Compound Turbo Setup for 1,500whp

[nskyline34]

Hey guys, looking for a little advice on turbo sizes - but this application is a little different than the norm.

Its for a land speed record vehicle at Bonneville I'm piecing back together. I'm looking for a compound setup that will make about 1,500whp and be reasonably quick to spool. (I cannot have a sled pulling type of setup that can be spooled on the line for 10 seconds). We have the capability to fuel to about 2,000hp, so dont worry about the fueling side - we can make it work. I'm mainly wondering about the air. I was going to order a GTX5544R and a GTX4202R, or something like an S475 with a diverter valve? I'm always nervous and second guess myself when picking out compounds. I'm not sure if anyone has ever run a diverter valve compounds - and how well (or poorly) its worked? I'm positive someone has tried it, but I'm I dont think I've ever seen any results on how it worked?

Anyone on here have first hand experience with a setup like this or similar to it?

 

[Chevy1925]

whats your RPM range? whats done to the heads/cam?

have you considered how spool up will be different since you will be rolling into it from the start and not boost launching?

 

[duramaxzak]

You would probably be better off doing triples.

 

[2004LB7]

Would you be able to spray to make up for spooling?

 

[Bdsankey]

I don’t see why a dual Garrett setup won’t do what you’re after. The Garrett’s offer better response over a comparable borg but are double the cost typically. Another solid option would be a 472-476 with 87 turbine in the valley and a GT55 over the top. The S400 in the valley will still spool/drive well and also offer some cost saving/user rebuildability.

 

[nskyline34]

whats your RPM range? whats done to the heads/cam?

have you considered how spool up will be different since you will be rolling into it from the start and not boost launching?

SoCal heads for now, but have a couple set of Edelbrocks on the way. Cam I do not recall off the top of my head - custom grind though.

We push to about 70 and then I will slip the clutch a little when coming off the push truck, but mainly I need it to spool semi quickly because of managing wheel spin. When I have to pedal it (which I have to) I dont want to have to wait forever for it to respool again. This definitely isnt like a drag strip or sled pulling. Until about 150 when aerodynamics help, I have about the same amount of grip as a nicely packed gravel driveway...so not a lot! lol

You would probably be better off doing triples.

Agreed - but absolutely zero room.

Would you be able to spray to make up for spooling?

Can we - yes. However I would really like to avoid using the giggle gas at all. I'd like to get a setup that "works pretty good" and then when using the giggle gas "it works amazingly well!" Also remember that I have a little longer track than a drag strip and I'll basically be WOT for about 80 seconds...so that'd be a lot of spray! lol

I don’t see why a dual Garrett setup won’t do what you’re after. The Garrett’s offer better response over a comparable borg but are double the cost typically. Another solid option would be a 472-476 with 87 turbine in the valley and a GT55 over the top. The S400 in the valley will still spool/drive well and also offer some cost saving/user rebuildability.

I was thinking about a S475 with a GT5544, or I was thinking about a 4202 with a GT5544. I never considered the 83 or 87mm turbine on it though - really good idea.

All of my experience has been with BW turbos - how much faster does a GTX spool in comparison? Say if a BW starts to spool at 2k rpm, would a garrett start to spool at 1800? or would it start at the same rpm, but it would get to full boost faster? One thought I had was to find a setup that works "pretty well" with BW turbos, and then buy Garrett's because then it should spool really well.

 

[Bdsankey]

I was thinking about a S475 with a GT5544, or I was thinking about a 4202 with a GT5544. I never considered the 83 or 87mm turbine on it though - really good idea.

All of my experience has been with BW turbos - how much faster does a GTX spool in comparison? Say if a BW starts to spool at 2k rpm, would a garrett start to spool at 1800? or would it start at the same rpm, but it would get to full boost faster? One thought I had was to find a setup that works "pretty well" with BW turbos, and then buy Garrett's because then it should spool really well.

Richard Coker's setup (472/491) honestly spools quite well and appears to have some left in the tank. Both of his chargers are from Forced Inductions. After watching that truck compete in Diesel Power Challenge first hand as well as following him in the driving portions I would not hesitate to run that compound setup on my own truck. The Garretts, size for size, spool a few hundred rpm quicker than a comparable Borg unit. Jose @ Forced Inductions told me if I went to his GTR85 (85mm ball bearing Garrett) that I would have no loss in driveability to what I have now but also be able to make 1400-1500hp on fuel only.

 

[Chevy1925]

1500hp on a 472/491 is asking for high EGT's imho.

id rather see more air than fuel at that hp to keep EGT's down and help the engine last under WOT for the extended time they run.

i will say, the s483/GTX5544 combo we ran on the race cummins ran VERY cool EGT wise at 1700hp. But unless you are running a good cam to match some highly ported heads and run rpm in the 3k and up range, its going to be laggy on the 483. we spooled this very well at elevation on a 2500 stall converter but ran a D&J stg 3 6.7 head. rev limiter was at 5500rpm and it kept pulling hard to it.

id look at a 480 min under the 5544 to keep it flowing well but still spool. You will just need to get the rest of the engine flowing some CFM to make it worth while.

 

[Bdsankey]

1500hp on a 472/491 is asking for high EGT's imho.

id rather see more air than fuel at that hp to keep EGT's down and help the engine last under WOT for the extended time they run.

i will say, the s483/GTX5544 combo we ran on the race cummins ran VERY cool EGT wise at 1700hp. But unless you are running a good cam to match some highly ported heads and run rpm in the 3k and up range, its going to be laggy on the 483. we spooled this very well at elevation on a 2500 stall converter but ran a D&J stg 3 6.7 head. rev limiter was at 5500rpm and it kept pulling hard to it.

id look at a 480 min under the 5544 to keep it flowing well. You will just need to get the rest of the engine flowing some CFM to make it worth while.

I agree on the 72/91 setup, was more of a generalization that I believe it can be done with a Borg in the valley. Gotta love the way a Cummins spools turbos compared to a Duramax, makes me sad sometimes.

 

[Chevy1925]

I agree on the 72/91 setup, was more of a generalization that I believe it can be done with a Borg in the valley. Gotta love the way a Cummins spools turbos compared to a Duramax, makes me sad sometimes.

ive seen a few duramax's spool just as well. its all about CFM into the cylinders and out.

 

[JoshH]

A setup that spools quick and makes 1500 HP with low enough EGTs to keep from melting the motor down on a land speed run is going to be tough to come by. If you throw some nitrous on it, you can use it to help bring the turbos up without sacrificing flow on either end of the turbo. We need to know for sure what sort of RPM you plan to run because that is going to determine what size turbine wheel and housing will work best for your setup. A smaller turbine will spool quicker but will choke out in the higher RPM range and cause EGTs to start creeping up as well as higher drive pressure. I know on Richard's setup, drive pressure stays at or below boost until the RPM starts creeping up closer to 4500. Regardless of what setup you run, your exhaust temps are going to be higher than what most people are comfortable with in a street application, but as long as your cooling system is up to the task and your engine is built right, there shouldn't be too much of an issue. Higher HP requires more fuel which creates more heat, and that heat has to go somewhere.

 

[Ne-max]

A 72/91 isnt going to make a true 1500hp without a shit ton of nos. Find a dyno with a 30% correction factor maybe.

 

[Bdsankey]

A 72/91 isnt going to make a true 1500hp without a shit ton of nos. Find a dyno with a 30% correction factor maybe.

I'm not saying it will sustained. I'm am implying he doesn't need to go to the worlds largest compound setup to reach his goal. As I stated earlier, my reference was a generalization to the point of being able to still maintain the manners he is looking for while utilizing a Borg in the valley. I don't think there is any other solution than a GTX5544 as an atmoshperic charger (besides triples, which they don't have the room for) and still maintain some form of decent response. There is a massive difference between making a 2-5 second dyno pull/10 second pass vs 80 seconds flat out. Short duration allows for us to get away with things, not going for over a minute at a time.

 

[TheBac]

Wouldnt you guys just go back to Pat's setup for Casper's Bonneville run and modify it from there? IIRC, wasnt he just running a big single?

 

[nskyline34]

Thanks for all of the great info guys! One thing to keep in mind that I completely spaced on is that Bonneville is at 5500' - not exactly the most dense air that's for sure.

Unfortunately a Cummins is definitely capable of spooling things better than a duramax - that said I'm not going to allow that to limit us! haha

RPM wise we are capable of 6k, but I'm only planning on using about 5k upto maybe 5500 though. Once we have proven things, worked out the bugs, and I know how it will respond - then we will make some hero passes.

As for high EGT's I've got water injection to help - that said water will only go so far to cool EGT's and there's only so much of it.

Sounds like a 5544 is the way to go. Based on the math and PR's I'm thinking that we will need at a minimum a GTX4088, but this will be really pushing the limits on what it can do because I will need it around a PR of about 3.5 out of it which is approaching the limits of it's compressor map. Otherwise a GTX4202 (or a BW similar to turbo for testing and then I'll grab a GTX once we're sure).

Do people DD a truck with a GTX4202? (The reason I ask is because if someone is willing to daily it, then it probably has good enough manners for me to deal with on the salt.)

Bdsankey is correct - a quick blast down the strip or a short 300' pull is one thing, you can get away with 1800-2k EGT's...we've tried that...and melted the front half of the engine...and I dont just mean pistons - cylinder heads too.

 

[gmduramax]

A GTX4202 is very streetable

 

[JoshH]

I don't think a 4202 has enough turbine unless you gate around it a lot. I think a 4709 would work better for your power level. With a pusher vehicle, spooling on the line isn't as much of an issue as it is in drag racing or sled pulling. Most people have trouble building RPM under load to get the turbos lit, with a vehicle helping you get there, as long as you use your RPM, you shouldn't have much trouble getting on top of the turbos even at altitude.

 

[MarkBroviak]

I don't think a 4202 has enough turbine unless you gate around it a lot. I think a 4709 would work better for your power level. With a pusher vehicle, spooling on the line isn't as much of an issue as it is in drag racing or sled pulling. Most people have trouble building RPM under load to get the turbos lit, with a vehicle helping you get there, as long as you use your RPM, you shouldn't have much trouble getting on top of the turbos even at altitude.

Your correct but his issue that he is worried about is staying on it while pedaling it from traction which is a big issue for what he is doing. Situation like that a blowoff valve might serve him well to keep the shaft speed up while pedaling. In the end RPM's will be is friend and enemy at the same time! I have nothing but respect for him doing something like this because it is not easy to keep everything happy at that kind of power for that long!!!:thumb:

 

[nskyline34]

I don't think a 4202 has enough turbine unless you gate around it a lot. I think a 4709 would work better for your power level. With a pusher vehicle, spooling on the line isn't as much of an issue as it is in drag racing or sled pulling. Most people have trouble building RPM under load to get the turbos lit, with a vehicle helping you get there, as long as you use your RPM, you shouldn't have much trouble getting on top of the turbos even at altitude.

I’ve got a gate so hopefully the secondary turbo doesn’t become a giant restriction – however if it does I can always change out turbine housings right? I've got a friend who had a 75mm as his secondary and it was pretty laggy - it was a wild ride once it lit, but it definitely took a little bit. I know the GTX would be a little better than his BW - but I cant imagine it spooling 1,000 rpm sooner lol

Your correct but his issue that he is worried about is staying on it while pedaling it from traction which is a big issue for what he is doing. Situation like that a blowoff valve might serve him well to keep the shaft speed up while pedaling. In the end RPM's will be is friend and enemy at the same time! I have nothing but respect for him doing something like this because it is not easy to keep everything happy at that kind of power for that long!!!:thumb:

Explain more about your idea on the blow off valve - I've never thought of this before but it could be wise...?

Thank you for the great encouragement and sometimes I feel like I'm a little nuts for trying to make this happen - especially because technically there's no radiator in the car...just a whooooole lot of water to go through and keep it cool. (streamliner so there's no frontal area for a rad). It definitely will be a little challenging to make it all work, but at this point the wiring and computer have me the most stressed out - Bonneville Speed Week is in Aug and that's coming up REAL fast...

 

[Average_Ass_Lb7]

Compound Garrett Kit

I ran a compound kit that easily made 1500hp and spooled like a dream on the track and the street. That was fuel only 400% on a 1250us tune

It was a Garrett GTX4508r (80/87 t4 1.15) in the valley with a GT5541r (106mm t6) atmo

Can send some videos of the turbo's in action if you want, just lmk