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I was told the boost would go up a few psi with new dump because theres less restriction at the turbo outlet, hence it spins faster n quicker, therefore more boost, so retune?? Have seen most threads where peopke just do the dump but no retune..

I was told the boost would go up a few psi with new dump because theres less restriction at the turbo outlet, hence it spins faster n quicker, therefore more boost, so retune?? Have seen most threads where peopke just do the dump but no retune..

Id consider an EBC to reduce the boost back to stock until you tune your car. Sudden spikes in psi might destroy your stock turbo.

I chucked on a hks split dump and 3 inch front pipe a couple off weeks ago and it changed my tune significantly. The car was happy to have a tiny bit more timing, was leaner in the first 5 load cells, was a lot richer in the midrange and leaned out up top. Needless to say I fixed it. I'm tuning my power fc with a wideband and datalogit btw. The boost level didn't change after the pipe swap.

Thanks for the reply so i guess a bigger dump WILL mess up with the afrs thus screwing up the tune, pretty annoying that u cant add things bit by bit without changing the tune, what about pple who change their full exhausts from stock i never hear of them havin a retune, exhaust is usually always the first of mods and most guys at this stage dont have an ecu to tune.. In my case i have the full exhaust n tuned ecu already, just need a 3" bellmouth dump that i dont have.

it would only alter the tune slightly, that is, use different cells

so depending on how your car is tuned, you might not need a "retune"

if its tuned properly, most tuners extrapolate the values to the neighbourhood cells on the map (ie the right way) so its fine if it varies a little

after all

air temp

air pressure

humidity

fuel quality

octane rating

these vary every minute of the date and you dont need to "retune" each second

so its prefectly fine and it might be ok, so don't "panic" but it is a good idea to check the AFRs on a dyno

but dont get sucked in if workshops "DEMAND" you must retune from scratch for a simple dump pipe

Just check it but like Paul said don't pay for a tune from scratch. It took me and the missus about 20 min of driving to fix mine.

No tuner would tune it from scratch anyway, they would just tidy up the existing tune, probably 30 minutes work max to confirm everything is in check.

If they say they are tuning it from scratch they are taking you for a ride as it makes no sense to wipe a tune and redo it, just a waste of time for no reason. They would most likely just touch it up and charge you more for the sake of it, I hope there are no tuners around that would do this though.

Edited by Rolls

That is why i dont take it to workshops, not only that, i know a fair bit of stuff myself so nobody can really take me for a ride, and still learning from all yous awesome peeps on sau...this website is great thanks to ya all

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