From compounds to a big single...

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wilmesbm

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Apr 12, 2010
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Ok, I have been running a 64/71.5/14 over a s480/83x74/1.10 t6 for a couple years now and am in the process of switching over to a large single. Due to high drive pressures, the divider in my manifold cracked and the exhaust housing of the super b special cracked as well. Because of the financial aspect of building a bigger set of compounds the way I would like to build them, I decided to make the truck strictly a toy and go to a big single.

For reference, the truck is a ppumped 24 valve with a maxed out 12mm pump, 6x.018s, and nitrous. Manual valvebody trans with a new DPC 4 disk converter with a 3000 rpm stall on the way. As stated above, the truck is just a toy, so I'm not really concerned with street manners at all. I'm not saying it will never see the street, but over the last 2 years I've only put a couple hundred miles on it. I mostly just race it these days, both on the dirt and the asphalt, but I wouldn't be opposed to hooking it to the sled from time to time as well.

So here's the question, what single would you guys recommend. Due to the cost, I'm probably going to stay with a s400 based charger. I'd like to be somewhere around 1000hp, maybe a little north of that with some spray. That's just a number I'm throwing out there though, I'm much more concerned with how it runs.

Also, for what it's worth, I tried running the 480/83x74/1.10 from my compound setup since I already had it and it has some violent compressor surge at 25-30 psi. No matter what, I can't get past it. From what I've read, that's due to the 83 wheel, but if changing housings will fix that problem, I'd be willing to go that route as well. If not, I'll just use that turbo in a compound setup on my common rail.

Thanks in advance for any insight you guys may be able to offer.
 
Where's your timing at? You sure the turbo you have won't work as a single with the new high stall converter? Where do you shift?
 
JQmile said:
Where's your timing at? You sure the turbo you have won't work as a single with the new high stall converter? Where do you shift?
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Timing is at 26 degrees. And no, I'm not sure that the turbo I currently have will not work once the new converter goes in, but I would be willing to try it if you think it may. As far as the shifting goes, I've only had the 480 on for day or so and have tried everything possible to get it to fully light and get passed the surge, but haven't had any luck thus far.
 
Fwiw I used to run a s478-83/74 turbine t4 .9 and it had to be run with an external wastegate or else it would surge violently before reaching peak boost like you explain.

I got up to right under 700 with the 87 turbine on the dyno, 1105 with a healthy amount of nitrous.

Any bigger on turbine you can forget about impressive dyno numbers on fuel only but it will put more power down on the track.
 
wilmesbm said:
Timing is at 26 degrees. And no, I'm not sure that the turbo I currently have will not work once the new converter goes in, but I would be willing to try it if you think it may. As far as the shifting goes, I've only had the 480 on for day or so and have tried everything possible to get it to fully light and get passed the surge, but haven't had any luck thus far.
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Are you rolling into the throttle or flooring it? What rpm? My 71mm A5k would surge bad until I bumped the timing, and then floored it rather than rolled into it. The timing bump plus the flooding of fuel actually stalled its spooling until later in the rpm range, then I could drive around the surge.

On your turbo you'll probably have to floor it at about 2500rpm and shift at about 4K to avoid surge I would think.
 
I am running a 68/83/.90 t4 and my 12valve has similar setup except 22 degress of timing
 
DieselheaD said:
Fwiw I used to run a s478-83/74 turbine t4 .9 and it had to be run with an external wastegate or else it would surge violently before reaching peak boost like you explain.

I got up to right under 700 with the 87 turbine on the dyno, 1105 with a healthy amount of nitrous.

Any bigger on turbine you can forget about impressive dyno numbers on fuel only but it will put more power down on the track.
Click to expand...

What did you waste gate it at to get around the surge? Mine will only surge in 5th gear and it's won't go over 25-30 lbs of boost then it will surge really bad. I took my boost port out of my compressor housing and it helped a lot, although it's probably not very efficient having a huge boost leak all the time. It also dropped my boost from 70# to 60#. Raising my timing didn't lower boost or reduce my surgery problem. I have 75/83/.90 as a single on a 12v with no intercooler and a 188/220 cam.
 
I wonder how an 80/87/1.0 would work on your setup. Should be good for right around 1000 whp
 
DieselheaD said:
Fwiw I used to run a s478-83/74 turbine t4 .9 and it had to be run with an external wastegate or else it would surge violently before reaching peak boost like you explain.

I got up to right under 700 with the 87 turbine on the dyno, 1105 with a healthy amount of nitrous.

Any bigger on turbine you can forget about impressive dyno numbers on fuel only but it will put more power down on the track.
Click to expand...

How did you gate around it? I have an external gate on the manifold right now and would be willing to play with that some if that would help.
 
JQmile said:
Are you rolling into the throttle or flooring it? What rpm? My 71mm A5k would surge bad until I bumped the timing, and then floored it rather than rolled into it. The timing bump plus the flooding of fuel actually stalled its spooling until later in the rpm range, then I could drive around the surge.

On your turbo you'll probably have to floor it at about 2500rpm and shift at about 4K to avoid surge I would think.
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That's rolling into it around 2500 rpm in both 2nd and 3rd gear. I'll try flooding it like you're saying tonight and see what kind of difference that makes.

How did yours run at the track when leaving the line already spooled? Did you still have the surge?
 
I ran an 80/87/1.0 single on my dmax and had zero issues with surge. It was a billet 7 blade wheel.
 
wilmesbm said:
How did you gate around it? I have an external gate on the manifold right now and would be willing to play with that some if that would help.
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I had a 50mm gate that would limit peak boost to around 60. I don't know when it started opening but I'm guessing it was early.

In the long run that setup will burn out and fail quick. The 87 turbine is the best all around, and you can get by without a gate. The dyno numbers I did were with a cast 6 blade 78, older 87 turbine, t4 1.0, and a 50mm gate around 60 lbs as well.
 
mike diesel said:
I ran an 80/87/1.0 single on my dmax and had zero issues with surge. It was a billet 7 blade wheel.
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apples to oranges.


op, had a similar issue with a 75/87 .90, p-pumped 24v 6x.013s with a 180 pump 5ks and 024s. was shifting at 4k+ but as soon as I would hit o/d, surged horrible. traded for a e.d. s472/83 and no more surging at wot.
 
That s480 with the 83 wheel isnt your best option. I had the same experience with one on a buddys truck. HTT actually recommended that to him:badidea:

Why are you getting away from the compounds? Swapping the s480 for one with a bigger turbine/housing would net a lot more power and lower drive pressure.

And for the record drive pressure didnt crack your manifold/turbine housing, heat did.
 
mathews8pt said:
That s480 with the 83 wheel isnt your best option. I had the same experience with one on a buddys truck. HTT actually recommended that to him:badidea:

Why are you getting away from the compounds? Swapping the s480 for one with a bigger turbine/housing would net a lot more power and lower drive pressure.

And for the record drive pressure didnt crack your manifold/turbine housing, heat did.
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I agree heat was the culprit, but attributed that to excessive drive pressures.

I tossed around the idea of building another set of compounds but just couldn't justify spending what it was going to cost me. I needed a new manifold and converter no matter what, just didn't want to add 2 new turbos to that as well. I loved that setup though, it made for a rowdy street setup. I'll probably end up doing something similar to my common rail for a rowdy driver.
 
The biggest single I personally have had good luck on my 12v using that 83 turbine is a 71mm inducer comp wheel.
 
After doing some research today, I think I'm going to try a 80/87 with either a 1.0 or 1.10 t4 housing. Does anyone have any experience with that particular turbo? Also, who has the best pricing on turbos right now? From what I have found, Forced Inductions is the cheapest at $1400.
 
wilmesbm said:
That's rolling into it around 2500 rpm in both 2nd and 3rd gear. I'll try flooding it like you're saying tonight and see what kind of difference that makes.

How did yours run at the track when leaving the line already spooled? Did you still have the surge?
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If I let the transmission do its thing (shifting at about 3200rpm) it worked until Overdrive, and then it would surge and fall off the charger completely. I put in an override switch and shifted at 4K and then it worked fine because the rpm drop still put the turbo high enough in the rpm band that it wouldn't surge.

Did you try flooring it at 2500 and see what happened? If you're rolling into it, the turbo will be gaining boost, but the engine won't be gaining much rpm, so its airflow intake will be about the same. If ya floor it, the engine will rapidly gain rpm and airflow, which "should" keep you out of surge. Part throttle drivability will still suck.
 
Not enough turbine wheel making it surge. Been in the exact same boat with same charger but it was ran as a single. But I had to jump to a 92 on that turbo. Try the 87 and a bigger Turbine housing
 
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