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Old Jul 10, 2018 | 07:16 PM
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Default Launch control question

Hi people i need some advice i have a Subaru sti 2004
I have had a fully forged engine built few months back, new turbo ect
I have had it mapped fully by duncan graham. Anyway i took it to santa pod on rwya and when on the start line i put clutch down and foot on the throttle and car would rev up to roughtly 4k which is were the launch control is set. But the turbo was not spooling up fully so the car would bog down on the line. To have this adjusted so launch control is set with the turbo spooled up do i have to go back to the mapper, its fitted with a simtek/alkatek Ecu. Cheers in advance 👍
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Old Jul 10, 2018 | 08:27 PM
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Originally Posted by dooby-do
Hi people i need some advice i have a Subaru sti 2004
I have had a fully forged engine built few months back, new turbo ect
I have had it mapped fully by duncan graham. Anyway i took it to santa pod on rwya and when on the start line i put clutch down and foot on the throttle and car would rev up to roughtly 4k which is were the launch control is set. But the turbo was not spooling up fully so the car would bog down on the line. To have this adjusted so launch control is set with the turbo spooled up do i have to go back to the mapper, its fitted with a simtek/alkatek Ecu. Cheers in advance 👍
If u had a stock ecu with carberry you could DIY with a tactrix cable

Not too sure how Alkatec works.

It would annoy me paying all that money for an Ecu i couldnt access myself.
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Old Jul 10, 2018 | 09:25 PM
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4000rpm does seem borderline for LC.
I'd speak to Duncan, perhaps he could call on his way up to RCM, if it's just a quick re-set.
Trev
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Old Jul 10, 2018 | 09:51 PM
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If on a bigger turbo sc42 ish id want it at least 5

How much boost you making on the line. Try letting it build a little
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Old Jul 10, 2018 | 10:42 PM
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Im running a fp red it made 531hp on the rollers, the previous turbo was a md321
So it would have spooled up quicker. And the launch control and anti lag was set up with the old turbo. I have dropped dunchan a message so will have to wait for a reply, i did 5 runs and tryed to let it build boost every time but kept bogging down quickest i managed was a 11.6 but again slow on take of
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Old Jul 10, 2018 | 11:20 PM
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Originally Posted by dooby-do
Im running a fp red it made 531hp on the rollers, the previous turbo was a md321
So it would have spooled up quicker. And the launch control and anti lag was set up with the old turbo. I have dropped dunchan a message so will have to wait for a reply, i did 5 runs and tryed to let it build boost every time but kept bogging down quickest i managed was a 11.6 but again slow on take of
why weren't they adjusted when it was mapped for the new turbo?
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Old Jul 11, 2018 | 06:33 AM
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Originally Posted by dooby-do
Im running a fp red it made 531hp on the rollers, the previous turbo was a md321
So it would have spooled up quicker. And the launch control and anti lag was set up with the old turbo. I have dropped dunchan a message so will have to wait for a reply, i did 5 runs and tryed to let it build boost every time but kept bogging down quickest i managed was a 11.6 but again slow on take of

im also running a FP red @ 531bhp ,, mine seems ok with a 4k launch and is set at about 1bar (I think) ,,, good thing about the hatchback is I can ajust my launch on the fly with my cruise control buttons but so far I haven't had to

Last edited by domino46; Jul 11, 2018 at 07:25 AM.
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Old Jul 11, 2018 | 12:29 PM
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I have no idea why it wasnt set when it was mapped it was first mapped at surrey but there was a issue with the exhaust so had that changed and took it to rcm as it was closer and mapped again but the anti lag and launch control wasnt set, i have messaged duncan via text and his website but no reply as of yet
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Old Jul 11, 2018 | 09:07 PM
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I'd doubt it was a mapping problem and more to do with heat soak.
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Old Jul 12, 2018 | 08:36 AM
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Originally Posted by Buzzer2017
I'd doubt it was a mapping problem and more to do with heat soak.
larger turbo will need more revs, heat soaks had nothing to do with it. Also larger turbo will need more fuel because of airflow
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Old Jul 12, 2018 | 08:58 AM
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How much boost was it actually making on the line tho ?

Also depends if its fuel cut or spark cut,

For example my Carberry map can build over 1 bar around 5krpm

Ecutek struggles to make half that so requires another 750-1000rpms

The carberry does better 60ft times due to it being on boost as it comes off the line.

I tried spark cut in my daily bugeye sti and it is savage AF
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Old Jul 12, 2018 | 09:36 AM
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Originally Posted by SmurfyBhoy
How much boost was it actually making on the line tho ?

Also depends if its fuel cut or spark cut,

For example my Carberry map can build over 1 bar around 5krpm

Ecutek struggles to make half that so requires another 750-1000rpms

The carberry does better 60ft times due to it being on boost as it comes off the line.

I tried spark cut in my daily bugeye sti and it is savage AF
a bigger turbo may well be making less at that point becuase it takes more input to get a higher output, aka lag

thast why it needs setting up

as far as spark cut, good way to blow an engine that.
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Old Jul 12, 2018 | 06:01 PM
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It was extremly hot on the day 30+ outside but even when i let it cool down a bit before going again was same issue, i have now spoken to duncan and he has said it will just need revs upping on the launch control so fingers crossed it sorts the issue
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Old Jul 12, 2018 | 06:25 PM
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Originally Posted by Tidgy
a bigger turbo may well be making less at that point becuase it takes more input to get a higher output, aka lag

thast why it needs setting up

as far as spark cut, good way to blow an engine that.
Spark cut makes the heart work.

Also it's what the big boys like to play with.

If your scared of a little gasket trouble then yea prob best avoid it

Also dont confuse "Lag" with "Boost Threshold"
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