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Discussion Starter · #1 ·
Hi Guys,

So after hearing about the LSPI issues the Mk3 cars suffer with I've been a bit watchful of the boost gauge and have noticed the car does use a bit of boost (up to half a bar) occasionally in the 5th and 6th gears even when just prodding the throttle on the motorway to overtake. When I say prodding I literally am only gently pressing the throttle slightly (in the least aggressive way possible) to get past the odd lane hogger. I was quite surprised to see this as I only assumed the car would engage boost under more aggressive acceleration past around 2.5k revs which it's sitting below just cruising on the motorway. Is this sort of thing harmful to the engine? Or is it instances of just stomping on the pedal in 5th and 6th gear getting max torque in low revs? The car isn't mapped or anything as far as I know.
 

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Mike Mk2 ST225
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I'm not sure what exactly the MK3 does guage wise, but that eagerness to go is exactly why people love the car, and what can cause the issues.

But if you're only gently applying the throttle you shouldn't really have anything to worry about, it's asking for max power at low rpm that causes the issue with "some" cars as the piston is essentially being forced to contain the explosion instead of moving with it, combined with the chance of knock that causes weak pistons to shatter. As I understand it.
 

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Discussion Starter · #3 ·
I'm not sure what exactly the MK3 does guage wise, but that eagerness to go is exactly why people love the car, and what can cause the issues.

But if you're only gently applying the throttle you shouldn't really have anything to worry about, it's asking for max power at low rpm that causes the issue with "some" cars as the piston is essentially being forced to contain the explosion instead of moving with it, combined with the chance of knock that causes weak pistons to shatter. As I understand it.
Ah okay this makes sense, was just a bit surprised to see any boost at all in low revs with very little throttle application.
 

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Mike Mk2 ST225
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My mapped mk2 decides to boost if I even think about touching the throttle at motorway speeds so definitely wouldn't worry too much about that
 

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Formerly Azionamento
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So basically pressing on the accelerator at motorway speeds isn't going to do any harm on the MK3 whereas pressing down hard at low rpm (less than 2k) is pointless and it might cause some 'knock' problems and the lack of oil pressure might also be an issue. I'm not an engine expert but remember the ST is a Focus...and just a Focus that's designed to be sold worldwide and cope with all sorts of driving styles without damage or problems. I wouldn't worry.
 

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Thanks to all,
I've recently had a remap done on my Mk3, and have also noticed that when cruising in 5th/6th gear, and applying gentle pressure to throttle it's asking for boost, I was a bit concerned about the whole lspi issue,
I guess then, that as long as I'm not mashing the throttle in high gears, a bit of boost is nothing to be concerned about, and no harm in dropping a cog or two, just to be safe,
Advice appreciated, hate to destroy the best car I've ever owned,
 

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Discussion Starter · #7 ·
Thanks to all,
I've recently had a remap done on my Mk3, and have also noticed that when cruising in 5th/6th gear, and applying gentle pressure to throttle it's asking for boost, I was a bit concerned about the whole lspi issue,
I guess then, that as long as I'm not mashing the throttle in high gears, a bit of boost is nothing to be concerned about, and no harm in dropping a cog or two, just to be safe,
Advice appreciated, hate to destroy the best car I've ever owned,
I think it should be okay as long as you're not stomping on the pedal at low revs, which remap did you go with out of curiosity?
 

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I think it should be okay as long as you're not stomping on the pedal at low revs, which remap did you go with out of curiosity?
Company called "Top Gear Tuning" set up by the original TG Stig, Perry Mccarthy, but as of today, they have no affiliation, process was really easy, and the map has been excellent so far, even seen an increase in mpg, only a few miles, but any increase is better, looking at stage 2 later, but will be upgrading i/c first,
 

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The IC on the MK3 ST is good for over 300bhp I would be more worried about exhaust gas temps.
Thanks Jason,
Stage 2 with Top Gear is 290 bhp and 450 nm, have no plans to go above 300bhp, assume the clutch will cope also
What's the best course of action regarding exhaust gas temps
Thanks
 

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Jason SB MK3 RS
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Thanks Jason,
Stage 2 with Top Gear is 290 bhp and 450 nm, have no plans to go above 300bhp, assume the clutch will cope also
What's the best course of action regarding exhaust gas temps
Thanks
The IC on the MK3 is the one off the MK2 RS so is def good for just over 300bhp.

Not aware of any problems with the std clutch.

Because the manifold is cast into the head it gets hot and only way to cure that would be a downpipe and sportscat.
 

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The IC on the MK3 is the one off the MK2 RS so is def good for just over 300bhp.

Not aware of any problems with the std clutch.

Because the manifold is cast into the head it gets hot and only way to cure that would be a downpipe and sportscat.
Thanks again Jason
Really great advice, that's the way I'll be going
Cheers
 

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Focus ST 250 MK3.5
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Just had my mk3 mapped by map kings who have taken over superchips, if i floor it in 6th, at around 80 the turbo gauge nearly
Hits the red.until it gets upto around 130mph then it slowly drops off. Bit worried.
Never had a turbo before so not sure what I should be looking out for.
Ps I ran those speeds on my friends land not on the uk roads
 
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