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FK8 Booooost!

S

str6mik

Messages
194
Whilst in between watching out for pedestrians and other road related nuisances I’ve been following the boost display with vigour

Whilst I understand there is a balance between high revving / compression ratios and boost I’m surprised just how punchy the boost is low revs ( less than 4K) boosting around 1.6-1.7 but then boosting at about 1.2 after

My previous Megane was mapped but that pulled all the way on 1.3 bar boost from low revs to high

Would love for someone with a keener engineering mind than mind to give a view as to whether there is some more gains to be had if the compression / block could support it - specifically in terms of the boost relationship observable
 
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Of course there will be some gains to be made, no engine comes to the factory running max power, it wouldn't go well for the warranty/reliability
 
I too would be interested to know how boost is managed. Does it have "overboost" for a short period? Does it operate on mass air flow and vary boost to meet the required air flow figures?

I have noticed up to 1.6bar according to the dash display and it seems to hold this rather than just be an "overboost" sceneario. Other times same gear/day it doesn't boost as high but performance feels similar. Higher gears (4/5/6) seem to generally hold less boost which is odd as I thought it might be the other way around with boost limited in lower gears. I haven't noticed boost levels changing with air temp but haven't done any specific testing. I guess you would need to read the ecu figures for accurate monitoring as the dash may be inaccurate.

Who makes the ECU? Honda or someone like bosch?
 
Ruxpin said:
I too would be interested to know how boost is managed. Does it have "overboost" for a short period? Does it operate on mass air flow and vary boost to meet the required air flow figures?

I have noticed up to 1.6bar according to the dash display and it seems to hold this rather than just be an "overboost" sceneario. Other times same gear/day it doesn't boost as high but performance feels similar. Higher gears (4/5/6) seem to generally hold less boost which is odd as I thought it might be the other way around with boost limited in lower gears. I haven't noticed boost levels changing with air temp but haven't done any specific testing. I guess you would need to read the ecu figures for accurate monitoring as the dash may be inaccurate.

Who makes the ECU? Honda or someone like bosch?
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Glad it’s not just me then that was thinking these elements.

I too was wondering whether it was an over boost function - but it seems to lose boost after about 4 k - which I assumed given the compression it couldn’t hold.

I would have expected the boost to be limited in the lower gears / low revs to manage traction but it seems to be the other way round. Seems to boost at 1.6bar at low revs and leave it to the traction to manage. My meg was the total opposite low boost low down and max all the way from 3krpm

I find the mapping of the car very interesting!
 
I could be wrong but I imagine this is Honda wanting to make the car a bit more like vtec's of old. It is a pretty revvy engine for a turbo.
 
VTECMattC said:
I could be wrong but I imagine this is Honda wanting to make the car a bit more like vtec's of old. It is a pretty revvy engine for a turbo.
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I agree, its definitely very revy compared to other turbo cars I've had and really reminds me if my old ep3 with the exhaust and engine noise zing at the top end
 
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