"First Turbo Mod" - Thread?

[michael]

I'm looking for a thread or a website with info on the "first turbo mod" - I've used the old search button and looked on mkiv.com but can't seem to find a definitive source of info that explains the mod.

I have the necessary bleed valve, T-pieces, hoses etc that are required to do the mod thanks to Mr Lane but just wanted to have a read up prior to having a go.

Basically I want to increase the boost on turbo 1 and increase my overall boost to 1.3 bar when I get my turbos and ARC SMIC fitted next week.

[Paul Laing]

I wouldn't do that mod mate, do some searches on that mod, many people say that it jump starts the second turbo way to quickly and can damage the turbo. Just a heads up.

Paul

[michael]

I've done a few searches Paul and no obvious threads are jumping out on me - I'm at work at the mo and can't really read through the threads that do come up to look for a drift to this topic... I'm intrigued to know more about the problems though, seemed like quite a sensible mod to me :)

[Paul Laing]

I've asked it a few times on Supraforums but they all say don't do it. I had Michels mod on my car for a while, but not having my car Bpu made this pointless, but it does make a bit of a difference, but it doesn't spool up your 2nd turbo, it just comes online straight away with this mod....which can make the life of the turbo last less, not sure how less though

Paul

[Paul Laing]

Does anyone know how much it damages the 2nd turbo? If it's not much then i might think about doing this mod, as it was good :)

I just don't want my 2nd turbo to go pop.

[Ian C]

http://www.mkivsupra.net/vbb/showthread.php?s=&threadid=2889&perpage=15&highlight=blue%20spaghetti&pagenumber=2

I remembered someone called my setup "blue spaghetti" so I searched on that :D

-Ian

[Ian C]

Just make sure you don't go mad on the 1st turbo, 0.9bar is as high as I'd take it.

-Ian

[michael]

Originally posted by Ian C
http://www.mkivsupra.net/vbb/showthread.php?s=&threadid=2889&perpage=15&highlight=blue%20spaghetti&pagenumber=2

I remembered someone called my setup "blue spaghetti" so I searched on that :D

-Ian


And I was just about to PM you for some input after finding that very thread :)

[michael]

Originally posted by Ian C
Just make sure you don't go mad on the 1st turbo, 0.9bar is as high as I'd take it.

-Ian


This might be a dumb question (most of mine tend to be) but how will I be able to check the boost level on the first turbo alone?

I currently rely on the AVC-R output to give me boost readings as I don't want any additional clutter in the cabin - the bleed valve and associated gubins I have to do the mod is preset to 1.1 bar apparently.

So do I just drive while monitoring the boost and when the second turbo comes in make a note of the boost level it had peaked at? (I can record the boost map on the AVC-R for playback).

[michael]

Originally posted by Paul Laing
I've asked it a few times on Supraforums but they all say don't do it. I had Michels mod on my car for a while, but not having my car Bpu made this pointless, but it does make a bit of a difference, but it doesn't spool up your 2nd turbo, it just comes online straight away with this mod....which can make the life of the turbo last less, not sure how less though

Paul


I'll pop over to Supraforums later on for a read - I'm trying not to spend too much time on there as I'm hooked on enough forums already :)

[Ian C]

Originally posted by mcanny
This might be a dumb question (most of mine tend to be) but how will I be able to check the boost level on the first turbo alone?


Watch your boost gauge but don't go about 4000rpm :) The manifold pressure is measured, and that cares not how many turbos are feeding it air.


I currently rely on the AVC-R output to give me boost readings as I don't want any additional clutter in the cabin - the bleed valve and associated gubins I have to do the mod is preset to 1.1 bar apparently.

So do I just drive while monitoring the boost and when the second turbo comes in make a note of the boost level it had peaked at? (I can record the boost map on the AVC-R for playback).

You don't need to do anything as complex, just boot it in say 5th at 2000rpm, lift off at 3500 rpm, check the peak boost pressure you got, that's what tubby 1 is producing.

In my experience you don't need to open the bleed valve much at all. Start with no more than one turn.

-Ian

[michael]

Cheers, I'll give it a whirl and see how I get on :)

[Paul Laing]

Thing is, won't the Boost change with the temperature? I would put on a Boost Gauge

[outatime]

Originally posted by Paul Laing
Thing is, won't the Boost change with the temperature? I would put on a Boost Gauge

:confused:

Temperature? I think you are confusing a boost gauge with a thermometer...

[Paul Laing]

No, when the temperature outside changes the boost will be different, thats what happens when you fit a bleed valve isn't it?

[Steve W2]

Yes, the pressure changes slightly with temperature but as long as you read the manifold pressure at the same point the car is running its normal pressure you will have a relevant reading (providing you drive as Ian C said, i.e below 3500RPM).

:)

[michael]

Colder, denser air can cause you to get more boost but that will happen regardless of what I have to monitor the levels, the boost gauge will go higher, the AVC-R will read higher... they will still both show the actual boost levels :)

[outatime]

Ah, I see.

Just test it early on a cold morning :)

[Ian C]

Yeah, you can get more boost on colder days, that's why you need to keep tweaking the bleed valve as the weather improves :) You need a good 10degC change before it's noticeable though.

I think a boost gauge is already in place Paul, it's the Apexi AVCr that Mcanny has been mentioning he reads the boost pressure off.

-Ian

[Steve W2]

Originally posted by mcanny
Colder, denser air can cause you to get more boost but that will happen regardless of what I have to monitor the levels, the boost gauge will go higher, the AVC-R will read higher... they will still both show the actual boost levels :)

Thats what I meant to say but I went to the pub for 1.5 hors at lunch:burp:

[outatime]

Originally posted by Steve W2
I went to the pub for 1.5 hors at lunch

Is that supposed to be 'hours' or 'whores'? :innocent: :D

[Steve W2]

Originally posted by outatime
Is that supposed to be 'hours' or 'whores'? :innocent: :D

:D :D The second one!!

[Ian C]

Watch it guys, this is a technical thread and Terry Saunders is now the moderator :) Have you seen the size of his Twak stick?!

-Ian

[Steve W2]

Originally posted by Ian C
Have you seen the size of his Twak stick?!-Ian

:eek: :looney:

[Paul Laing]

Doesn't his boost controller only tell him the boost of the 2nd turbo? he needs to know what the 1st one is at

[Alex]

Manifold pressure....that's what is measured by ANY device displaying boost pressure.

[Ian C]

Originally posted by Ian C
Watch your boost gauge but don't go about 4000rpm :) The manifold pressure is measured, and that cares not how many turbos are feeding it air.

-Ian

Cough cough :music: :)

-Ian