New IC

[audiman]

Good work Dougal. I have ordered those SS bends for you today, so will post them ASAP. I have fitted one of these IC's and i dont notice much in the way of extra lag if any. But then i changed turbo's at the same time so im unsure.

[Doug_RS2]

Well i was expecting a slight pressure drop, and it turned out to be about 0.1bar

Martin - how do you know you had that pressure drop? Have you measured it?

I was speaking to Mihnea about my turbo, that is on Toms car just now, and Toms car has stopped making the pod racer sound from the wastgate pipe - only thing we can think of was his turbo was surging - pulsing to cause it - I think Mihnea said you had surging at some point?

[martinjs]

Well just before i took the old i/c off it was running 1.5bar, mihnea set it at this at gregs garage meet because its not much use running more with the crappy 3b i/c.
So got the new i/c fitted and dropped to 1.4bar.
i was wondering how to check the pressure at the turbo outlet and compare it to inlet manifold pressure?. could this be done via the wgfv take off on the coldside with the connector unplugged from the wgfv, i know it will only be wastegate spring pressure but could get an idea.

[martinjs]

I am still getting surging yes, i think it is the d/v. Ive tried all the different springs you can get for it + new piston (forge) seems to happen less with the strongest spring in but it still does it.
Im gonna try an S3 one.

I cant understand how it can still happen, no-one else seems to have this problem with these d/v's.

[Doug_RS2]

Martin - I don't think it is the diverter - I have never had surging problems with my forge - and I run the standard spring - the way it works means it shouldn't surge - you should always have the manifold pressure on the vacuum line to it that should match the boost pressure in the outlet hose - so the pressures are always matched - unless there is a big pressure drop!

It could be that you have increased the volume that much with your new IC and pipework that it is causing the surging now? I don't know too much about this - need to speak to mihnea about it. The new IM will help.

You can put a t-piece in the WGFV hose to the compressor outlet and connect your boost gauge to that - see what you get and then compare that to the manifold pressure. You could be getting a lot more boost at the compressor outlet - you boost gauge always measures the inlet manifold pressure. I think it is worth doing!

Do you have a seperate wasgate pipe? Do you get the pod racer sound like Toms car?

[martinjs]

Do you have a seperate wasgate pipe? Do you get the pod racer sound like Toms car?

No i dont have one yet, i want one though.
mihnea did say my turbo sounded a bit strange, worn maybe.

i'll look into testing the pressure then.

[martinjs]

it was surging with the stock i/c on, not quite as much though

[Jeffer]

it was surging with the stock i/c on, not quite as much though

Sorry to go off topic guys, but is there a media file where we can hear the open wastegate sound? I'd like to know what i can expect

Cheers

[Jay]

it was surging with the stock i/c on, not quite as much though

where have you taken the waste-gate signal from? I had surging which was made better by the over boost valve being removed and finally cured by 'T'ing into the inlet pipe before throtle housing. i think this was caused by turbo surge made worse by the length of the inlet track.

Jay

[Jay]

where have you taken the waste-gate signal from? I had surging which was made better by the over boost valve being removed and finally cured by 'T'ing into the inlet pipe before throtle housing. i think this was caused by turbo surge made worse by the length of the inlet track.

Jay

P.s you get a over-boost effect from moving the boost signal away from the turbo compressor outlet so you may have to lower the pretension on the waste gate spring.

[Doug_RS2]

Sorry to go off topic guys, but is there a media file where we can hear the open wastegate sound? I'd like to know what i can expect

I have a video clip of Tom (pod racer sound from seperate wasgate pipe) me (seperate wasgate but no pod racer sound) and Martin driving past all in a line on track - It might be easier to ask Tom for it - becasue my pc with it on when t1ts up. I might have it on CD - I will look tonight.

I never really noticed a noise difference on my car - apart from driving near a wall with the window down. Toms sounds like a jet engine, starting and stalling, and scares the **** out of old people.

[Doug_RS2]

Jay - I am confused by your statements - the Wastegate (through the WGFV) uses the compressor boost pressure from the nipple on the turbo housing.

What have you done to your car? What spec is it? Have you removed the WGFV and just using the spring?

[Mihnea]

Doug and Martin, the compressor housing nipple for the WGFV won't give you pressure at the compressor outlet but way less pressure, even with the WGFV connected, while the car is still making normal boost. BTDT unfortunately. The only way to do this is to make a metal pipe with a nipple fitting on it so you can connect a boost gauge to it.

Martin, I'm not talking about your surging on throttle lift-off (compressor stall actually or something like this) but rather about the pulsing sound your turbo makes when on full boost at low revs. This is caused by high pressure drops and maybe a loss in volumetric efficiency (dunno how the IC affects that tho, never toyed with that idea) and the turbo is running in the surge line on the compressor map...


cheers,

Mihnea

[Pisobiker]

Martin this sounds odd to me.
Given the ECU takes the boost signal from the IM, if Mihnea setted boost to be 1.5 max then it should stay that way no matter of the pressure drop before the IM. If you have a bigger total pressure drop in the ilet tract (lets say 0.3 bar instead of 0.2) this only means your turbo will be forced to run at a PR of 2.8 instead of 2.7 (supposing P1=1000 mBar) to have the IM @ 1.5 bar relative.
Still confused on how our ECUs "brain" really behave.


Marco

Well just before i took the old i/c off it was running 1.5bar, mihnea set it at this at gregs garage meet because its not much use running more with the crappy 3b i/c.
So got the new i/c fitted and dropped to 1.4bar.
i was wondering how to check the pressure at the turbo outlet and compare it to inlet manifold pressure?. could this be done via the wgfv take off on the coldside with the connector unplugged from the wgfv, i know it will only be wastegate spring pressure but could get an idea.

[Stick Insect]

Have you been taking lessons of bodging from Tom? I think Iwould prefer the 2 straps underneath going to something - not the engine as it moves! - have to be bodywork off to the sides.

Yup..

seriously though the bumper bottom would provide location to the I/c. If you have a smash and damage the bumper the Intercooler is history anyway. The only thing to do is to make the I/C crossmember a square shape and support it that way. There isn't much in the way of stuff to fasten onto around there.

David