Tuesday, May 25, 2010 - 10:11 pm, by: Scott Wilkes(Scottywilkes)
ok so heres the story.
Ive got a AVCR hooked up to the standard twins.
Exhaust system comprises of Lews seperated wastegate dump pipes, then into 3 inch stainless mandrel bent straight through exhaust into twin 3 inch pipes out both sides into blitz nur mufflers.
The system is Extremely! highflow as was made specifically for this, literally no backpressure.
Ive had the turbos and manifolds off and ported the exhaust manifolds and the turbo exhaust inlet out for maximum flow.
Problem im having and what i believe is that the wastegates are at there maximum flow due to the exhaust exhaust gas flow and no backpressure in the exhaust.
Both actuators are still good and open fully at full boost.
Im kicking my self for not porting out the wastegates in the turbos when i ported the rest.
As it is, natural boost is 1.3 bar, aka about 20 PSI, this is with the AVCR disconnected.
Which is fun none the less, the old soarer breaks into wheelspin in 2nd on the highway easy (its a manual) but wouldnt mind managing tis a little better. Any ideas?
The turbos have been taking this punishment fine for the past 6 months and seem to love it haha.
Wednesday, May 26, 2010 - 10:58 pm, by: Rob Rojo(Rob_tt)
Try hooking the actuator line up to the pressure side of the turbo as factory i.e. without the boost controller and excess length hoses. It could be as simple as a blocked or kinked boost hose.
Thursday, May 27, 2010 - 07:05 pm, by: Chris Prak(Carizma)
That sounds pretty normal with all the porting and what not. I only had Lews dumps, full 3" exhaust, cooler, filter and it would creep up to 1 bar easily. I don't think theres a way to reduce boost other than to restrict airflow.
Friday, May 28, 2010 - 04:56 pm, by: James Wilson(Ser493)
Also check that the rods that open the wastgates have not been bent. Tuners sometimes do this to generate higher numbers - stops the gate opening up as much. I have seen a couple of different workshops do this as dodgy as it sounds. They just stick a screw driver in between and give them a bit of a bend....ugly and dodgy in my opinion.
Friday, May 28, 2010 - 06:53 pm, by: Scott Wilkes(Scottywilkes)
thanks for the ideas fellas, going to have a fiddle this weekend and see what i cando.
The actuator linkages havnt been touched james, ive had it for the last 1.5 years and the problem only began after i did all the exhaust work ( im an apprentice mechanic and no one touched my car but me haha)
Anyway going to connect the actuators directly to the snails as rob has suggested and then that should rule out any external problems and only leaves me with the option of ripping the turbos off to enlarge the wastegates
Wednesday, June 02, 2010 - 07:19 pm, by: James Harris(Haro)
I agree with what chris said. All that 'free flowing' is only going to result in one thing... BOOOOOOOOOOOOOOOOOST!!
I had the same problem of hitting boost cut when I installed my Lew's Dumps and straight through exhaust ( de cat). Even after installing a FCD the boost would easily run 1.3+ bar...
Having an EBC is not going to lower the boost in anyways (impossible). The best boost controller is your right foot my man.
Once those turbos die... replace em with some high flow steelies and enjoy the 1.3+ bar all day every day.
Wednesday, June 02, 2010 - 09:12 pm, by: Scott Wilkes(Scottywilkes)
got a GT35R on the cards james
The standards love the boost, i cant justify spending over 3K on getting some steelies when the ceramics take it day in day out fine as long as you source a good set and have appropriate mods. Id rather replace a few sets of standard twins than get steelies haha.
I connected the actuators directly to the snail and the lowest boost i can get is 1.2bar haha, so i gotto admit the exhaust work definately made a heck of a difference
Thursday, June 03, 2010 - 05:58 pm, by: Rob Rojo(Rob_tt)
I would be very surprised if your making 1.2 bar with properly functioning wastegates even if they are flowing freely and ported etc, my bet is one of the actuators are stuffed and not allowing the wastegate to open. If that doesn't fix it it might be worthwhile fabricating an external wastegate setup.
Thursday, June 03, 2010 - 06:39 pm, by: Scott Wilkes(Scottywilkes)
ive had a pressure gun on it (same thing as multivac but adding pressure) and they are fully open at 9psi both of them and hold the pressure without leaking.
So the gates are fine. The boost creeps as the revs rise, it raises to roughly 1bar then peaking out in the revs it creeps up to 1.2
Friday, June 04, 2010 - 11:47 am, by: James Harris(Haro)
GT35 = nice - just buy a 14psi spring for your external wastegate and then add a boost controller for those off occasions you want even more boost.
Please also buy a QUALITY wastegate (tial etc) and not some dodgy copy one as although most of em will work - - the ones that dont work end up costing you a fortune in stuffing around.
oh and also dont be gay.... utilise a screamer haha
Friday, June 04, 2010 - 11:53 am, by: Rob Rojo(Rob_tt)
It strange that the boost would peak at higher revs being only small turbo. Unless the Acutuators have a leak and loose pressure, how long did you hold the pressure on?
Saturday, June 19, 2010 - 08:01 pm, by: Scott Wilkes(Scottywilkes)
well took the turbos off again today, 4th time or 5th? cant remember lol,started at 12 noon got the turbos and lews dump off, removed rear housings from turbos, ported the wastegates out by 2mm, went had lunch, cleaned housings of all metal filings, refitted to turbos, retested actuators, refit turbos to car and refit lews dumps, drive out of the workshop at 6.30pm.
And im pleased to say im now holding a steady .9bar at full throttle throughout all gears , extremely happy, time to refit the AVCR and crank that up to 18 psi woot
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