the dreaded creep "dum dum duuuuum"

[Glanza D]

we all know what creep is what causes it and how we can fix it
ive read toby post about it and understand fully

i have a very unrestrictive exhaust the main reason for this is my nighpager decat with screamer blows a lil and my system (blueflame) is only rear muffler, so pretty much no restriction whatsoever
my question is...

if i whip my decat off and throw stock cat back on but gut it will it be noticably more restrictive then my decat ?

wastegate is ported as much as possible without needing a bigger penny.
air filter is a small MotoX style filter directly on side of tubby so no restriction there either.

anyway back to question will gutted cat be more restrictive or will i have to throw un-gutted cat back on untill i get it all sorted ?

 

[Paddy]

ive got a gutted cat, get the same amount of creep as with a zep racing decat i used to have

 

[Paddy]

try taping up half the air filter or putting the efi pipe back on or maybe even the air box

 

[ChrisGT]

Was gonna suggest tape up the air filter/standard air box, or some kind of restriction in the exhaust but you'll just lose performance in reality.

Seeing as you've ported the w/g to its full potential and fitted a standard CAT back in, I'd say you can only really go external to sort it out! What turbo is it out of interest ??

 

[durmz]

i hate boost creep ;( some people ave suggested to me getting everythng needed to run a bar to stop it creeping, and in effect, use the boost. get meh?

 

[Glanza D]

montanajr : its only stock ct9 not going external or wanting to pay out for owt expensive etc as its only to last me untill managment comes, nothing cheap aswell none of this emanage garbage, emerald K3

then td04 etc etc building up hence me not wanting to spend any money lol

may have to see what i can do about air filter throw a restriction in or something

any more ideas abotu stock cat guted etc

 

[Pav]

i hate boost creep ;( some people ave suggested to me getting everythng needed to run a bar to stop it creeping, and in effect, use the boost. get meh?

I get what you mean mate. When my standard ct9 was creeping I got a jam ecu to fuel the extra boost it was creeping too, but its not the ideal solution.

The best way is to stop the problem at its core, which is external wastegate or hybrid.

 

[dac69er]

you need to add restriction to reduce creep.

i would first try and restrict the inlet. mesh the filter with some really fine mesh to begin with. if that doesnt work then fit a restrictor plate in the exhaust. start with a hole 1/2" smaller than the bore of the exhaust and see what you get. you want to keep everything as free flowing as you possibly can without enducing creep. its all trial and error

 

[RobSR]

yup restrictor ring in the exhaust. and then raise the boost back up to what you want it to be with an EBC. its the classic way of sorting it out.

 

[Chris@CCM]

y not just port the w/g it will lower ur hp adding in restrictions

 

[ChrisGT]

y not just port the w/g it will lower ur hp adding in restrictions

He has mate!

 

[Adam_Glanza]

lol love the way some people really dont read the posts first!!!

best way is to put the stock inlet track but on or try and restrict the inlet.

tbh if your hitting fuel cut all the time your not getting to use the extra bit of power neway so there isnt much point

 

[Texx]

I find it rather strange that if I'm using V-Power or R-TC 102 ron fuel, I can keep the throttle wide open in 3rd gear until redline, but if I'm using regular super-unleaded I'll hit fuel cut in 3rd with wide open throttle by about 5200rpm. Both hitting the same boost level of 0.92bar.

I does make me wonder if the ECU cuts fuel based purely from the MAP/Boost reading, or whether the ECU also uses the knock reading to determine when manifold pressure is safe?

 

[Adam_Glanza]

its pretty simple texx, thats the exact reason why higher ron fuel is available..

the higher octane fuel you use the more air you can use safely.

the higher fuel uses up more oxygen when burning and makes a smoother ignition.

but lower fuel octane will require more air which will cause fuel cut easier

 

[Glanza D]

cheers all

all been very useful
rep added

im going to try to restrict inlet somehow 1st if that doesnt work its light right foot untill managment comes along

 

[Texx]

its pretty simple texx, thats the exact reason why higher ron fuel is available..

the higher octane fuel you use the more air you can use safely.

the higher fuel uses up more oxygen when burning and makes a smoother ignition.

but lower fuel octane will require more air which will cause fuel cut easier

I think you missed my point there.

I fully understand the make up of different fuels and the process of combustion.

My point is, if I see fuel cut with the same boost level at different RPM's depending purely on the RON rating of the fuel, then fuel cut must be calculated using not only manifold pressure, but also knock level. The ECU doesn't know I've just driven out of a Shell petrol station after filling with V-Power, it can only see lower levels of knock so it doesn't have to pull ignition timing back as far as it would with fuel that has a lower RON rating.

So it's possible that if I knock the base ignition timing back 2 or 3 degrees at the dizzy, it may lessen then chance of the ECU cutting fuel. Although this won't give me the maximum efficiency of the boost level I'm hitting, it may improve the 'anti-overtaking system' more commonly known as fuel-cut.