Lee Reynolds

As fitted to rsi/xr3i etc.

Am I right in thinking that after drilling the airbox for better airflow the mixure will be affected? As in weaker and will need richening to compensate?

cheers.

naturally aspirated

They used to advise against this type of home brewed mod on the old 2.8 Capri's.

Lee Reynolds

I have avoided it before mate but loads have said its a decent mod so thought I'd give it a go

capriturbo

I was told a similar thing, something about it changing the air flow so the flap moves irregularly at low engine speeds and causes dodgy idling. Not sure how much truth is in it though, I never bothered fiddling with it.

Alex

Lee Reynolds

Alex that is what put me off, I thought it must affect the vacuum control on the flap, but as said plenty seem to have done it! If I get no joy Ill revert back as I hate crappy idling!

capriturbo

"If it ain't broke don't fix it" lol there can't be much to gain from drilling it really though? Suppose if you have a spare box cant hurt to try.

vroooom ptssssh

Nah I dont thinkso mate, I've set cars up with the airbox off, stuck it on the RR, put the airbox back on it and no change. the flap moves relative to airflow and obviously whatever position that's in gives the correct amount of fuel if the metering unit is calibrated correctly to start.

Lee Reynolds

Are you sure your not on about turbo'd cars with KE jet there though Dave? Would be a mammoth task to set a RS1600i up without the airbox fitted!

vroooom ptssssh

Yea I'm talking about S1/S2's but same principle with the metering flap, no?

Done the same with an XR4i turbo, with K-jet!

Lee Reynolds

If your right dave I wonder why I cant get a decent idle on the car? And usually when you open the throttle screw it increases revs, but it is making it die - hence me thinking it was running lean and opening that screw to make it idle higher was making it leaner!

tabetha

As said flap moves relative to total air flow, as the pintle for the fuel is with the flap won't make a difference, adjusting the pintle will though as this adjusts it's position relative to the airflow/flap so increasing or decreasing fuel flow for the same given air flow.
tabetha

Lee Reynolds

Didnt quite follow that Tab, but I slightly richened her up half hour ago and she is running sweeeeeeeet Borrowing my mates analyser next week to check what CO Ive got now

vroooom ptssssh

The idle mixture screw is V.sensitive, sorted now though (hopefully) good stuff

Lee Reynolds

Yeah only gave it about 1 8th of a turn clockwise Dave

vroooom ptssssh

That's still quite a lot in terms of adjustment, but it could well be that it needed it! best just to see what the gas anyliser sais, makesure it's as far into the tailpipe as you can get it