dan1200sss ca18det datsun 510

[dan1200sss]

Oh and currently Iv got a shit old no brand boost gauge Iv had floating around In the garage for ages untill I allow my self a EBC/digital boost gauge back on it after run in is over... The gauge Is accurate enough tho, Iv borrowed a mates new vdo one to compare and there close enough I'n accuracy. I tried plumbing it both in before and after the TB. Same boost reading. Ka24de TB so 70mm I believe

[torqued]

The vacumn side of the wastegate. what is that plumped into?

Whats the vacumn part of your boost guage read at idle? is the needle steady?

And am i correct to say changing the ex-wastegate made it jump 2psi?
What is the size of this gate?

[dan1200sss]

the side port of the gate is plumbed into the start of the intercooler pipe, close to the turbo.
sits at 20 vac at idle, steady as.
i think so, allthough it seems to be inconsistent with boost , ranging between 0-5psi and drops off higher in the rpm. pulls decently hard and very very smooth tho.
its the new MVS v-band 38mm tial ( watercooled diaphram )

[torqued]

Is boost higher in 3rd gear and when going up hill?

[dan1200sss]

yep 3rd is higher iv noticed. havent been up hill yet tho

[gingofthesouth]

Just for shits and giggles have you disconnected the hose from the waste gate (also blocking the feeder hose as you dont want a massive leak lol) and checked carefully if it free boosts? That could rule out wastegate issues.

[dan1200sss]

Lol Sure have. Didn't free boost, stayed the same so the wastegates not at fault..

[Bartman]

Does it pull strong otherwise? The only other things that can cause weak boost is timing being out, and knock sensor fault.

[dan1200sss]

I'm positive I set timing to 10 degrees. Double checked it. Fuk yeah pulls strong and smooth as a school girl

[85_Z31]

10 degree's BTDC sounds quite low is this nissan spec or have you set it to 10 deg for another reason ?

When i had my timing that low on my Z boost response was terrible and EGT's were very high. When i ran my timing at 20 Degree BTDC it became a whole new animal, tons of power and EGT's were 300deg cooler.

As for a knock sensor fault quite often you can unplug the knock sensor and put a resistor in its place to simulate a known good knock sensor for testing purposes.