Not really junkyard, but project "no buck" turbo...

Not exactly a 2000hp monster, but this might be of some interest to 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 (don't hate... ) 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!

#ad


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.

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...

http://www.squirrelpf.com/turbocalc/...oduct_ id=113

 

Re: Not really junkyard, but project "no buck" turbo...

How hot did the intake charge get?

 

Re: Not really junkyard, but project "no buck" turbo...

No charge temp gauge, but we misted some water on the charge pipe right after a pull, and it was steaming off...so pretty hot!

Judging by the difference the intercooler made, I'd say we had a hair dryer at high rpm... That's one reason we trying the twins: to see if we can get the same airflow at less boost and charge temp. We'll see.

 

Re: Not really junkyard, but project "no buck" turbo...

is that a wrx blow of valve ?



this is awesome !! holsets are awesome turbos i love them. cant wait to see what the twins put out. when you going to be dynoing them ?

 

Re: Not really junkyard, but project "no buck" turbo...

Good eye on the BOV! Yes, it was another part that was "just lying around"... This time, I think we'll be doing some ebay shopping, as we'll need 2 of everything. If the twins lower the charge temp enough, I'll ditch the intercooler all together. Goal is to get the engine sorted, then it is going into a Dodge Magnum wagon (hey, the stock V6 blew up... :noidea with a ZF 6 speed.

The plan is to run the new cam in N/A next week, then put the single Holset back on for a A to B cam test. After that, I'll revamp the exhaust for the twins and swap on the tunnel ram base and twin 4bbls. That will probably take about a month with the way things go here... We're looking for a lot of airflow, as I'm trying to keep boost pressure down as much as possible. HP goal is 600+ non-intercooled (with CAST crank and pistons!), and I don't think we're that far off. If it breaks, we'll have to build a "real" long block, and really tighten the screw on it.

 

Re: Not really junkyard, but project "no buck" turbo...

well i cant wait man. really excited to see how it turns out

 

Re: Not really junkyard, but project "no buck" turbo...

That is nice you have the use of the engine dyno and all these parts "laying around". Cool test, You usually don't see budget combos set up on the dyno like that...oh the possible combos ^-^

 

Re: Not really junkyard, but project "no buck" turbo...

Yeah, the diesel guys next door change a lot of stuff out and are very helpful. I'd thank them, but then they'd find out...... hmy:

 

Re: Not really junkyard, but project "no buck" turbo...

it will be interesting to see how well you can tune the twin 4bbl, considering that there are some big numbers being made from 750's on engines up into the 400cube reigon...

 

Re: Not really junkyard, but project "no buck" turbo...

That same thought had crossed my mind. This is a true research (for us) project. I know it's all been done before, but we're slowly developing this from a N/A engine with a turbo slapped on into a true turbo-based system. The idea behind the twin 4bbl is to reduce the amount of boost pressure needed for airflow. They will be set up as ITBs on the bottom half of a tunnel ram, with a big charge pipe balance tube connecting the hats above the throttles. I know we will be giving up some low end torque (and spool), but I'm thinking the low plenum volume will help with the initial hit. I don't think a tune is our biggest issue at this point. Someone mentioned the word "budget" last week and, if I've learned from history, that is the corporate signal for STOP.

If the magazine article about the first tests is well received, we may get some more help with what we can't scrounge...

 

Re: Not really junkyard, but project "no buck" turbo...

Going back on the dyno tonight (N/A) to run the new cam in. Then the single goes back on for a little more abuse to see what difference the cam swap made. We went from a .501/[email protected] on 110 LSA to a .463/218@050 on 114. Installed a set of 1.6 rockers to get the lift back to .493. Tack welded the oil pump pickup on as it was laying in the bottom of the pan...you know, little stuff...

The flanges and exh elbows for the twins are done. The turbos will be located on either side of the square tube bracket in the photo above. Inlets are pointing forward, exh out to the rear. Looks like we will be using a modified LT1 "mailbox" intake and twin TBs for now.

Anybody got an EFI compatible tunnel ram for LT1/Vortec they want to loan/donate...? Getting the injector bosses and other mods done to the old style tunnel we have has suddenly become a "problem". :stroke:

 

Re: Not really junkyard, but project "no buck" turbo...

We are also finishing the motor mounts, clutch pedal, etc in the Magnum wagon...so the thing will have a home soon.

 

Re: Not really junkyard, but project "no buck" turbo...

you going to be posting up the dyno results tonight ?

 

Re: Not really junkyard, but project "no buck" turbo...

awesome, i love stuff like this, just doing it for no reason other than to see how it does and have fun, and learn something in the process, because if its an engine you dont care about, you will try anything lol

 

Re: Not really junkyard, but project "no buck" turbo...

No pulls, just break in...

 

Re: Not really junkyard, but project "no buck" turbo...

Awsome! I would like to have had that when I was in school!

 

Re: Not really junkyard, but project "no buck" turbo...

Well, it's back on the dyno. No run time tonight, as things got kind of "interrupted"...

We also found (I'm not kidding) everything to put together a full-forged 327 shortblock, so it looks like that will be our long-term engine that goes into the Dodge Magnum... ... with the twins and 6 speed.

 

Re: Not really junkyard, but project "no buck" turbo...

did you ever mount 2 of them on that engine?

 

Re: Not really junkyard, but project "no buck" turbo...

Still going to do that for dyno runs. The single will go back on first to get back to back cam swap data. We know now that the single turbo is too small past about 4000 rpm, so the twins should have a much higher power potential (just about perfect by the compressor map). I have no doubt we will end up breaking something in the 350 (I'll be shocked if we don't). The 327 should be set up to handle the HP potential much better over the long term.

 

Re: Not really junkyard, but project "no buck" turbo...

Got the cam run in last night. The other Holset turbo is going on as a single so we can see how it compares to the first one.

Wonder of wonders, the Weiand Stealth Ram intake also showed up, so we are going ahead with the plans for 2 4bbl TBs. We're going to build 2 adaptor plates to position the TBs on the bottom half of the tunnel ram. It occured to me last night (because I'm partially retarded...and have too many other projects I'm watching over ), that going true ITB won't work because the throttles are way too small in that case.
#ad



We're going to try a "semi-ITB" setup, with just enough spacer/plenum under the each of the TBs to allow them to feed all 4 cylinders.

The motor mounts are done, and we've got a plastic SBC bolted in the Magnum for real. Now I just need to figure out this stupid F%*ing clutch issue. Figures the school would pick up a ridiculously expensive trans that no one uses...