"No buck" turbo UPDATE

[exwestracer]

I had posted in the turbo "say hi" thread, but figured I'd start another thread for the budget readers. The idea was to see how cheaply a turbo setup could be installed and how much power could be expected without breaking anything. All the work was done by students at the Blairsville, PA Wyotech campus. The results were pretty amazing... An article is due out in the Jan 2011 "Auto Enthusiast", but here's a quick summary.

What we are working with here is a 350 Chevy 4 bolt with cast crank, powder rods, 9:1 cast pistons (may be hypers), and Edelbrock e-tec 170 heads. Cam was a .501 / [email protected] 110 LSA hydraulic flat tappet. Basically Edelbrock's 360hp crate combo. The engine has Edelbrock Pro-Flo (Magneti Marelli) port injection with a 4bbl TB. The ECU was swapped for a FAST XFI stand alone, as the Edelbrock unit is not compatible with boosted engines.

N/A engine dyno baseline was 375hp / 360lb ft. We scrounged a Holset HX35 turbo that came off a Dodge Cummins pickup. The turbo was plumbed to a set of block hugger headers with a custom Y pipe. A Tial 38mm external wastegate was used, as the stock internal gate controller could not be adjusted to safe boost levels for a gas engine. The turbo was set up to blow through the TB with a Turbonetics carb hat. The 27lb/hr injectors were swapped for a set of 43s.

We decided to limit boost to 15psi, and crossed our fingers... :). All pulls were made from 2500-6500 rpm.

After some tuning we ripped off a pull at 487hp /487lb ft. on 93 octane Citgo. Intake temps were getting out of hand, so we plumbed in a stock Dodge Cummins intercooler. That change (and some more fuel) netted a best pull of 527hp / 605lb ft. The best part: the turbo acted more like a supercharger, crossing into boost at 2000 rpm(!) and making 15psi throughout the pull range. The engine made over 500lb ft. all the way from 2500 to 6500 rpm.

The other best part: With some careful shopping, the turbo setup (less ECU) can be duplicated for just over $900 including all exhaust components AND an intercooler!

That's 150hp and 250lb ft. of useable power for less than a grand. Pretty good value I think!

[exwestracer]

So on to the update...:candle:

Since we found another Holset HX35 laying in the parts room, we decided to see just what this stock bottom end will survive...we are going TWINS this time around, with dual 4bbl TBs on a tunnel ram (again it was laying around from a past project...). We also swapped the cam for something a little more turbo friendly. We installed a Comp grind with [email protected] and a 114 LSA. Lift dropped into the .460 range, so we are putting a set of 1.6 Comp rockers on to get back to just under .500. We will actually be putting the single turbo setup back on first to see how the 2 camshafts compare power-wise.

I'll keep you posted...

[Wicked]

I love seeing this kinda stuff. Junkyard setups that is.

[PhillipM]

Yeah me too. I think it is becuase I would never do something like this... But secretely wish I would. Kinda like riding that scooter when your buddies aren't around! Haha

[DartorDemon]

Thats so cool. I really want to do something like this.

[exwestracer]

Well, we just did the pressure map for the HX35 on squirrelpf.com. Turns out it is a tad small for our application...but 2 of them are perfect...:twothumbs

https://static1.pt-content.com/images/noimg.gif

[shmoov69]

Wow, I thought that two would be pretty big and have quite a bit of lag.
Good luck! Tell us what goes first! LOL!

[Z06killinSBF]

Nice, and I have a Garret GTP-38 from a Powerstroke just hanging out at my house...........

[exwestracer]

Wow, I thought that two would be pretty big and have quite a bit of lag.
Good luck! Tell us what goes first! LOL!

Us, too. It was truly amazing how quick it spooled... I think 2 might just be a little "laggier"...

[WS6]

Oh man this sounds fantastic! I really want a very quick spooling turbo setup for my LT1. This sounds like it may be a path I could venture on to. Please keep us updated as I'd love to follow this closely. Just to verify, these are engine dyno numbers correct?

[WS6]

Oh and is there any chance we can get some dyno graphs at some point?

[John Wright]

The other best part: With some careful shopping, the turbo setup (less ECU) can be duplicated for just over $900 including all exhaust components AND an intercooler!

That's 150hp and 250lb ft. of useable power for less than a grand. Pretty good value I think!
That is cool.....so any of these diesel truck turbos will work?

[exwestracer]

That is cool.....so any of these diesel truck turbos will work?

Uhhh...I didn't say THAT...lol.

https://static1.pt-content.com/images/pt/2010/10/2ekoqqu-1.jpg

We figured the airflow requirements for the 350 were in line with the 5.9 Cummins at lower rpm, which turned out to be exactly the case (plus we had a couple Holsets laying around). The turbo ran out of legs a little early just because the diesel never needs that much air. Garrett's website has some excellent articles on turbo sizing.

http://www.turbobygarrett.com/turbobygarrett/tech_center/turbo_tech101.html

I'd think a single from a larger pickup engine would do a little better on top end.

WS6: Yes, those are flywheel HP numbers. I believe it would be an excellent choice if you are not looking for huge top end power. Obviously much more top end power can be made with a single turbo than what we achieved, with the usual tradeoff of bottom end torque and spool time. Stay tuned, we should be back on the dyno soon with the new cam combo and possibly a more realistic intercooler setup. I do have the dyno power graphs, but I'm not sure they can be converted into a format I can post. I'll check into that tonight if I get a chance.

[WS6]

Thanks Ray. I'm looking for broad torque that comes on early. Basically, if I could come up with a positive displacement turbo system I'd be so happy. I'm not a fan of waiting for a turbo to spool which is why I don't like pro-chargers either. Yeah, top end power is amazing but a pro-charger and the typical turbo build style is not what I'm after. I know I might end up making some compromises but I'm still confident I could build a turbo system that would meet my needs without getting crazy. After all, 500hp/500+ ftlbs isn't too hard and that's basically my goal.

[exwestracer]

I know I might end up making some compromises but I'm still confident I could build a turbo system that would meet my needs without getting crazy. After all, 500hp/500+ ftlbs isn't too hard and that's basically my goal.

I can guarantee you that much is possible... :yeah:

[exwestracer]

Basically, if I could come up with a positive displacement turbo system I'd be so happy. I'm not a fan of waiting for a turbo to spool which is why I don't like pro-chargers either.

A picture I saw last night got me thinking, and I did some rambling over on the turbo forum this morning. Doesn't pertain to this thread, but you might find it interesting...

www.theturboforums.com/smf/index.php?topic=144162.0

[WS6]

I've thought about compounding a pair of turbos in order to really stretch the power band out. Diesel trucks are starting to do this with amazing results. The new F350s are compound turbos. It's going to stay on my mind but I believe it'll be too much overall for my simple street car. Thanks Ray

Trey

[shmoov69]

Definately NOT simple! Compounding is tricky from what I hear.

[exwestracer]

Looking back on it, I titled that other thread incorrectly. My idea there was to use a small supercharger to get some torque output and some exhaust energy, and then cut it out of the system and use only turbo boost for higher HP. I may even attempt this on the "no-buck" engine if the twins take some spool time. We should be able to find a couple small Eatons and adapt them to a Vortec truck type manifold lower half.

Hehe, from one cast-off turbo to twin turbos and twin Eatons....that would be fun! :hmm:...:drool:

[WS6]

Hellion racing, I think that's right, has a twin turbo setup for the new Shelby cobras that keeps the factory Eaton blower on the engine. So basically, they have enacted your idea already.

[Z06killinSBF]

The idea has been used alot in the past. Eaton guys use the turbos all the time and there are some Ford GTs with stock blowers and twin turbos making excess of 1000hp.

[exwestracer]

The idea has been used alot in the past. Eaton guys use the turbos all the time and there are some Ford GTs with stock blowers and twin turbos making excess of 1000hp.

Yeah, I see that after some more digging around.

Well, it's back on the dyno N/A. Going to try to get the new cam run in on Sunday. No pulls, just break-in time. Then we're putting the single back on and we'll see if the "turbo-friendly" cam makes any difference.

Just found out we have the pieces for an all-forged 327. That may be our "permanent" twin turbo engine... The mounts are almost done to fit the SBC in the Magnum wagon, and we're getting the shifter and clutch figured out for the 6 speed.

[WS6]

Are you expecting the diesel turbo to work better with the slightly smaller engine?

[exwestracer]

Are you expecting the diesel turbo to work better with the slightly smaller engine?

Not really. The air mass requirement for the 327 should actually be higher as we plan on turning more rpm with it. We now know that the single turbo was off the airflow map past about 4000rpm. We limited the tests to 6500 to save the engine, and because there was really nothing to be gained by spinning it faster. The 327 with twin turbos should make power past 7000, with an expected increase in lag and loss of low rpm torque.

[WS6]

ok that's what I was thinking yáll would do with the 327, spin it higher. I just wasn't sure since I know you don't have to spin them higher. Though, if it was my engine, I would spin it higher as well.

[exwestracer]

ok that's what I was thinking yáll would do with the 327, spin it higher. I just wasn't sure since I know you don't have to spin them higher. Though, if it was my engine, I would spin it higher as well.

We are moving away from the bolt on and go idea to a true turbo designed engine package. There is no advantage to going to the 327, other than we had it. As long as we are going to the shorter stroke/higher rpm potential, we are going to tailor the twin turbo setup to it. The twins should give us good air mass at relatively low compressor speed, so we're hoping that will offset some of the lag from splitting the exhaust energy in half..

[overZealous1]

you wouldn't happen to be the mr. kaufman who used to teach shop class at tigard high school about 20 years ago would ya? iirc, brother to the kaufman products guy?

[exwestracer]

you wouldn't happen to be the mr. kaufman who used to teach shop class at tigard high school about 20 years ago would ya? iirc, brother to the kaufman products guy?

Haha....Nooo, but I am the Mr. Kaufman who taught auto shop at Mt. Whitney high school about 10 years ago...:twothumbs

[overZealous1]

after further research, seems there is 2 n's in kaufmann for them. and kaufmann products went away years ago, lol. oh well, would have been fun to talk with him again. i guess you'll do, hahhaa.

all joking aside, cool projects you guys are working on. about to start my twin gt35 build on a bone stock 2008 5.3 ls. may swap out head gaskets only to get comp closer to 9/1, but that is it for now. once total car is done, build up a final engine and turn boost up. but, all fab work will already be done. shooting for 500rwhp on stock engine. should hit it and be reliable.

[exwestracer]

Well, the new cam is run in on the 350, the single turbo is back on, and we are looking at a more feasible intercooler setup for the next round of tests. (no data yet)

"In other news"...the Weiand Stealth Ram intake showed up, so we are setting to work on making 2 adapter plates for the "semi-ITB" setup. The "box" top half will stay on the shelf.

https://static1.pt-content.com/images/pt/2010/11/9257540-1.jpg

We will have just enough plenum area to allow the twin 4bbl TBs to each feed 4 cylinders. I'm hoping the throttle response will be more like an ITB turbo setup (not having to re-pressurize a large plenum volume when the throttle is opened). I'm also hoping this will improve N/A throttle response, and therefore spool time. We'll see...

The mounts are complete to install the SBC and 6 speed in the Magnum wagon, just need to figure out the hydraulic clutch setup (converting from pull to push) and build some headers.

[exwestracer]

42077
Just a quick look at where we're going with the intake. This isn't the Stealth Ram, it's an old tunnel bottom we used for mock-up.

No dyno results yet. The dyno has been tied up with a blown SBC.

[WS6]

Cool. Keep us posted. Thanks

[exwestracer]

No dyno results this week. The RTV'd on oil pan decided to start drooling on the floor. Fuggit, I'm goin home. :Alchy:

[James21]

I'm building the same set up for my Nova right now, I have the 5.9 banks turbo. Its awesome to see the amount of power you guys are putting down, Its great motivation

[exwestracer]

STILL waiting for the blower motor to come off the dyno...maybe tomorrow.

Adaptor plates for the twin 4bbl setup are almost finished. For now, we are flipping a set of stock rear dump exhaust manifolds to feed the twins.

Clutch work on the Magnum is stalled unitl sombody above my pay grade figures out what we can afford for a clutch...

[ledslinger]

awesome thread!

[exwestracer]

Well, we finally got back on the dyno tonight (the blower motor "blew"):drive2:. The ambient temp in the dyno cell was about 40F, so we didn't bother with the fan for the intercooler.

The "other" Holset spooled even faster than the first one. Don't know why, they should be identical turbos. Maybe it's the "torque" cam we installed... Anyway, we had a persistent misfire that none of us instructors really had time to troubleshoot (busy night...). I'm pretty sure it's a bad set of wires (they've been through hell). We clubbed it hard once anyway, aborted the run at 5000 rpm and made 458 hp/ 618 lb ft of torque...on 7 cylinders.:twothumbs

This could be interesting...

[MonzaRacer]

Hey Ray, I am looking at doing a twin turbo, long rod 302 Chevy with double humps and a modded LT1 intake and I am having problem figuring out how to input my info in the squirrelpf web sight. IF I am doing it right I was told a T04E 46 trim was idea for twins IF I am reading things right.
And I have acquired a 454 bone stock for my Caprice for now ,then I am going to rebuild my 402bbc for lower compression and dual HX35 turbos, but I am still wondering if I am doing the information input right.
Heck who knows I may pull the roller 355 out of my 78 C10 and slide the twin turbo 402 into it instead,,,,.
Heck I am just trying to get into setting up turbos and so far the squirrel sight looks good, but I am kind of lost on if I am doing it right.
Is rthere any good place to get more info on turbo setup and such. I am trying to see if the cheaper turbos off ebay come close enough to get the 302 running then upgrade to better name brand later.
Lee

[H2Ogbodies]

I'm interested in how your swap works too Ray. I'm working with a local turbo shop that building me a custom pair of Holset turbos-they work alongside engineers for Borg Warner on tech sheets based on engine specs. I've decided to build this 377 and run dual 44mm-ish turbos and run as high as 8000 RPM's. The biggest issue is having low RPM torque and I've been assured with intercooled twins I should have virtually no lag in spooling from 1800 RPM-on. If the BW guys are correct, this will be fun! I'm ordering the 304 misc. elbows/bends to start fabbing headers for it at the moment.

[WS6]

Sounds promising Ray.

And H2O, keep us updated on your build too. I'd love to build a turbo system that spools quick so I can build broad torque.

[exwestracer]

Well, results are inconclusive... We had one pull that showed 505hp / 670lb ft (no that's NOT a typo) at 5000 rpm. Then we couldn't back it up. Blew a charge pipe off, then this, then that...then we gave up. 3 pulls around 450hp / 510lb ft and we called it quits.

Under load, the turbo went into boost as soon as we cracked the throttle...

Boost (and hp) were falling off past 5000 rpm. We wre simply running out of air, so I'm wondering if these 2 turbos are really the same after all. https://static1.pt-content.com/images/noimg.gif Time to do some measuring...as there are no markings on either turbo. Won't help much on a twin setup if the turbos are different.

Going to concentrate on getting the twin setup together and getting the 327 built. Guess we're done for awhile.

[exwestracer]

OK, so it wasn't much of a mystery...
https://static1.pt-content.com/images/pt/2010/11/15rxdtg-1.jpg

The turbo we used in the first tests (right) was a 60mm, this one was about a 54. No, I never sat them side by side, never had time or a reason to...:dunno:

There are no more of the larger size around, so I'm going to swap the big one to the diesel guys for a matching small one. Probably take some time to get it all together. I'll keep you posted if there are any interesting developments...

[shmoov69]

Is this chassis dyno or engine dyno power?

[MonzaRacer]

Hey Jimmy, he is using the schools dyno I believe. No car involved.

[shmoov69]

That's what I figured, good power!!

[Wesley J]

I think you need to look at it as an whole system, not just the components. You're putting a dramatic amount more air mass at higher velocity and density through the motor. All those things add up to a non linear increase in friction, resulting in decreased gains at higher RPMs. If you boost limit the turbos with a waste gate then your effective boost goes down as RPM goes up. PSI at the waste gate - pressure drop through the motor = cylinder boost. Say at 3000 rpm you have 1 psi pressure drop through the motor (from turbo to spark plug) and then at 6000 rpm you have 2.5 psi pressure drop though the motor. You're effectively droping the in cyclinder boost by 1.5 psi.

This is why the new motors do so well under boost. The heads flow so well but they're under cammed in an NA setup. Add pressure and because they provide such an efficient flowpath, they make huge power numbers and can live with higher boost and CR.

[exwestracer]

Article on the original turbo setup is out in the Jan 2011 issue of Auto Enthusiast. Titled "Learning Curve". I don't know who Kevin Harper is, but he did a good job of rearranging a few words in the story I wrote...:secret:

[Nessumsar]

Any news Ray?

[exwestracer]

Any news Ray?

Naah...politlcal infighting stalled it. Another dept. didn't like the fact that we got some ink with "their" borrowed turbos, I guess. I've kept rolling on the little stuff that I can control.

I'm back to teaching Chassis Fabrication come January, so I may get the Magnum down there to finish up the drivetrain and get the turbo headers built. We never could find any stock manifolds that would mount the turbos where they needed to be... The 327 is waiting on the piston/rod assemblies to get back from the machine shop. Maybe next class the High Perf guys will get it put together. The Stealth Ram and Edelbrock E-Tec heads have been match ported, and the adaptor plates for the dual 4bbl TBs are done.

I'll try to get a couple pics up if I get it all bolted together, but this one's gonna go quiet for awhile...

[exwestracer]

Just found this: http://editions.amospublishing.com/KRPR/default.aspx?d=20110101
It's the online version of the magazine. If you click on the cover it opens. Article starts on page 30.