How to raise turbo boost

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garyo
Posts: 57
Joined: Wed Jan 16, 2008 12:38 am
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Vehicle: 91 exceed
Location: north van

How to raise turbo boost

Post by garyo »

hello everyone.

I finally got around to a project that i've been thinking about for a while.
How to adjust the turbo wastegate to 15 psi, (or more ), without the blowoff valve going off ?
Mine was dumping at 13 pounds.My wastegate was set to 12.
Everything was fine, then with the snorkel putting cold denser air into the engine,I could hear a whistle at full boost.

It seems that the colder air upped the boost slightly,just enough to unseat the valve.This is what caused the whine
that I was blaming the snorkel for.

I made a thing ( dont know what to call it),that clamps onto the pressure relief valve on top of the intake manifold.
It has another small spring to help the original one .
The bolt in the center can also be tightened down to completly eliminate it blowing off at all.
When I tested it with shop air, I tried a few springs untill I found one that caused it to release at around 19 to 20 psi.
then adjusted the wastegate to dump at 15.

As always ,watching the pyro. backing off before 1000 deg. post turbo.

The van seems to pull a little harder now.

gary
Attachments
this clamps onto the weak pressure relief valve on top of intake manifold.jpg
this clamps onto the weak pressure relief valve on top of intake manifold.jpg (87.67 KiB) Viewed 6707 times
installed on engine, with spring in place.jpg
installed on engine, with spring in place.jpg (117.07 KiB) Viewed 6703 times
peterh
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Vehicle: 95 L400 Delica Super Exceed
Location: Brisbane, Australia
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Re: How to raise turbo boost

Post by peterh »

garyo wrote:hello everyone.

I finally got around to a project that i've been thinking about for a while.
How to adjust the turbo wastegate to 15 psi, (or more ), without the blowoff valve going off ?
Mine was dumping at 13 pounds.My wastegate was set to 12.
Everything was fine, then with the snorkel putting cold denser air into the engine,I could hear a whistle at full boost.

It seems that the colder air upped the boost slightly,just enough to unseat the valve.This is what caused the whine
that I was blaming the snorkel for.

I made a thing ( dont know what to call it),that clamps onto the pressure relief valve on top of the intake manifold.
It has another small spring to help the original one .
The bolt in the center can also be tightened down to completly eliminate it blowing off at all.
When I tested it with shop air, I tried a few springs untill I found one that caused it to release at around 19 to 20 psi.
then adjusted the wastegate to dump at 15.

As always ,watching the pyro. backing off before 1000 deg. post turbo.

The van seems to pull a little harder now.

gary
Great mod 8-) 8-) 8-)
Peter

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delicat
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Vehicle: '92 Exeed '93 Safari '94 Pajero
Location: New Westminster, BC
Location: New Westminster, BC

Re: How to raise turbo boost

Post by delicat »

Hey Gary,

I have something similar on my van that Shaun made a while back. My boost is now set at 17psi but it usually max at 15psi. Doing so kept the EGT a little bit lower, just a little.

Then with the snorkel it now feels like I have another turbo under the hood. I took my van to go wheeling in Mission today and for the first time I stayed in the fast lane the whole way. Even when pushing hard, the van only goes up to 900 degree (after turbo), maybe 950 on an incline and if only cruising to 90km/h it's down to 700. Acceleration is also much better. Never thought it would make such a difference! Turbo spools quicker too...

I like how you came up with this mod, looks really clean and efficient! (As usual).

Happy new year!
D.
'93 Nissan Patrol
'94 Mitsubishi Pajero
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"If it ain't broken, modify it!"
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garyo
Posts: 57
Joined: Wed Jan 16, 2008 12:38 am
Member's Photo Album: http://www.delica.ca/Photos/
Vehicle: 91 exceed
Location: north van

Re: How to raise turbo boost

Post by garyo »

Hey David

Great minds think alike. :twisted:
the numbers sound about the same for mine also.
I really have to abuse it to reach 1000 deg.
the snorkell and more boost helps make more power than expected.

Drop by the shop sometime, so we can compare.
I dont have a phone, and lost everybodies #'s

gary
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