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The mkiv Supra Owners Club

Stock boost...


Gaz Walker

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Cheers Guys,

 

I deffo get 9.9psi max with the boost controller off...

 

I have the SBC ID set up on channel 1 with volume to 58 and gain to 5 - this sets the boost to 14.1-14.5psi

 

I don't hit boost cut (boost warning is at 14.5, dials back boost when hit)

 

The cats are still in running stock exhaust (to be replaced asap!)

 

Also, I am getting a weird noise (only occasionally) when the 1st turbo spools at 1800 rpm+

 

Its strange, kinda sounds like like something clicking very fast - this happens when its set to Channel 1. When I turn it off it never makes the noise?

 

I followed the install instructions off MKIV.com...

 

Any ideas?

 

Gaz.

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Its strange, kinda sounds like like something clicking very fast - this happens when its set to Channel 1. When I turn it off it never makes the noise?

 

The clicking will be the solenoid from the boost controller pulsing on and off, trying to pulse width modulate the boost bleed. The way most boost controllers control boost.

 

 

 

I deffo get 9.9psi max with the boost controller off...

 

Sounds like only the first turbo is working.

You should get to 11psi with boost controller off. This is the stock setting. Take a peak at the hoses in the car (especially the tiny 4mm ones) and check non have come off. Look close by the exhaust downpipe for a small vacuum valve and control valve. Sometimes this 4mm pipe comes off and you loose turbo 2 control completely.

 

Pete

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hi, matt the clutch is now very poorly ,unfortunately so is the bank account. so at the moment its just sat there until payday then going to have a chat with whilfbliz for a new one. iam using a turbocharge heat seeking missile van with all of 75 bhp at the moment .......... and its faaaaaaaaslowwwwwwww. at 60 miles to a gal, its ok for a saving spree. how are you coping these days then ? good i hope ? those wheels of yours are starting to look a bit shabby and worn , i think you need a new shinny set, so ill take the old ones off you :-))):D ....TRL has diagnose the problem perfect but what if the 4mm hoses are blocked? what would that do? because i think mine are ??i get about .7 bar until the 4 thousand then it goes to 1.35 does this sound ok?

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TRL has diagnose the problem perfect but what if the 4mm hoses are blocked? what would that do? because i think mine are ??

 

I'd hope they weren't blocked as this would mean that at some point contamination has got into the clean filtered air?

 

Blocked or fallen off, the effect will be the same. The exhaust bypass valve will not operate and thus the exhaust gases will not be routed around the second turbo and will not spool (spin) the turbo.

 

i get about .7 bar until the 4 thousand then it goes to 1.35 does this sound ok

 

Sounds like the second turbo isn't pre-spooling at all and being slamed into action. Hard to tell without actually seeing/hearing it.

 

Your best bet is to take off every little and large air pipe you can find. Replace with nice new pipe, or at least check for splits, holes and blockages(?). Make sure they are secured tightly, using cable ties or proper pipe fixings. Don't rely on the old hardened plastic pipes and the warn out fixing clips. They may well all be a bit tired. Especially if the car is an older model Supra. (Make sure they are air pipes and NOT water pipes!!!)

 

You should also get your VSVs checked out. They are the Vacuum Switching Valves, turned on with 12V, they should be OPEN (so you can blow through the either pipe). 0V or disconnected the VSV should be closed (so you cannot blow through either pipe)

 

 

You've really got to get all this checked first as tiny leaks from many pipes add up to a lot of lost boost pressure.

 

Regards

Pete

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Akshully, I think you can blow into the exit port of the VSV when they are shut, and the air exits via the wee cylindrical filter. I assume this is to relieve pressure or something. Might be wrong, but I don't want anyone thinking all their VSVs are wrecked by accident :)

 

Lack of prespool would be the Exhaust Gas Bypass Valve not being opened. If you go to Resources -> Technical Reference -> Turbo Pipework Pictures, you can see all the suspect pipes in glorious technicolour (and fairly hideous blue, sorry about that :) )

 

General Turbo Pipework (rear) has the EGBV plumbing, but I can't seem to get more than the top bit of the image on my box - hopefully it's this PC being rubbish and not something up with the image. The Vacuum Path diagram is rather useful as well for tracing what goes where.

 

-Ian

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Originally posted by Ian C

JB, if you see this, can you take a look, please? If I arsed it up and you need the piccy resending, let me know.

 

-Ian

 

It was probably me, I ran the website out of space so it stopped upping the file and just stopped. I cleared out some chaff and reloaded the pictures it hadnt done but that one was obviously corrupt. I will sort it this evening.

 

I also removed a 70mb mysql backup so I should now have room for the injector pictures.

 

JB

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