rich afr's

[R5MJH]

right been to garage today in this crap weather to do bits on mikes car, done tappets, got old rad rethreaded on oil way, fitted and the heating problem on boost is sorted, also checked turbo no play at all and replaced alot of blue water pipes, changed carb for the one i totally rebuilt, put all back together but the afrs are crap, the carb runs sweet but on tick over im getting 13.9, soon as i rev it goes to 10.9 and on boost about the same, i cant boot to much as i notice the oil return is fubar today

120 main
1.0 ac
1.4 2nd

any help always appreciated no air leaks, all new gaskets may have to put on carb back on and drill 2nd stage as all the afrs were great not sure helpppppp thanx mick
edit also if i turned mixture screw would this help ive sealanted it but can remove it

[SCHWARTZ]

A little turn in would help the idle afr's. Does the carb function properly? Ie fuel not dribbling out the emulsfier tube acc pump adjusted with a 5mm drill bit etc...?

[Brigsy]

Mixture screw wont make any difference to on boost fuelling mate. Its probably due to 1.4 2nd stage, you will need to run a fair whack of boost to lean it off

[R5MJH]

A little turn in would help the idle afr's. Does the carb function properly? Ie fuel not dribbling out the emulsfier tube acc pump adjusted with a 5mm drill bit etc...?

nope none of this gaz i understand where ya coming from brigsy but the cars only running 14 psi at mo and i cant push to hard as oil return is fubar mate might just drill 2nd on the other carb this setup was

120 main
0.9 ac
1.2 2nd stage

but at 14psi @wot we we getting 12.4

tick over was 14.5/14.8
cruise was good too

[car.crash]

The issue on boost is your second stage. 1.4 is to big for 14psi.
I was 1.3 at 20 psi and still rich.

[R5MJH]

that would make it more richer gaz??

[SCHWARTZ]

Yeah swap it back, or rebuild that one as well then swap it

[R5MJH]

The issue on boost is your second stage. 1.4 is to big for 14psi.
I was 1.3 at 20 psi and still rich.

thanx mate was hoping to be running 20 ish soon it wont harm the turbo running a tiny bit rich will it?

[Logg]

As other have said id expect that carb for a gtt running around 200bhp.

Mike sort the oil leak and slowly up the boost one night until afr's are are around 11.7-12.0 obviously the leaner you are the braver/more confident you are in your set up. Ie act, ignition timing, cam timing and egt's

[casper]

Mines
1.0mm a/c
120 main
1.25 2nd stage
20psi
177hp
afrs@wot are 11.

[R5MJH]

As other have said id expect that carb for a gtt running around 200bhp.

Mike sort the oil leak and slowly up the boost one night until afr's are are around 11.7-12.0 obviously the leaner you are the braver/more confident you are in your set up. Ie act, ignition timing, cam timing and egt's

thanx logg so if its running rich all over this wont fubar anything only the plugs just ordered return so thats the next job, im confident about the cam timing etc but this threw me abit, maybe 1.4 is to much, maybe 1.3 would sufice, got got two other bodies on 1.2

[R5MJH]

Mines
1.0mm a/c
120 main
1.25 2nd stage
20psi
177hp

afrs mate

[casper]

11@wot.

[Logg]

thanx logg so if is running rich all over this wont fubar anything only the plugs just ordered return so thats the next job, im confident about the cam timing etc but this threw me abit, maybe 1.4 is to much, maybe 1.3 would sufice, got got two other bodies on 1.2

How long you planning to run it like this? What you afr you got while cruising?

Casper the higher the number the leaner it is. My 2p on what fueling should be.

14.5-15.0 at idle

14- as lean as you can get it with out hesitation off boost

11.5 12.2 on boost depending your set up.

And dont push much more than 20psi on oe pistons unless your happy playing russian roulette with your ring lands.

[R5MJH]

How long you planning to run it like this? What you afr you got while cruising?

Casper the higher the number the leaner it is. My 2p on what fueling should be.

14.5-15.0 at idle

14- as lean as you can get it with out hesitation off boost

11.5 12.2 on boost depending your set up.

And dont push much more than 20psi on oe pistons unless your happy playing russian roulette with your ring lands.

afr tick over 13.9 ish
cruise 10.9/11 ish
wot not 100% as oil return

if its going to be ok to run like this for 20 psi then no probs, my tungy ran 25psi on oe perfect circles no probs but i know what ya mean logg
whats your recommendation mate

[Logg]

afr tick over 13.9 ish
cruise 10.9/11 ish
wot not 100% as oil return

if its going to be ok to run like this for 20 psi then no probs, my tungy ran 25psi on oe perfect circles no probs but i know what ya mean logg
whats your recommendation mate

Sounds a little rich a cruise wish I could tell you how to change that as I was lucky and had 15'at cruise on my carb so never had to fiddle with off boost fueling.

Yep much more than 20psi and you cant be upset if it craps itself which I might push later this year since ive done 2k at 24 so far.

[casper]

Yeah I'm familiar with afrs now and am happy running@11 wot on my set up.
Idle is 14.1 ish
cruising 14 Ish
part throttle 12s.
Not really sure if the 11@wot is wasted fuel or a little bit of extra safety.Hopefully the latter.

[SCHWARTZ]

11's @ wot is prob wasting fuel and sapping power.

[casper]

11's @ wot is prob wasting fuel and sapping power.

Not bothered about the loss of power.

[R5MJH]

Sounds a little rich a cruise wish I could tell you how to change that as I was lucky and had 15'at cruise on my carb so never had to fiddle with off boost fueling.

Yep much more than 20psi and you cant be upset if it craps itself which I might push later this year since ive done 2k at 24 so far.

good man the other carb i took off was sweet 14.5 idle, same on cruise ish and wot 12.4@14psi think ill put old carb on and drill 2nd to 1.3

this had 120 main, 0.9 ac, 1.2 2nd stage

you got to love it when it craps itself mate, good thing with mikes is everything is new lol

[Dave Reed]

Have you checked to make sure that the acc pump is adjusted correctly mike?

Should'nt really be dropping that low on cruising..

[Brigsy]

How long you planning to run it like this? What you afr you got while cruising?

Casper the higher the number the leaner it is. My 2p on what fueling should be.

14.5-15.0 at idle

14- as lean as you can get it with out hesitation off boost

11.5 12.2 on boost depending your set up.

And dont push much more than 20psi on oe pistons unless your happy playing russian roulette with your ring lands.

Whoa who said the stock piston ringlands fail at 20lbs? Ive ran over that for years and many others have. I ran 26lbs for ages standard comp, saying that there was no det and afr's of high 11's. I seen 7000rpm + in 5th a fair few times at this boost.

[R5MJH]

Have you checked to make sure that the acc pump is adjusted correctly mike?

Should'nt really be dropping that low on cruising..

thanx dave yep did all that when i rebuilt it tbh these are the figures we were getting on the 140 main which we have soldered now to 120 i dont understand all i know is the carb i took off was sweet the spec now is the exact same apart from the 2nd stage being bigger which is for when boosting

[R5MJH]

Whoa who said the stock piston ringlands fail at 20lbs? Ive ran over that for years and many others have. I ran 26lbs for ages standard comp, saying that there was no det and afr's of high 11's. I seen 7000rpm + in 5th a fair few times at this boost.

thats what i said my tungy ran 25 daily on perfect circle oe mate

[Logg]

Whoa who said the stock piston ringlands fail at 20lbs? Ive ran over that for years and many others have. I ran 26lbs for ages standard comp, saying that there was no det and afr's of high 11's. I seen 7000rpm + in 5th a fair few times at this boost.

Your not the only one lol four and a half years of doing at least 3 1/2 thousand miles a year. At varying boost between 15-25psi most of it at 20+.

But I would never advise someone to run more much more 20psi until knowing there knowledge level and them knowing it could end in tears. There are far more people with failed engines at 22psi + than around 20.

[R5MJH]

heres the old tungy i refer too

[R5MJH]

There are far more people with failed engines at 22psi + than around 20.

i do agree with that mate

[R5MJH]

put the old carb back on today, while i did some other things for sangliers and alls fine, so im not sure whats up with the carb totally rebuilt, the specs on this carb are 120 main
0.9 ac
1.2 2nd

afr idle 14/15
cruise high 13/14
wot not sure as not booted yet

thought id let ya know