I have just had a straight through exhaust system fitted and decatted but since then when changing gears i sometimes get a POP/Backfire which sounds kinda nice, any idea's?

 

its the fact there is less in the system to restrict gas/unspent fuel


nothing wrong with it

 

get it REALLY hot and you should get a few flames coming out

 

Its unburnt fuel igniting in the exhaust........,dont have a vta fitted do you by chance?

 

LOL at the flames hehe but whats a VTA?

 

Vent To Atmosphere dump valve.

Can upset fueling and may add to your pops and bangs

 

Ah that may explain a few things it has a great big red noisy dumpvalve that getting on my nerves, and i only get 175miles to the tanke when taking it easy and 150 when playing

 

What sort of driving is that town, mixed, motorway? Mine varies greatly dependant on what roads im on and how much im nailing the throttle down , You can get 300 out of a tank if you take it to 70 ish on a motorway.

 

Usually get 202 to 3/4 tank in mine. mixed driving.

 

nah thats mixed driving getting 175mile but mines an import do they have a smaller tank or something, but its time to lose the stupid dump valve i thinks

 

Have you had the car remapped after fitting a de-cat?

 

175 miles is really bad. My Type-R was averaging 100 more than that.
What model / spec is it?

Nick

 

i've a my98 type r and am only getting just over 200 to a tank
thats taking it easy too

 

175 is bad? good god im in trouble then looool

 

I work away from home which is about 230 miles and I use 3/4 of a tank. And thats sticking at about 75. I've been told If I replace my first cat from exhaust I will have to chip the car. Which will cost me 500 quid.

 

No i haven't had the car remapped do i need to?
the car is a 96 WRX import

 

To get the most out of the modification you should do.

The fueling will be out due to the change which will account for some of the popping.

I had the same on mine, when it was remapped the popping stopped.

 

the jap ones have to be mapped because of increased detting issues??? but the uk ones can be fine i think? can anyone shed some light on this.

 

No no no! The import cars do ot 'HAVE' to be mapped when you have a decat installed. Just get the fueling checked.

 

coool!!!

does this apply to the uk ones aswell? mine is fully decatted, i suppose i dont "have" to get remapped, r there any dangers?

 

i love this thread. reading this just makes it harder to wait lol.save me having to get the "backfire system oogy" installed

 

Well you don't HAVE to get it mapped but i would have thought it is more than advisable. It won't be fueling right and with the newage i know a lack of cats gives a risk of boost spikes and turbo melting action. Not sure if it is the same with the older cars but i suspect it is. That's increased risk mind, not saying it definately will go wrong, the choice is yours!

5t.

 

k mine must be real bad then i thought it was normal 120-130 miles mixd drivnfull tank wot could be wrong here ??

 

oh yea the car is a 98 sti ra with a few mods should it still be doing more??

 

Mine is a my99 Type-r decatted & 3" zorst NOT Remaped, around town thrashing and motorway thrashing about 200 miles to 50 litres of fuel

Motorway driving off boost 250-300 miles

Remember the Type-r has a very low ratio box, so revs higher thn most cars.

 

my uk turbo used to pop and bang after changing gear,i spoke to interpro in bristol about it and they said it was my definately my atmospheric dump valve causing it.according to them its not a problem and WONT cause any damage i have now just bought an import sti.i tried an atmospheric dump valve on it the other day and it did cause it to start poppin aggain.personally i love my car soundin like a rally beast

 

They do make you over fuel, and can cause dammage from what iv read.

 

I use to get loads of pops and bangs on my MY00 with a full decat and a HKS SSQV.

After Bob Rawle worked his magic on my motor, I lost the pops and bangs but gained lots of power

 

If you have a MY96 you will also have a self mapping ecu. This is locked and canot me mapped. Cars under 98 have locked ecu's unless a new one has been fitted. Why would you want to lose the pops and the bangs? You drive a scooby and you will get looks everywhere you go and you know deep down that you love it pop's bangs and flames just make it better. as for your mileage i would get someone to have a look at it and if it is an import i would also make sure you are useing the correct fuel as this can cause you an even bigger problem. I have a full decat on my 94 classic wagon and it flames,who gives a s**t about the miles per tank when you smile all the way

Iain

 

WELL SAID Iain