.com/forum/showthread.php?t=6148