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M35 Turbo Upgrade.


FIA510

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Not just the large puck wastegates, the stock actuator has bugger all travel and blows open with the slightest manifold pressure.

Yep, I can open it by hand. I can't even move the one on my Borg Warner turbo.

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Ok it's now almost 1300rpm better spool. The issue with the Hypergear Rev 4 was the waste gate. I have a high boost Borg Warner EFR actuator with adjustable rod installed now. The difference in stiffness is probably 400% or more. Adjusting it this way does bring up minimum boost levels. An even better way would be a dual port wastegate like a forge item, the same as what the Bathurst R32 GTR ran. This would enable the gate to be actively held closed without increasing minimum boost. I had 20psi at 4700rpm in 3rd previously, I now have 20.4psi at 3431rpm in 3rd...and I'm currently on my BP98 tune not E85

Matt

Edited by BoostdR
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The benefit is a stronger spring holding the big puck closed before target boost is reached. Simple as that. It's like Scott's spring mod on steroids. The borgwarner can/spring is so stiff I can't move it by hand at all. Even very very hard with pliers. I can fully open the OEM can arm by hand without too much trouble.

Edited by BoostdR
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Yea I get how the wastegate etc works. Was more asking if there is something different about the BW actuator OTHER THAN THE SPRING that held the pick shut to improve the low end response. Could you just put a stiffer Spring in the hypergear one as opposed to changing to the BW?

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This is the one I used. The BW uses a tapered spring which gives better adjustability without losing too much stroke. But yes any CAN with a stiffer spring would work. The 3 pics above would be even better, being dual port you can hold the puck closed without upping your minimum boost limit. Best of both worlds. Boost control then needs to be setup as per external gate.

http://www.full-race.com/store/efr-turbo-accessories/borgwarner-efr-high-boost-wastegate-canister-2.html

Edited by BoostdR
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Ok it's now almost 1300rpm better spool. The issue with the Hypergear Rev 4 was the waste gate. I have a high boost Borg Warner EFR actuator with adjustable rod installed now. The difference in stiffness is probably 400% or more. Adjusting it this way does bring up minimum boost levels. An even better way would be a dual port wastegate like a forge item, the same as what the Bathurst R32 GTR ran. This would enable the gate to be actively held closed without increasing minimum boost. I had 20psi at 4700rpm in 3rd previously, I now have 20.4psi at 3431rpm in 3rd...and I'm currently on my BP98 tune not E85

Matt

attachicon.gifImageUploadedBySAU Community1449047925.206217.jpgattachicon.gifImageUploadedBySAU Community1449048214.636782.jpg

The benefit is a stronger spring holding the big puck closed before target boost is reached. Simple as that. It's like Scott's spring mod on steroids. The borgwarner can/spring is so stiff I can't move it by hand at all. Even very very hard with pliers. I can fully open the OEM can arm by hand without too much trouble.

I'm sure someone else was talking about this exact same thing a while back...

Oh wait; IT WAS ME! :thumbsup:

The tension of all springs increase as they are compressed.

All a variable rate spring would do; is allow the wastegate to unseat earlier.

I rather like the idea of a double acting actuator, and a 3 port boost control solenoid.

This allows you to hold boost pressure hard against the wastegate, holding it closed right up until the point you want the wastegate to open; when it switches the pressure signal to the opening side of the actuator.

Really glad you've seen an improvement in your response Matt; you must be wrapped after all the effort you've put in.

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I need all the response I can get back ;-)

The thing is the dual port gate might and might not work. If the exhaust pressure increases at a faster rate than the boost it will still leak. A stiffer spring being still required. It would still be an improvement giving a larger boost range but may only give back a few psi of control. In experience, the best way to response is adjusting the wastegate tension within a couple of psi of the target boost. Then use a closed loop boost controller like a HDI EVO that holds shut up to just before target boost.

My turbo makes 18-19psi in 3rd with the gate blowing open so not really any use targeting less than that. The exhaust housings on these turbos are just too small.

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Ive got a dual port on mine, cant say ive noticed any issues ither than a little more compressor surge at low boost than Id like.

That said ive got the bung in ome side and its set up fully recirculating so that could be why? New to the whole turbo thing so still learning

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Just need a stiff spring, the dual port will still help, but as you say Matt, the manifold pressure climbs much harder and faster than the boost. Relying on the boost to hold it back alone won't work, the spring needs to be as close to your desired boost as possible.

The other issue is the MAC valve, to work properly you need a 5 port which bleeds the pressure off each end of the actuator as it switches.

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On E85 today. Up a steep hill It managed 20psi at 3394rpm and I have some useable boost between 2000-3000rpm. Next issue to sort is the smoke when on boost. Not sure if it's fuel or oil as its not blue, white or black but a combination. Normal or common for a 35 stag? AFR's are around 12.2:1. Maybe my O2 sensor is too close to the turbo for high boost..and I am starting to wonder if the oil restrictor at 3mm is too large for 8.5bar of oil pressure. Easy to fix but I don't want to reduce the bearing life.

Tao, what size restrictors do you run in other cars with the same bearings? Oil pressure in most other cars is usually 2 bar less also.

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So Tao says 3mm oil restrictors are fine.

I cleaned the car and went for a quick run on 34psi(should pull 320-350awkw) by how it felt. Anyway the car back window is covered in black soot after 5min. Since my AFR's are ok I have a theory that the injector timing could be out, possibly an artifact of running the greddy ultimate.

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  • 2 weeks later...

Have been through few different high flows including OEM turbo on my M35 guinea pig so far. On problem with the M35 high flows is in the OEM wastegate. It is almost as Nissan engineered it to blow open at very low revs. I have installed a 20psi actuator to it using custom actuator bracket and the difference in response between EBC load is very noticeable.

New actuator assembly opens at a almost full 90 degrees, It makes a noticeable peek HP to a partially opened wastegate.

m35wg.jpg

Getting better transit response, I will be using ball bearing CHRA units, it does not require much oil to run and more then happy working with OEM oil restrictors:

photo3.JPG

Will update results once fully tuned.

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