Twin turbo LQ1....

[NoMad]

So I have been planning around a single GT3076R turbo for my build but now have the possibility of two TD04 turbos off of an LF3/4 and just can't seem to find a set of maps for these turbos to see how they look with my expected flow numbers.

I have a decent idea for the plumbing but wanted to see what insight you all might have in the feasibility of using those turbos for the lightly built LQ1.

[Shaun41178(2)]

They will work just fine on an lq1. The lfx is 3.6l if I am not mistaken.

Maps would be nice but on 7 lbs you should.make about 300ish hp

[ericjon262]

I think a larger single would be way easier to install, but if you're up to the challenge, post pictures, we'd love to see them!

[draven]

These are the OEM twin TD04's in question from my LF3 XTS vSport. They definitely would get the LQ1 moving in the mid to lower mid range of the rpm band.. These are the XTS LF3 TD04s... not the LF3 CTSV and LF4 ATSV TD04s and are sized to get the 4340lb XTS tank moving.

From as best I can tell they are both identical with the only difference being the compressor inlet pipe where one is oval'd and slimmed down to clear the alternator.

[NoMad]

I thought I read they spun in opposite directions to facilitate piping efficiently.

As for fitment, I have some ideas in mind....

[draven]

For the CTSV and ATSV yes, XTSV no, probably due to it being a transverse setup.

[NoMad]

Good to know, I will adjust my design then.....

[Shaun41178(2)]

What are your power goals?

[NoMad]

400-500 at the wheels.

[The Dark Side of Will]

Looks like, with the integral wastegates and OE-specific packaging of everything, those turbos might be a little bulky. You might be able to build a system more easily using more generic turbos.

Are the turbine housings really attached to the main bodies with V-bands?
Example: with the wastegate and turbine housings integral, you don't get to clock the wastegate housing with respect to the turbine inlet... you're stuck with what worked for GM on a different engine in a different body.

[Shaun41178(2)]

A single gtx3576 will get the power goal you want and it's easier to package.

[NoMad]

Super aware of the 3076r and such. Just looking to possibly use what is on hand as a challenge.

[Shaun41178(2)]

If you have never built a turbo system in a fiero before stay single. Twins on a dohc will probably require custom manifolds

If you can weld and fabricate then a twin wont be difficult. But of course your budget will be almost double.

[The Dark Side of Will]

I've also thought it would be super fun to build a sequential twin system.

Build a crossover pipe connecting two log manifolds. Connect one turbo directly to the crossover pipe. Connect both the largest wastegate you can find AND a wastegate correctly sized for your total turbo capacity to the crossover pipe. Connect the outflow of the large wastegate to the turbine inlet of the second turbo. Setting up an engine management to control it might be fun... Better talk to Engine Labs about that algorithm.

When you roll into the throttle at low RPM, both wastegates will be closed and the turbo connected directly to the crossover pipe will spool and provide boost. Once either the first turbo hits the boost set point or engine RPM exceeds a set value, the big wastegate will open, spooling the second turbo. Once both turbos are spooled, the second wastegate will open, regulating boost to the set point.

Use BB center sections and even go VNT if you're adventurous and you'll have an insta-spooling turbo system.

[ericjon262]

If you have never built a turbo system in a fiero before stay single. Twins on a dohc will probably require custom manifolds

If you can weld and fabricate then a twin wont be difficult. But of course your budget will be almost double.

I would add that twins will still be at least double the work as well. I'm very glad I went single with mine...

[NoMad]

Fabrication isn't an issue. It is my favorite part.

That said, I just scored a used GTX3076R that just needs seals for $300! No shaft play and perfect shape impeller and exducer wheels and no physical damage to be found. Parts for rebuild set me back $50 and even if I just replace both outer halves to better match my needs I am still in around the $1000 mark rather than $2800 for the same direct from Garret.

[Shaun41178(2)]

Need this.

http://www.himni-racing.com/turbocharge ... 076r-gt30r

[ericjon262]

Fabrication isn't an issue. It is my favorite part.

That said, I just scored a used GTX3076R that just needs seals for $300! No shaft play and perfect shape impeller and exducer wheels and no physical damage to be found. Parts for rebuild set me back $50 and even if I just replace both outer halves to better match my needs I am still in around the $1000 mark rather than $2800 for the same direct from Garret.

I wasn't trying to imply that the work wasn't rewarding, more that the gain per work is higher with a single than twins. I look forward to see what you end up doing!