markpm

Hi all,

Just had a TSL Firestorm backbox fitted to my otherwise OEM system, and although it sounds good, Im getting popped to death when changing down gears, even at slow speeds and when engine is cold.
Car is a 99 Type RA V-Limited.
Im now worried that the engine is running far more rich than it should be.
I know Scoobs are 'supposed' to run rich, but how much exhaust popping is normal?
I always run Super Unleaded and a whole bottle of Millers OB per tankful.
And is there an easy way to check if the engine is running too rich? (bearing in mind Im not very mechanically minded!)

Cheers
Mark...

Trout

iTrader: (1)

With a more open exhaust you will get more pops and bangs - you just couldn't hear them with a quieter exhaust.

Even with my HKS - putting the bung in made the pops and bangs go away.

In terms of running rich - they are not supposed to run rich - mapped correctly they should run just where they need to - with a peak power CO ratio of around 7.5-8% for ideal power.

As it is a MY99 you might want to consider an ECUTEK remap to optimise it to UK fuel.

Rannoch

StickyMicky

they are mapped slightly rich tho?

markpm

Hmmmm, thanks for the replies.

Is there any way to tell if Im running too rich (without gauges etc) or not?
Would it also be wrong to say that since the box has been fitted, I seem to have lost a bit of power, rather than gained it?

Just seems like I have to boot it more than I did to get the turbo to spool up.
Im sure it used to spin up at about 2500 rpm, but now its more like 3500 rpm...
Is this to do with losing some back pressure with the larger bore exhaust?

Trout

iTrader: (1)

Lower down there may be some loss - but at the top end it should flow much more freely.

Sticky....what is mapped a little rich - certainly the JECS ECU MAP is rich in some places and lean in others. My MY99 Sti was rich all over the place except where it counted - a little lean around 7,000rpm which is the last place you need it - especially with 97RON fuel! Det was an occasional visitor!