Looking for advice on compound turbos

[co04cobra]

My current turbo specs are Garrett-Volvo Gt4594
68X94 Comp 88X82 1.19 housing and is a t-6 setup.

Reason for the compound is Im gear bound when sled pulling. I can't get it off the line and spooled in 3rd and run out of rpms half way up the track in 2nd. Also, wouldnt mind a little quicker spool on the street, but overall it does excellent as a DD.

This turbo has been good for 650hp+ on the dyno, and has always done very good sled pulling and towing.

My big ? is. Is this turbo to small to be a LP turbo? I wouldnt mind losing a little top end power to broaden out the power band. Do you guys have any suggestions for a turbo that might work with this setup and be a HP? Is it even possible using this setup? Please excuse my ignorance on this subject. This is something I have never tried or worked on before.

 

[TyCorr]

My current turbo specs are Garrett-Volvo Gt4594
68X94 Comp 88X82 1.19 housing and is a t-6 setup.

Reason for the compound is Im gear bound when sled pulling. I can't get it off the line and spooled in 3rd and run out of rpms half way up the track in 2nd. Also, wouldnt mind a little quicker spool on the street, but overall it does excellent as a DD.

This turbo has been good for 650hp+ on the dyno, and has always done very good sled pulling and towing.

My big ? is. Is this turbo to small to be a LP turbo? I wouldnt mind losing a little top end power to broaden out the power band. Do you guys have any suggestions for a turbo that might work with this setup and be a HP? Is it even possible using this setup? Please excuse my ignorance on this subject. This is something I have never tried or worked on before.

Just based on what most compounds use, not.just on the 7-3, it's too small. Need a 47 or larger atmosphere. You can do just about anything though. You could run a s366 or 362 and probably have to gate em both. You would retain whatever you already have and gain a little bit more up top. Your real windfall would be low rpm deliverability as the hp will be on most of the time so it'll mitigate the lag in the gt45. So what I'm saying is you wouldn't fall under the charger anymore pulling.

 

[co04cobra]

Just based on what most compounds use, not.just on the 7-3, it's too small. Need a 47 or larger atmosphere. You can do just about anything though. You could run a s366 or 362 and probably have to gate em both. You would retain whatever you already have and gain a little bit more up top. Your real windfall would be low rpm deliverability as the hp will be on most of the time so it'll mitigate the lag in the gt45. So what I'm saying is you wouldn't fall under the charger anymore pulling.

I was assuming I would need to gate them. Which does lead to another ?. It seems like finding the right gate and getting it setup is very time consuming? Or maybe somewhat of a guessing game? S366 seems like it could work. Possible to do a ball bearing or billet setup with the HP to help increase spool more?

 

[TyCorr]

I was assuming I would need to gate them. Which does lead to another ?. It seems like finding the right gate and getting it setup is very time consuming? Or maybe somewhat of a guessing game? S366 seems like it could work. Possible to do a ball bearing or billet setup with the HP to help increase spool more?

Yea. 38r is bb. I'm not sure who else makes a bb turbo that size. You might not need a gate if you could.get a loose housing on that 45 but it's a long shot. I think that lp would be too small. It'd spool quick but up top I'm not sure.

 

[dentexpowerstroke]

I know someone on here ran a 38r and a gt45.

 

[silverpsd_06]

I think you would be better off getting a 1.0 t4 housing for that 4594 and running that as your secondary then getting something bigger to put in front of it.. Whichever you do do not be shy about Wastegates the bigger the better. Your only going to flow as much as that 94 will allow you wouldn't really be gaining anything using it as a primary.

 

[MadDiesel73]

^^ x2 and get a 88+mm atmo

 

[silverpsd_06]

I bet you would be suprised how well it would run with a 1.0 t4 on it it should start to come alive right around 1800 and if you went with a 4788 it will be right behind it starting at around 2100.... My compound setup is a gt4094r with a big ass precision 106mm in front of it, the atmosphere was coming right up with the secondary as soon as you built ten pounds of boost then it was hang on to your ass.

Id just get a 66mm gate and a t4 housing a gt4788 and call it a day...

 

[MadDiesel73]

And billet rods if u dont already

 

[co04cobra]

Yea. 38r is bb. I'm not sure who else makes a bb turbo that size. You might not need a gate if you could.get a loose housing on that 45 but it's a long shot. I think that lp would be too small. It'd spool quick but up top I'm not sure.

I think my buddy that built this kit still has a 1.27 for this turbo. I'm sure I could benefit the most from running a gate, but I would be completely lost on setting it up.

 

[co04cobra]

I think you would be better off getting a 1.0 t4 housing for that 4594 and running that as your secondary then getting something bigger to put in front of it.. Whichever you do do not be shy about Wastegates the bigger the better. Your only going to flow as much as that 94 will allow you wouldn't really be gaining anything using it as a primary.

Yea that was kind of my original plan. Current setup starts to spool at 1700. Im not really looking to have a big increase in top end. Just would like to be able to get off the line in 3rd or at times not down shift when on the road.

I do have a swamps BFH and Hypermax setup here. I actually am a little unsure of the exact specs of their turbo.

 

[silverpsd_06]

I think the BFH is around a 75mil probably comparable to a s475 in some respects.. Still a little too small in my opinion, And i know your pain driving a six speed with larger injectors and turbo thats why i went to compounds. Besides a 38r what you have is probably one of the quicker spooling turbos for these trucks at least being a garrett. You could sell 4594 and get a 38r then put an atmosphere in front of it?

 

[JD3020]

What class are you pulling in where compounds are allowed? Here if you want to run compounds you need, well something like this. LOL

 

[TyCorr]

I bet you would be suprised how well it would run with a 1.0 t4 on it it should start to come alive right around 1800 and if you went with a 4788 it will be right behind it starting at around 2100.... My compound setup is a gt4094r with a big ass precision 106mm in front of it, the atmosphere was coming right up with the secondary as soon as you built ten pounds of boost then it was hang on to your ass.

Id just get a 66mm gate and a t4 housing a gt4788 and call it a day...

Hat sounds bad ass Scott!

 

[TyCorr]

What class are you pulling in where compounds are allowed? Here if you want to run compounds you need, well something like this. LOL

Most of the broke dick pulls we have here,you run what you brung. Thing is, the guy who won the last one I went to was running a 00 with a p7100 pumped 24v and compounds. Second place was my cousins 08 6.7 with tuning and a sb clutch. He was within 5 feet of the mechanical truck. I was only afoot behind him with stg IIs and a 38r on 35s. It's not that organized. I was surprised how nice the sled was. I decided my truck isn't real setup for that! LOL

 

[co04cobra]

I think the BFH is around a 75mil probably comparable to a s475 in some respects.. Still a little too small in my opinion, And i know your pain driving a six speed with larger injectors and turbo thats why i went to compounds. Besides a 38r what you have is probably one of the quicker spooling turbos for these trucks at least being a garrett. You could sell 4594 and get a 38r then put an atmosphere in front of it?

Wouldnt using the 38r be a step back? I would just use this turbo as the HP I think before I would do that. I really like my current mount setup is one of the reasons I was considering doing it this way. What would I be looking at using a s366 like Ty had suggested? Way to high of BP? Overspinning the 366?

Yea the brush pulls are just run what you brung. I do not have the time to be dedicated to a points series.

 

[MadDiesel73]

I would do a 467 if u switch to a borg hp.

 

[TyCorr]

Wouldnt using the 38r be a step back? I would just use this turbo as the HP I think before I would do that. I really like my current mount setup is one of the reasons I was considering doing it this way. What would I be looking at using a s366 like Ty had suggested? Way to high of BP? Overspinning the 366?

Yea the brush pulls are just run what you brung. I do not have the time to be dedicated to a points series.

You aren't gonna be running the 38r, 366,or your gt40 at the same boost levels as you would as a single. Gotta remember 20psi out of your hp is probably 60psi total, on th manifold. If you run that gt40 up to 40# you'll blow that motor apart. A smaller charger would be more responsive and also be working in its sweet spot for where your 7.3 is going to be at.

 

[co04cobra]

Ok sorry if Im still somewhat confused. It sounds like you think that I may be able to use the 366, gt40, or evey a 38r to feed my current turbo?


On another ? lets say I leave my current turbo as a HP. What could I use for a LP. You guys still think that with this housing I will still have the same lag?

 

[MadDiesel73]

If u keep your current turbo get a smaller 1.0 t4 to spool it. Then get a gt4788 1.25 t6 or larger for the top end.

You could use a 366/38r/s467 as the hp for even better spooling.

Your gt45 is too small the be an effective lp