Duramax Street Rod
- Thread starter Turbo Performance
- Start date
Thanks for all the compliments guys. Being my first build I literally had no idea how long it would take or how hard it would be. I'd like to be ready for Phoenix in March but I think I'm done setting deadlines just to blow past them. 
Some water injection may be all you need :thumb: when you say low boost- what are we talking about here?
This project is really cool man, glad to see the new progress!
This project is really cool man, glad to see the new progress!
Thanks for all the compliments guys. Being my first build I literally had no idea how long it would take or how hard it would be. I'd like to be ready for Phoenix in March but I think I'm done setting deadlines just to blow past them.
ooohhhh that would be cool to see!!
Thanks! Around 20psi should get the job done for just about anything I need. At least on paper. If I ever decide to test the short block, 30ish psi. It's only a ballpark since I'm having a bit of trouble finding maps to plug in for these Holsets.
Is that a pair of HE351's from an 04.5+ cummins?
I have experience with the HE341 (56mm new version of the HY). HE351 (60mm compressor, same 7 blade wheel as most Super HX40's, but the tiny exhaust turbine/housing) and some other Holset stuff (Super HX40, aftermarket housings etc.) from different setups my on Subaru over the years.. I may be able to help a bit....
I have experience with the HE341 (56mm new version of the HY). HE351 (60mm compressor, same 7 blade wheel as most Super HX40's, but the tiny exhaust turbine/housing) and some other Holset stuff (Super HX40, aftermarket housings etc.) from different setups my on Subaru over the years.. I may be able to help a bit....
Yeah, HE351's. Hoping the small exhaust housing will help them light quick. Plus they were basically free which warranted at least trying them out. Plan on welding the gates on the housings shut and running a pair of 44mm external gates to keep them in check.
It will be interesting to see how quick they spool in this setup. Your exhaust is short and to the point :thumb: And so is the intake plumbing for that matter lol
They are quite lopsided, I don't see how it's possible to max out the compressor without having insane drive pressure numbers... but in your case I don't think it matters since a pair of those should be good for 900+ whp :rofl: If they spool ok then you have done very well for the price. I like the 351, but I had a Super HX40 in a .70 a/r BEP single scroll housing (6mm larger turbine wheel and larger housing) that spooled almost identical and made quite a bit more power. This setup also cost me quite a bit more, Super HX40 and a new BEP housing was $500+
I can find a compressor map if you want it... but I don't think you will know what you have until you try it. Honestly this looks like it will be a really good setup. My experience with Holset turbo's has been very positive! They are tough bastards, there was a cummins guy pushing a 351 to 50+ psi for quite some time. Make sure you pull the silencer rings out though, that's like 100 more hp right there :roflmao:
They are quite lopsided, I don't see how it's possible to max out the compressor without having insane drive pressure numbers... but in your case I don't think it matters since a pair of those should be good for 900+ whp :rofl: If they spool ok then you have done very well for the price. I like the 351, but I had a Super HX40 in a .70 a/r BEP single scroll housing (6mm larger turbine wheel and larger housing) that spooled almost identical and made quite a bit more power. This setup also cost me quite a bit more, Super HX40 and a new BEP housing was $500+
I can find a compressor map if you want it... but I don't think you will know what you have until you try it. Honestly this looks like it will be a really good setup. My experience with Holset turbo's has been very positive! They are tough bastards, there was a cummins guy pushing a 351 to 50+ psi for quite some time. Make sure you pull the silencer rings out though, that's like 100 more hp right there :roflmao:
Thanks for the info. I figure if I can get them to make boost quick, I can bleed them off on the top end with gates. I know I can make more power with different chargers but with the entire truck build being sub 10K it's tough to justify the money when I can probably do it with these. I don't plan on needing a bunch of power (600hp tops) to have a very fun street/strip ride. With a stock short block, I don't think these turbo's will be the thing holding me back if I ever decide to turn up the power and fish for a deep number at the track.
I could be wrong, but I don't think the heads will flow enough at that boost to make much power without lots of smoke and high EGTs. That is unless you do some major head work with a really aggressive cam.
What makes you say that? Heads will be mildly ported, stock cam. I suppose worst case scenario, I have to go to a proven turbo setup.
Unless the air is much denser, it will not flow any more air at 20 PSI than the stock turbo will, no matter what turbo(s) you use, and without an intercooler (or some other way of cooling the air charge), you won't get the air to be more dense.
My wild guess would be 25psi, 36-3800rpms and some water injection.. but it's just that... a guess. Even though those 9cm housings and 351 turbine wheels are pretty small, with two of them, that motor should breathe pretty well. So it should move quite a bit of air for the boost. Either way this is different and creative and it will be interesting to see what kind of power it makes etc.
