Brand new MD321T not holding boost, any suggestion?
#1
Scooby Regular
Thread Starter
iTrader: (3)
Join Date: Dec 2005
Location: MY 98 STI 4
Posts: 490
Likes: 0
Received 0 Likes
on
0 Posts
Brand new MD321T not holding boost, any suggestion?
Fitted on STi version 4 with 2.5 conversion.
Here are the details:
My 2.5 conversion was done over 12 months ago & the old turbo was holding boost fine. This weekend I fitted an MD321T and headers (which I skimped on via ebay).
Here's the problem:
It can boost up to 1.6 bar but this quicky falls to 0.3 bar It is in the hands of a bloody good mapper so leak test & other standard tests have been done.
I'll be changing to a decent set of headers to see if these are causing the problem.
Has anyone else experienced a similar problem after fitting a new turbo or headers? Any suggestions?
Here are the details:
My 2.5 conversion was done over 12 months ago & the old turbo was holding boost fine. This weekend I fitted an MD321T and headers (which I skimped on via ebay).
Here's the problem:
It can boost up to 1.6 bar but this quicky falls to 0.3 bar It is in the hands of a bloody good mapper so leak test & other standard tests have been done.
I'll be changing to a decent set of headers to see if these are causing the problem.
Has anyone else experienced a similar problem after fitting a new turbo or headers? Any suggestions?
#5
Scooby Regular
Thread Starter
iTrader: (3)
Join Date: Dec 2005
Location: MY 98 STI 4
Posts: 490
Likes: 0
Received 0 Likes
on
0 Posts
I was thinking along the lines that the new headers & up-pipe weren't creating enough back pressure, whats your views on this?
#6
Scooby Regular
Join Date: Mar 2007
Location: The right side of 30psi
Posts: 539
Likes: 0
Received 0 Likes
on
0 Posts
Not really possible, you would hear it blowing quite bad for not to be spinning the turbo properly so fault is definately on the compressor side.
Trending Topics
#9
Scooby Regular
iTrader: (2)
Join Date: May 2000
Location: Class record holder at Pembrey Llandow Goodwood MIRA Hethel Blyton Curborough Lydden and Snetterton
Posts: 8,626
Likes: 0
Received 0 Likes
on
0 Posts
Interesting point, I was looking at the K+N filter covers that effectively make a cold air box with a feed (think they're called vortex or typhoon, something like that ) then the small print said good for 350hp. I've seen some of these filters on the CAK and some are tiny.
#10
Scooby Regular
Thread Starter
iTrader: (3)
Join Date: Dec 2005
Location: MY 98 STI 4
Posts: 490
Likes: 0
Received 0 Likes
on
0 Posts
& It's a Simtek
#11
Mike
#14
Former Sponsor
iTrader: (4)
Join Date: Jan 2001
Location: ECU Mapping - www.JollyGreenMonster.co.uk
Posts: 16,548
Likes: 0
Received 2 Likes
on
2 Posts
on a samco inlet pipe yes on a few turbo's
depends how bad it is (yours sound bad btw) - jubilee clips on the pipe as it has to expand oval when collapses and the jubilee on the outside re-enforces it.
a different inlet pipe
depends how bad it is (yours sound bad btw) - jubilee clips on the pipe as it has to expand oval when collapses and the jubilee on the outside re-enforces it.
a different inlet pipe
#16
Scooby Regular
Join Date: Nov 2006
Location: Enginetuner.co.uk Plymouth Dyno Dynamics RR Engine machining and building EcuTek SimTek mapping
Posts: 3,662
Likes: 0
Received 0 Likes
on
0 Posts
In actual fact, you're all correct, but for slightly different reasons!
We were mapping the car as a fait accompli, meaning we were doing a "tune what you brung"! We quickly realised that the turbo needed to be moved over to the centre from its arrival position, which was crushing the intake pipe big style. These always look a bit like that as it's very busy in there, and I've never been comfortable with the way it looks when they are in with some of these hybrids.
We moved the turbo another half inch over, and tried it again. We gained 50 bhp! but it still dropped boost over 5000 rpm, even at actuator pressure.
We have a number of other 2.5's in with our GT30 core turbo, and we don't get that issue. My feeling is it's down to the inlet port shape when the intake silicon hose is on. Our GT30 uses a larger inlet, and the slight kink to the intake hose doesn't cause an issue. We eventually removed the intake hose altogether, and the boost was then pukka all the way up.
We'd like to replace the ebay headers, and if anybody wants them you'll probably find them on ebay! The fitting of the MD321 with the small intake looks critical, and it makes me wonder how many others out there have the same issue. Dazza's uses the small intake as well, so I'm guessing he has Lateral headers, and a more centrally fitted turbo, proving they work just fine if these problems are sorted out!
We were mapping the car as a fait accompli, meaning we were doing a "tune what you brung"! We quickly realised that the turbo needed to be moved over to the centre from its arrival position, which was crushing the intake pipe big style. These always look a bit like that as it's very busy in there, and I've never been comfortable with the way it looks when they are in with some of these hybrids.
We moved the turbo another half inch over, and tried it again. We gained 50 bhp! but it still dropped boost over 5000 rpm, even at actuator pressure.
We have a number of other 2.5's in with our GT30 core turbo, and we don't get that issue. My feeling is it's down to the inlet port shape when the intake silicon hose is on. Our GT30 uses a larger inlet, and the slight kink to the intake hose doesn't cause an issue. We eventually removed the intake hose altogether, and the boost was then pukka all the way up.
We'd like to replace the ebay headers, and if anybody wants them you'll probably find them on ebay! The fitting of the MD321 with the small intake looks critical, and it makes me wonder how many others out there have the same issue. Dazza's uses the small intake as well, so I'm guessing he has Lateral headers, and a more centrally fitted turbo, proving they work just fine if these problems are sorted out!
#17
Scooby Regular
Thread Starter
iTrader: (3)
Join Date: Dec 2005
Location: MY 98 STI 4
Posts: 490
Likes: 0
Received 0 Likes
on
0 Posts
Hi Alan, thanks for that.
mmmm, I'd love the lateral headers & I have stacks of room on the paintwork for sponsor's details
I think the hard inlet pipe would cure the asthma, any thoughts about APS hard inlet pipes & how much are they?
mmmm, I'd love the lateral headers & I have stacks of room on the paintwork for sponsor's details
I think the hard inlet pipe would cure the asthma, any thoughts about APS hard inlet pipes & how much are they?
#19
Former Sponsor
Join Date: Jul 2005
Location: Wellingborough, Northamptonshire
Posts: 2,859
Likes: 0
Received 0 Likes
on
0 Posts
Worth pointing out the MD321 is available with a near standard size or larger 3" inlet. The poor inlet pipe is not the fault of the turbo!
In actual fact, you're all correct, but for slightly different reasons!
We were mapping the car as a fait accompli, meaning we were doing a "tune what you brung"! We quickly realised that the turbo needed to be moved over to the centre from its arrival position, which was crushing the intake pipe big style. These always look a bit like that as it's very busy in there, and I've never been comfortable with the way it looks when they are in with some of these hybrids.
We moved the turbo another half inch over, and tried it again. We gained 50 bhp! but it still dropped boost over 5000 rpm, even at actuator pressure.
We have a number of other 2.5's in with our GT30 core turbo, and we don't get that issue. My feeling is it's down to the inlet port shape when the intake silicon hose is on. Our GT30 uses a larger inlet, and the slight kink to the intake hose doesn't cause an issue. We eventually removed the intake hose altogether, and the boost was then pukka all the way up.
We'd like to replace the ebay headers, and if anybody wants them you'll probably find them on ebay! The fitting of the MD321 with the small intake looks critical, and it makes me wonder how many others out there have the same issue. Dazza's uses the small intake as well, so I'm guessing he has Lateral headers, and a more centrally fitted turbo, proving they work just fine if these problems are sorted out!
We were mapping the car as a fait accompli, meaning we were doing a "tune what you brung"! We quickly realised that the turbo needed to be moved over to the centre from its arrival position, which was crushing the intake pipe big style. These always look a bit like that as it's very busy in there, and I've never been comfortable with the way it looks when they are in with some of these hybrids.
We moved the turbo another half inch over, and tried it again. We gained 50 bhp! but it still dropped boost over 5000 rpm, even at actuator pressure.
We have a number of other 2.5's in with our GT30 core turbo, and we don't get that issue. My feeling is it's down to the inlet port shape when the intake silicon hose is on. Our GT30 uses a larger inlet, and the slight kink to the intake hose doesn't cause an issue. We eventually removed the intake hose altogether, and the boost was then pukka all the way up.
We'd like to replace the ebay headers, and if anybody wants them you'll probably find them on ebay! The fitting of the MD321 with the small intake looks critical, and it makes me wonder how many others out there have the same issue. Dazza's uses the small intake as well, so I'm guessing he has Lateral headers, and a more centrally fitted turbo, proving they work just fine if these problems are sorted out!
#23
Scooby Regular
Join Date: Nov 2006
Location: Enginetuner.co.uk Plymouth Dyno Dynamics RR Engine machining and building EcuTek SimTek mapping
Posts: 3,662
Likes: 0
Received 0 Likes
on
0 Posts
Like I said Paul, these are fine if sorted out! It isn't the intake hose that's at fault, or the turbo, so much as the tight bend just as it goes into the turbo. Even a little bit of a fitting issue has a dramatic effect on the boost. We think the headers on the car are contributing to the slightly offside bias to the turbo mounting, and we're going to fix it.
The interesting part is the fact that all these units have some degree of compromise, and the point at which it becomes a problem is marginal. Just that last little bit of restriction, and it appears to be game over. I'd say it isn't the size that's the problem, it's the shape, and the proximity.
Sponsorship? as we had thirty six cars at the last drag meet with my logos on, I think you know the answer to that one!
The interesting part is the fact that all these units have some degree of compromise, and the point at which it becomes a problem is marginal. Just that last little bit of restriction, and it appears to be game over. I'd say it isn't the size that's the problem, it's the shape, and the proximity.
Sponsorship? as we had thirty six cars at the last drag meet with my logos on, I think you know the answer to that one!
#24
Former Sponsor
iTrader: (20)
Join Date: Oct 2006
Location: 8.95 @ 168mph. Zero to 1KM 194.1mph
Posts: 1,150
Likes: 0
Received 0 Likes
on
0 Posts
Alan,
I suspect that if the up pipe positions the turbo 1/2" over from it's standard position, any turbo will be a struggle to fit, but I think the smaller intake would have given more room in this instance, with a 76mm intake being even more difficult to fit.
Mark.
I suspect that if the up pipe positions the turbo 1/2" over from it's standard position, any turbo will be a struggle to fit, but I think the smaller intake would have given more room in this instance, with a 76mm intake being even more difficult to fit.
Mark.
#26
Former Sponsor
iTrader: (4)
Join Date: Jan 2001
Location: ECU Mapping - www.JollyGreenMonster.co.uk
Posts: 16,548
Likes: 0
Received 2 Likes
on
2 Posts
larger inlet on my own md321t fits under a phase 1 inlet manifold with no spacers without issue..
the samco inlet pipe is notorious for sucking shut..
The position of the turbo will be effected by the bell housing bolt which needs removing as with any large turbo 20g size and up.
Simon
the samco inlet pipe is notorious for sucking shut..
The position of the turbo will be effected by the bell housing bolt which needs removing as with any large turbo 20g size and up.
Simon
#27
Scooby Regular
Thread Starter
iTrader: (3)
Join Date: Dec 2005
Location: MY 98 STI 4
Posts: 490
Likes: 0
Received 0 Likes
on
0 Posts
Which inlet pipe do you use? I don't think you can get APS hard inlet for this MY.
& I'm pretty sure that the bolt has been removed.
& I'm pretty sure that the bolt has been removed.
larger inlet on my own md321t fits under a phase 1 inlet manifold with no spacers without issue..
the samco inlet pipe is notorious for sucking shut..
The position of the turbo will be effected by the bell housing bolt which needs removing as with any large turbo 20g size and up.
Simon
the samco inlet pipe is notorious for sucking shut..
The position of the turbo will be effected by the bell housing bolt which needs removing as with any large turbo 20g size and up.
Simon
#28
Scooby Regular
Join Date: Nov 2006
Location: Enginetuner.co.uk Plymouth Dyno Dynamics RR Engine machining and building EcuTek SimTek mapping
Posts: 3,662
Likes: 0
Received 0 Likes
on
0 Posts
I'll report back on this one when we get the Lateral headers on, and sort out any other issues.
#29
Former Sponsor
iTrader: (4)
Join Date: Jan 2001
Location: ECU Mapping - www.JollyGreenMonster.co.uk
Posts: 16,548
Likes: 0
Received 2 Likes
on
2 Posts
Simon