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Old 06-13-2002, 04:41 PM   #1
kalogian
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Default low max boost press. in ludespeed II kit

Hi all-

I installed a Ludespeed stage II kit on my friend's 2000 RS. Initially, the boost pressure maxed at a solid 5psi. About 3 months later, we were getting only about 3psi max pressure. At first we suspected an exhaust leak, and we re-fit the up and down pipes to make sure there was no leak. I thought that maybe the spring in the Turbonetics wastegate settled, and was opening earlier, but tightening the adjustment screw to the maximum tightness doesn't seem to have changed anything. I'm thinking of one of three possible causeses.

1) A leaky connection to the boost pressure guage. We slipped the little plastic line from autometer into a t-d vaccuum hose and clamped it, maybe it's leaking some air and not showing the correct boost?

2)Maybe pushing air through the vapor canister? I think I had read something about this before.

3)Turbonetics warns about carbon build-up affecting the spring in the wastegate if the car is left idle too long. We've had the turbo kit installed for about 6 months, so I don't know if it could have fouled so quickly.

The fuel pressure seems about right: ~75PSI at 3psi boost pressure. Has anyone else experienced this or have any ideas?

Thanks.
Pete
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Old 06-13-2002, 05:03 PM   #2
kastle
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Is your friend using a Split Second Voltage Clamp?
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Old 06-13-2002, 05:41 PM   #3
kalogian
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Using one of the two zener diodes that came with the kit.
First we tried the 5.1V(?), and that kept turning on the MIL due
to sensor seeing to much pressure. So we switched to
4.7V (?) and that error code stoped showing up.
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Old 06-13-2002, 07:31 PM   #4
Aphex
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I too see the same thing, I haven't tried adjusting the screw on the wastegate yet though, waiting for my new clutch.

but mine is, when it's cold out, I'll see 5psi, when it's hot, only 3psi, my theory is that the vacuum line to the wastegate is flexing too much, I'm going to try replacing all my vacuum lines with those ricer color lines, heh heh, they have very thick walls and are supposed to be resistant to high temperatures hopefully.

if you take a look at the stock pressure lines, and the ones that came with the kit, the stock ones are very very firm, and don't squeeze easily, whereas the pressure lines that come with the kit can be closed off very easily by applying only a little pressure with your fingers. I meant to do this last night, but tonight I'll shoot off an email to tom suggesting thicker walled vacuum lines.
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Old 06-13-2002, 07:34 PM   #5
Aphex
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but then again, deltagate wastegates, aren't exactly known for their stellar boost holding properties, so who knows what's to blame just yet.
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Old 06-13-2002, 08:52 PM   #6
kalogian
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Hoses flexing might have been true before, when we had the wastegate set at 5psi (default), so it was missing 1.5 to 2 psi.
Now I supposetly set it at 7psi, so the boost is 3.5 to 4 psi bellow
what it should be.
Could it also be a bad turbine ?

I just tried the 5.1V diode also, no change.
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Old 06-13-2002, 11:21 PM   #7
Aphex
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it's possible that you have a boost leak somewhere, does the BOV seem to vent even on full throttle?
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Old 06-14-2002, 12:08 AM   #8
kalogian
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I tried to play with the BOV. If I turn it down, I hear a lot
of turbo flutter, but the boost peaks out at the same point.

How can I check what the blow off valve is doing at full throttle ?
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Old 09-05-2002, 11:14 PM   #9
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a bump here
I put the clamp today an I still getting no more than 2 psi of boost.... those any one know what do I need to check
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Old 09-06-2002, 01:51 AM   #10
Eric SS
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swap and N20. gone. : (

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I wish I had your problem. On my ludespeed kit, at 5-7psi boost, in 1-3rd gear is fine, but when I hit 4th and 5th gear, I can't keep it from going to 10psi

I would guess that you have some sort of leak somewhere. Maybe at an intake hose junction? Keep us updated. Look up and down the exhaust for signes of a leak (a lot of black residue). If you see none, it's not an exhaust leak.

Eric

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Old 09-06-2002, 01:52 AM   #11
Eric SS
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swap and N20. gone. : (

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PS, I'm sure you have adjusted the wastegate and BOV but sometimes the simplest things are what you don't think of so, did you check them?

Eric
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Old 09-10-2002, 11:07 PM   #12
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Eric you are right I have a small leak on the up pipe also find out that my autometer gauge wasn't reading ok
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Old 09-11-2002, 10:37 AM   #13
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Kalogin, do you have a cat? First thing i would check would be exhaust restriction pull the down pipe off and try to drive it on some back roads or something! warning you may become addicted to the noise/ sound of the exhaust! Jeff P
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Old 09-11-2002, 11:11 AM   #14
Aphex
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caution on that, you are most likely going to fry something in the engine bay, probably that main wiring harness loom going into the firewall, I'd have to check but I think the turbo exhaust outlet points almost directly in that direction, if you were going to try this, maybe get a pipe made to at least route the exhaust to under the car.
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Old 09-11-2002, 02:24 PM   #15
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Let me correct that statment, Remove the bottom of the down pipe! (as long as it doesn,t have the cat in it) At least remove 1 bolt and loosen the other so the flange cracks loose, and exhaust can get out. I'm not to sure what the set-up looks like.
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Old 09-11-2002, 04:43 PM   #16
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You should check the gauge first. I have had 4 people tell me that their Autometer gauge started to sit in the Vacuum when the car is off. if the needle is in the VAC when the car is off, then the peak boost is going to read low. I don't know why these gauges are doing this.
I just called Automete and they confirmed that it is becoming more common for this to happen. He had no explanation for it. I asked if there was a design change and he said 'no'. So who knows. Just a PITA to have to send them back to get them replaced.

Anyway, if the cat is clogged, you will notice a LARGE power loss. So if it doesn't feel like it is losing that much power, then it just might be the gauge.

Eric - one thing that I have noticed about Deltagates, is that they tend to creep if the adjustment is in far. I think that because the valve travel is SOOOO short, that the adjustment bolt decreases that travel by like 50%. So when you are under a huge load in 4th and 5th gear, there is so much exhaust energy coming out of the motor that the DG can't bleed enough off to regulate the boost anymore.
Have you tried loosening the adjustment bolt all the way out? If you have tried that and it still creeps to 10, then I dunno
Tom
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Old 09-11-2002, 04:54 PM   #17
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Tom, I'm having boost problems too. The gate is set for 6-7psi, and I'm only seeing 3.5 - 4.

I was guessing it was the wastegate, but someone also mentioned it might be the turbo. I checked the shaft for play, and there isn't any, the wheel doesn't spin very easily tho. Might be because it was damn hot, and I didn't want to burn my hand, so I didn't reach in very far.

You just brought up another point, my cat converter. Is there a way to check if it's clogged, and more importantly how do I replace it.

Joel
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Old 09-11-2002, 04:55 PM   #18
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The Deltagates have been known to creep at 10+ psi from what I've heard. Hence the reason I switched to a Tial 35mm.
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Old 09-12-2002, 12:53 PM   #19
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You may not notice a power pifference if the cat is starting to clog. Edwin's S4 was running low boost with nothing done to it. He also found the cat was starting to plug. The only real power difference is the lack of boost.
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Old 09-12-2002, 02:26 PM   #20
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Quote:
Originally posted by jeff22
You may not notice a power pifference if the cat is starting to clog. Edwin's S4 was running low boost with nothing done to it. He also found the cat was starting to plug. The only real power difference is the lack of boost.
Really. I just did a run with my deltagate disconnected, and it hit ~9psi before I let up, so the gate isn't stuck open. I think it's time to ask the muffler shop if they can take a peek.
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