setting a carb with sniffer

[djinuk]

Ok, plan is simple, over the next week im going to fit a carb rebuild kit aswell as a new filter onto my r5, and take it for mot, my mixture may need adjusting on mot, and markey mark told me the easiest thing to do is set it when it on the sniffer.

Now i know a good base point is 2 and a half turns out on the mixture, however on the sniffer what kind of co reading should i be looking to aim for, and what idle rpm.

just to add , car is standard with t2 turbo, standard boost, and standard jets.

[Scoff]

1.5% co is the limit (unles the law has changed recently ?). 0.5-1% is fine.

[djinuk]

ah didnt realise it was that low, my pug was fine anywhere below 3% lol, but sweet, so anywhere between 0.5 and 1% is ok for mot, aswell as preventing it running lean during boost. I am just so worried now about all the talk of making sure the car is fueling correctly otherwise pop goes the headgasket. :P

[Sy5GTT]

I don't think the idle co2 has alot to do with on boost afr. I may be wrong though. :confused:Scoff or someone will know.

[Chris Hebden]

Pre 1992 i think it is your allowed upto 3.5% and 1200ppm? After this date your into cat terratory and that is when you are only allowed anymore than 1.5% i think it is.

AS Sy has pointed out its ok to set up idle like this but wont help when the boost kicks in, is it a running carb thats already been set up for the boost you have/want to achieve?

[djinuk]

nope, all i know is the carb is using standard jets, and the boost i believe should be set to standard as it is., ive been reading up more and im guessing the on off boost mixture is all determined on what jets are currently situated within the carb, meaning so long as my boost is standard, and my jets are standard, then it should all be fine.

Sorry im young, and carbs confuse hells outa me, but ill learn it if it kills me.

[Sy5GTT]

If your using the Turbo and actuator you got off of me you may need to lengthen the rod as I think it was running 14psi.

[djinuk]

ah yes i am using that , sorry forgot i actually brought it off yourself. Ill sort that then. What additional would i need to run at 14psi safely?

Do you know the rough length of the actuator rod to run standard boost.

[Sy5GTT]

You may be ok with standard jets but I would check with a wideband/rolling road just to be safe. Possible drill the 2nd stage out to 1.2mm? Again Scoff or someone like that will know more than me.

[Chris Hebden]

I thought 14psi was the max you could run on standard jets? Read the carb article, great read to give you a good start and an in depth understanding into the 5 carbs!

http://www.rtoc.org/boards/showthread.php?t=460

[djinuk]

yea just had a long read of that article, i was always under the impression that the mixture screw made changes throughout the revs you see, now i am aware it is all down to the jets to adjust the fueling on boost etc. I think i am going to shorten the actuator for the time being and leave the jets as standard.

[Sy5GTT]

Make the rod longer to decrease boost.

[djinuk]

Make the rod longer to decrease boost.

that rather, , very tired :P