Neilo

Would this allow the turbo to spool up quicker? i believe that i have a 2 1/4" up pipe and a full decat 2.5" turbo back but sometimes the turbo seems lazy and the spools not that quick (APS SR30), on another car where the turbo originally came from the spool up was fairly rapid from what i remember, the only variable that i can think of being the fact that he had a full APS exhaust 3" and possibly an uppipe from the same manufacturer.

Alternatively would a decent set of headers assist?

Delboy2

A larger bore Up-pipe will make the turbo spool more slowly (Larger bore will reduce the gas velocity) but would be better for top end power
A decent set of headers will improve the gas flow or if on a budget have the oem headers ported

Cheers

washer

put a megan on it m8 you will see a again ,25bhp + @6000rpm not bad for 250 quid

RB5_245

all the above will reduce spool up though, what are you using for boost control? A daws device will give about best spool up your set up is capable of (as good as an expensice ebc).

Dave

Neilo

its a tek 3 map @ 1.4 bar, boost controlled by 3 port solenoid, no 3rd party controller used....rb5_245, can you explain how the spool would be slower?

RB5_245

The ecu alters the wastegate duty cycle as the boost rises effectively pulsing the wastegate, this 'slowly' brings the boost up the the target. The likes of an avc-r does this faster.

A dawes device holds the wastegate shut until the target is reached then opens in suddenly, a bit more crude but lets the turbo spool up as fast as physically possible.

Dave

Neilo

how would a dawes work with a 3 port solenoid? ive had a dawes in the past and it was very good but that was only with the 2 port.....any ideas?

RB5_245

it won't make any difference in what solenoid you have, the dawes will by-pass it. If you're not sure about it borrow one for a few days, and make up your own mind about it. The downside of dawes is it naturally tails of the boost at the top end which may annoy some people.... however it would be recommended to tail the boost of at the top by most mappers anyway..

If this makes no sense I did type while drunk and will make a better effort in the morning....... if I stil know who I am

Dave

TARManiAC

I thought one of the advantages with a Dawes was the capability to hold boost higher for longer than the ecu.

R19KET

If the boost is tailing off, I doubt it will be down to the Dawes, unless the spring is being effected by heat.

More likely, the turbo is too small for the boost being run at the higher RPM.

Running a turbo that far beyond it's efficiency, "loses" power, due to excessive charge temps.

Mark.

RB5_245

Actually it is down to the dawes, not due to heat though. It will give you full boost in every gear and tail it off at the top.

When I first fitted the TD05/06 to my car I was running 1.0bar boost, probably only 280ish bhp with the dawes. In this state the turbo is not even slightly being tested, yet the boost tailed off at the top (I don't remember to what pressure, it was a long time ago). After re-mapping and having the Gems control the boost it held 1.3bar to the redline, before it was set up to tail off to 1.2.

I think the boost tail off would be governed by the size of the vent hole. This could be increased to alter the charateristics of the boost curve (spool up remaining the same).

By my thinking if you were to increase the size of the hole, while keeping the same spring tension you would reduce the tailing off. By venting more air the wastegate will be further shut. However when the boost builds, if you vent too much air you'll overboost in the midrange.

I may be slightly out with my theory here but I think that's the principals.

Dave