Boost problem.

[Yakozan]

I went out and tried to setup the EBC yesterday and have some small problems with the boost.

When I'm in 5-6th gear and floor it the car boost about 0.5Bar. This can be changed with the EBC though. Problem is that when the revs rise, so does the boost. It keeps doing it slowly to about 0.82Bar.

If I floor it from third starting from a higher rev. The car boost very quickly to about 0.78Bar and rises with the revs to 0.82Bar.

Even with the EBC off the car boosts about 0.8Bar when flooring it in high revs.

What could be the problem?
I'm thinking about putting back the stock boost solenoid and t the new one in.

This is my first turbo-car. So I'm not really sure how boost is supposed to come.
But I thought that I should have full boost anytime a go full throttle?

 

[Meddy]

Ok mate now its early so if I dont make sense I apologise. This boost creep with revs is common at least three people in the UK I know of have mentioned it when fitting a filter and exhaust to a stock car. Mine used to hit around a bar on the stock gauge.

The boost controller should be able to deal with it though. Im just wondering if your having problems as the pressure your trying to control to is so close to the actuator set pressure.

So first question is what happens if you set the controller to say 0.7 and then do a run? The same thing?

 

[S15R]

full throttle doesnt mean full boost, full boost depends on rev and gear

stock starts boosting hard after 3.5k ~ 4k rev
hks actuator/EBC will help to get to your boost up sooner

with hks actuator, lowerest boost you run is 0.9ish bar

 

[Nicely]

I've not tinkered about with boost at those levels, so I'm not sure if the same thing will happen. Think everyone knows about my 1.05 bar boost creep.... Well, 'creep' as in an explosive type way...

I hit peak boost around 4k rpm in 5th and 6th.

 

[Yakozan]

I tried setting the boost higher. But when starting to hit really high revs the warning came on (set at 0.9Bar)
So I reduced it. The gain was set higher at the time (5)

By the way. now the EBC is set at about 35 and the gain is 2
And now it's only creeping up to 0.82Bar and then stops there.

Isn't the actuator set pressure about 0.5Bar?

 

[Nicely]

If its an SBC, you should be setting the gain to about 5, and working out the boost from that.

Guidelines on setup are here.

 

[Yakozan]

In 5-th gear running about 2500rpm and flooring it. I get about 0.5Bar of boost and it holds that untill getting into higher rev ranges.

So it's supposed to do that, and then climb with the revs?

 

[sushiming]

thats right normally 3k rev u get 0.5/6 bar and after 5k rev u get about 0.8 bar no matter what gear ur in

 

[Yakozan]

thats right normally 3k rev u get 0.5/6 bar and after 5k rev u get about 0.8 bar no matter what gear ur in

Well If that's the case. I don't think there is a boost problem

Then there's only the final adjustments to the EBC.

Does the gain make the turbo spool earlier or just faster?
I can't really imagine the turbo to spool faster though. When downshifting and flooring it it spooled hella-fast.
My friend was shocked Thank you BB turbo

 

[Nicely]

If it doesn't boost beyond that level, that's fine. Its only really a problem if something like a one point shift in the boost setting causes the boost to shoot up to 1.3 bar....

BB turbos spool very quick. However, I would set the GAIN to 5 and slightly adjust the SET, as that is the recommendation.

 

[Yakozan]

If it doesn't boost beyond that level, that's fine. Its only really a problem if something like a one point shift in the boost setting causes the boost to shoot up to 1.3 bar....

BB turbos spool very quick. However, I would set the GAIN to 5 and slightly adjust the SET, as that is the recommendation.

OK. I'll adjust the gain and see what boost I get and go from there.

It's good to know that the car boosts as it should.
I thought my actuator could be stuffed or something.
But now I know that the car is supposed to boost less when driving in low revs.

 

[Topper]

When i read your 1st post, i didnt see a problem, as far as i know that what there meant to do :nod:

I've yet to have my Greddy setup correctly, on half throttle ghey there is alot of hissing and a little boost spiking, hopefully once its setup that wont happen :thumbs:

 

[Meddy]

You all seem to have loads of hassle with your boost controllers. :nod:

Just buy a HKS one and it does it all for you with no spiking.

 

[Topper]

Yeh but yours is prob setup correctly, where as mine is not :no:

I have every faith that if even I set it up correctly it would work fine :nod:

 

[Nicely]

You all seem to have loads of hassle with your boost controllers. :nod:

Just buy a HKS one and it does it all for you with no spiking.

I have no problem with mine. It holds rock solid.

My spike occurs any time boost goes over 1.05 bar. Does it with the controller off and running on just the adjustable actuator...

 

[Meddy]

Hah I was only kidding your all very touchy today.

 

[Yakozan]

When i read your 1st post, i didnt see a problem, as far as i know that what there meant to do :nod:

I've yet to have my Greddy setup correctly, on half throttle ghey there is alot of hissing and a little boost spiking, hopefully once its setup that wont happen :thumbs:

It's my first time tampering with boost in my life. So I didn't really know how it was supposed to act.
The blitz unit is very easy to setup when you have an english manual

What I don't understand is why the spool up on a stock S15 is so slow?
It's way faster now with the EBC connected, even with my low gain setting.

 

[Nicely]

Too faster spooling = spiking.

Meddy, you'd be touchy if you had to replace your turbo to stop it spiking.

 

[Meddy]

Too faster spooling = spiking.

Meddy, you'd be touchy if you had to replace your turbo to stop it spiking.

 

[Topper]

[It's my first time tampering with boost in my life.....................

Me to mate :nod: Were all learning - well, most of us anyway :thumbs: