Holset Turbos, PART 6

[darkhorizon]

I have used a regular ole boost gauge to read backpressure in the past.

 

[dsm-onster]

Well it should come as no surprise. A well matched compressor and turbine should produce more boost than backpressure. . .

AMEN! Tell that to the goofs who say a diesel turbo isn't set up for a gasoline application. What's the garret upgrade to the ford powerstroke again?

I don't know how the pressure was measured . . . Vigge has extensive logging capability. I'd look into his thread. . . OR either just email him via his thread.

 

[SpeedAddict62]

I have used a regular ole boost gauge to read backpressure in the past.

How'd you hook it up? Pictures? I've seen an oil pressure gauge used as well.

 

[GST95]

Ive tested the backpressure on my PTE SCM6031e which was my previous setup. If you have a EGT gauge already its easy to do. I used about 3 feet of copper tubing and a 0-60 water pressure gauge (any pressure guage will work) and a couple of fittings. I just put the guage under my wiper and shut the hood. Make sure the tubing isnt on anything that will melt for the first few inches at the hot end. If i make another one, ill probably put something inline to dampen the pulses since the needle bounced around a lot.

I didnt want to put the EGT in my new setup, so i cant measure backpressure of the new setup. It does make me curious what mine is though and i might find a different way to tap into it.

FWIW, my SCM6031e at 30psi boost i was seeing 45+psi backpressure on my gauge at 7500rpm. My fittings had a few leaks so was probably closer to 47-50psi backpressure. Precision told me that 1-1.5:1 backpressure to boost ratio is normal with 1:1 being better for power and 1.5:1 being better for spoolup.

 

[dsm-onster]

That bolton PTE housing is absolute crap. They shoud have said that when they were ont he phone with you. "Our turbine housign will require more backpressure to spin the turbo." No better flowing than a 7cm^2 16g housing. And you had an old garrett t31 wheel (70s tech) that flows terrible for it's size. . . Yes that Is normal. For last century's turbos

Here's the PM from Vigge. He checks into this thread all time.

Somebody asked how back pressure was measured and it through this pipe
http://www1.garaget.org/archive/2/10...50-1557500.jpg (old #14 housing in picture)
and was connected to dyno pressure sensor during the dyno runs.
Manifold absolute pressure and back pressure (absolute pressure also) added to same plot with power and torque
http://www.stcf.net/ProjectX/run3_4.jpg
orignial boost curve against time from datalogger
http://www.stcf.net/ProjectX/run3_5.jpg
Dyno sweep time wise is faster than road 3rd gear sweep, so lower rpm tq suffers.

 

[GST95]

That bolton PTE housing is absolute crap. They shoud have said that when they were ont he phone with you. "Our turbine housign will require more backpressure to spin the turbo." No better flowing than a 7cm^2 16g housing. And you had an old garrett t31 wheel (70s tech) that flows terrible for it's size. . . Yes that Is normal. For last century's turbos

Thats why its now a paperweight. I spent a lot of time trying to work around that turbo thinking it wasnt my bottleneck. I probably would have been better off with an e3 16g to be honest. I eventually found something better.

BTW, your first link in the quote doesnt work. Its probably the 10...50 part which probably has something missing.

 

[red_devil]

I would like to see someone test a Holset with the bep bolt on housing. Im debating on going with a 2.0 but revving to 8300rpm or with a 2.3 stroker revving to 7500rpm. Would that high of rev be a waste if im using the bolt-on housing you think?

 

[donniekak]

I would like to see someone test a Holset with the bep bolt on housing. Im debating on going with a 2.0 but revving to 8300rpm or with a 2.3 stroker revving to 7500rpm. Would that high of rev be a waste if im using the bolt-on housing you think?

I used the bolt on hx40 housing, and it seemed to flow better than any other mitsu flanged turbo i've ever experienced. It has been pushed over 650 whp. In my opinion strokers are a bad idea for these cars. We have a transmission that cannot stand torque. High revs and moderate torque make as much power as lower revs and more torque. Big cams, stock displacement, and a large turbo are the way to go, unless you love building transmissions.

 

[v8s_are_slow]

I would like to see someone test a Holset with the bep bolt on housing. Im debating on going with a 2.0 but revving to 8300rpm or with a 2.3 stroker revving to 7500rpm. Would that high of rev be a waste if im using the bolt-on housing you think?

Wouldn't be a waste if you're still making power at those rpms.

 

[red_devil]

Wouldn't be a waste if you're still making power at those rpms.

Well im thinking about going ported 2G head with 1mm oversized valves, Kelford 272s and dual springs. Just hoping the housing isnt choking itself.

 

[1gDSM4g63]

Well im thinking about going ported 2G head with 1mm oversized valves, Kelford 272s and dual springs. Just hoping the housing isnt choking itself.

What is your goal and I wouldn't recommend going that far on the head with a stock block.

 

[DSMsOwnYourV8]

Happy to be joining the holset community... Just picked up an Holset HX40 8 blade with a t3/BEP. I plan on getting an ERL cast manifold once the funds permit, and running low boost until I can get DSMlink and build the head.

 

[red_devil]

What is your goal and I wouldn't recommend going that far on the head with a stock block.

No im looking at 6 bolt Frankenstein with evo 9 pistons and Kiggy Gurdle, L19s and felpr MLS. Looking for 450-500awhp semi dd.

 

[dsm-onster]

Like any turbine housing or turbine wheel, the housing will only choke after a certain hp/flow level, not an rpm level. If you're still capable of making 680whp (badman21's record) at 8300rpms, then the turbo will do it.

The stroker at 7500rpms is displacing as much volume as a 2.0 at 9K. IF the bolton hx40 were to choke, the stroker at 7500rpms would choke it before the 8500rpm 2.0L motor would.

 

[1gDSM4g63]

No im looking at 6 bolt Frankenstein with evo 9 pistons and Kiggy Gurdle, L19s and felpr MLS. Looking for 450-500awhp semi dd.

You don't need to go as far a ported head with over sized valves for that.

 

[v8s_are_slow]

You'd be surprised at just how far these heads will go in stock form. Next build I have will have a built bottom end with a stock unported 2g head.

 

[red_devil]

You'd be surprised at just how far these heads will go in stock form. Next build I have will have a built bottom end with a stock unported 2g head.

But stick with the larger valves? Im hoping my evo3 IM will flow enough at that rpm. I will also be getting a fp exhaust manifold.

 

[1gDSM4g63]

Don't need to go with larger valves, porting is more important than over sized valves. You'll make your goals easily with new valve springs and cams. I made 470 whp without serious tuning when I had Manley springs and BC 280. You'll probably be better off going to a SMIM than over sized valve and I'd be more worry about the power that the internal wastegate can handle.

 

[red_devil]

Don't need to go with larger valves, porting is more important than over sized valves. You'll make your goals easily with new valve springs and cams. I made 470 whp without serious tuning when I had Manley springs and BC 280. You'll probably be better off going to a SMIM than over sized valve and I'd be more worry about the power that the internal wastegate can handle.

When I build my motor im going external with 50/50 meth, dsmlink, and 1250ccs +

 

[DraginX]

Has anyone tried a twin scroll setup with a 19cm2 housing hx40 yet? I've been watching for the guys that said they were going with this setup but haven't seen anything yet. I would love to see the reviews on it as I think it'll be a monster performer

 

[darkhorizon]

Update on my HE351VE turbo... latest project...

160k+ mile 3800 lowcompression supercharged block.
1.9 ratio roller rockers, otherwise stock motor.
Blocked off blower housing intake manifold.
620cc injectors
351ve mounted to stock exhaust manifold (stock manifold is tubular stainless). Custom front manifold.
ebay "double wide" w/a intercooler.
Ebay intercooler pipe kit.
LC1 wideband with ECU tuning software and special maf sensor setup (equiv to HPTuners)
T25 DSM actuator for the VGT actuation.
DSM crushed 1g bov.
Tial 38mm wastegate.

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Boost response is INSANE with the VGT. The car was supercharged before, and its fairly similar feeling with the VGT open to about 50% , then opening to full at 8PSI+.

Ran 12.4@115 without trying very hard the other day, on 9psi, flowing about 38lb/m worth of air. Tune was touched up significantly sense, and VGT was hooked up (was just wide open 21cm exhaust housing before).

Planning on 16psi soon, with the possibility of a bit more. I expect easy low 11's at 130, or high 10s.

vid of first run ever.. didnt get a vid of the "real" faster run.

YouTube - Turbo Fiero 1st run low boost

 

[Hubbard 0]

Haha, that's awesome Scott.

You're really going crazy with this car.

 

[darkhorizon]

I am pissed that it is going to be soooooooo much faster than my automatic turd bucket.

I hope I can still put down some better 1/4 times, but he will kill me in trap speed.

 

[kp116]

I would like to see someone test a Holset with the bep bolt on housing. Im debating on going with a 2.0 but revving to 8300rpm or with a 2.3 stroker revving to 7500rpm. Would that high of rev be a waste if im using the bolt-on housing you think?

I am on a hx40 with the bolt-on housing with a stock intake, stock 6 bolt head with BC 272's and springs and retainers. I am only reving it out to 7500rpm and flowing about 60lbs/min at 34psi. My cars weighs 3150 with me in it and my best trap was 134mph with beak up issues the top of fourth.. That weight and trap comes out to be around 600whp give or take... I am still on a stock intake and making that much power with a bolt-on turbo...

 

[dsm-onster]

^^^Yes. Guys look at the holset resutls thread. The stock head, stock 7.8 CR and 272s do excellent with these high trim turbos. Not that high compression and big head porting and what not work. But these wheels flow VERY well with smaller housings. Without getting into the fluid dynamic formulas and 2/3d drawings, the results thread show that the best thing about these turbos is thayt they seam to work very well with the common setup.

And the 4g6* head flows VERY well with a turbo that nets more efficiency at higher boost. These heads day in and day out show they need little work to produce big numbers. Now add a pair of wheels that are VERY efficient. All that's needed is to get the exhaust gases OUT OF THERE: a turbine that takes less energy to make the same work (efficient) give the bypass or wastegate more flow and a compressor that takes less energy to make the flow available lets the wastegate bypass more exhaust. Both results in more exhaust flow and nets more total flow. The bottleneck has never been the head. It has been the cams. Look at what other turbos need to net the same airflow numbers.

Great stuff darkhorizon. . . I really like the fiero platform. . . And I'll admit it on a dsm forum