"No buck" turbo UPDATE

[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...

[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.



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]

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.

[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"). 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.

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.