Help setting up Afr

[bigdavec1974]

Hi all, having had the latest 5 for over 2 years it's almost time to set her up!!
Does anyone know of anyone capable of setting the fueling up for 18psi in or around Essex.
I don't just want to as previously , 130 main jet and swap the first stage with the a/c jet.
I have an Afr gauge fitted in car as well as a hand held Lm-2. To be honest it doesn't feel too far off :/
Cheers

[Alex]

What AFR's are you getting at the moment? To be honest theres not many people that set up GTT's anymore, your best bet would be doing it yourself or maybe ask a local member/rep. :)

[bigdavec1974]

Hi mate,
Idles at 14.5 , cruises at around 13.5 wot at around 12.2 bit worried though seemed to misfire or det at about 110 wot on a private road ofc haha.
I am 180 out though, could it be that?

[Alex]

Is it still fuelling o.k. when you're flat out in 4th/5th gear? 12.2 is o.k. The carb bowl can start to empty when you're in the higher gears.

Plugs/leads/dizzy cap o.k.? I take it you've swapped the leads over if it's 180 degress out? If so that's o.k.

[bigdavec1974]

Hiya,
Ye the leads have just been reversed but didn't know if could cause issues at high revs?
Best way to stop the bowl emptying is a larger venturi?
Tbh didn't notice any leaning off but it's kinda hard and drive at the same time lol

[Alex]

Just keep an eye on the AFR gauge, it'll creep up if it starts emptying.

[bigdavec1974]

Bit of an update.
Seems the Afrs are fine until about 80-90 mph then climb from 12.2-17.0 within 0.5 secs.
The car is really hard to start after sitting for more than a few days kinda like the fuel lines and carb are empty. Fpr, pump or just needs rejetting?
Weird.
It's my 3rd r5 get turbo, owned one since 1996, never had a problem like this before :(

Helps please haha

Thx

[rs250nut]

Do you still have the anti perc fan?

[bigdavec1974]

Ye I do , works fine :(

[Alex]

Sounds like the carb bowl is emptying to me. Check your fuel pressure, it should be about 4psi above boost level i.e. on idle it should be 4 psi and at 18 psi boost it should be about 24 psi fuel pressure. If that checks out you might need a bigger needle jet/adjustable FPR. I wouldn't have thought you'd need one for that amount of boost though.....

[Matt Cole]

What cam are you running?

[bigdavec1974]

I'm not sure if I'm honest. It idles quite smoothly so maybe standard. I purchased the car through a member here. Some photos on my profile, someone may know more about it than me :/

[francob80]

If it helps, I have just had a carb rebuilt for me with a 0.9 ac jet, 1.3 2nd stage and 0.46 idle jet. Everything else in the carb is standard an I am seeing AFR's of 10.9 - 11.3 at 20psi/WOT.

[James5]

If it helps, I have just had a carb rebuilt for me with a 0.9 ac jet, 1.3 2nd stage and 0.46 idle jet. Everything else in the carb is standard an I am seeing AFR's of 10.9 - 11.3 at 20psi/WOT.

Seems a little to rich still I would be looking for high 11's @ WOT

[francob80]

Yep, not finished yet James. I'm just waiting for charge temp gauge and det cans before I raise the boost much more. The fuelling should be fine for a few more psi.

[bigdavec1974]

Bit of an update......
replaced the high output fuel pump and added a malpassi adjustable fpr.
No more ultra lean afr at 80mph.
Now she is slightly richer at Wot, mid 11's at 5000rpm in 4th @18psi
Dilemma...........
Up the boost slightly???

[francob80]

Bit of an update......
replaced the high output fuel pump and added a malpassi adjustable fpr.
No more ultra lean afr at 80mph.
Now she is slightly richer at Wot, mid 11's at 5000rpm in 4th @18psi
Dilemma...........
Up the boost slightly???

My advice would be checking your AFR's in 4th at much higher revs than, 6/7k and then see where you are.

[bigdavec1974]

Update ....
Afr 11.6 at 6500 rpm about as high as I dare take it haha
Slight rich but thinking of leaving it with a bit of a safety net. What u think?

Soon to follow self made electronic Det Can. Just to be 100% :)
Cheers all

[R5MJH]

id leave it, its nigh on perfect boss

[bigdavec1974]

I'll keep you posted about the det cans.
Cost less than £10 haha

Thanks

[bigdavec1974]

Another update.
After replacing the fuel pump and upgrading to a malpassi fpr I have the following Afr's.
Idle 14.7
Cruise 14.0
Wot at 6500rpm 11.8 @ 24psi.
Discision time........
Back it off or leave it?

Help.....
:)

[francob80]

Sounds good, I'd leave it.

Check charge temps & check for det to be safe.

[Matt Cole]

Another update.
After replacing the fuel pump and upgrading to a malpassi fpr I have the following Afr's.
Idle 14.7
Cruise 14.0
Wot at 6500rpm 11.8 @ 24psi.
Discision time........
Back it off or leave it?

Help.....
:)

That seems excellent! What spec is the carb now? Also how did you make the det cans?:D

[Alex]

Sounds good, I'd leave it.

Check charge temps & check for det to be safe.

Yep :agree:

[GTphil]

For that boost 11.5 is nice and safe. I cracked a liner this weekend at pod that was with flat 12 afr just over the line and mid to high 11's all the way through the gears at 24/25 psi. So your on the money with 11.5. :agree:

[bigdavec1974]

That seems excellent! What spec is the carb now? Also how did you make the det cans?:D

Hi mate, the carb is the same as when I purchased the car. I haven't touched it. Just a malpassi and a new updated fuel pump.
Think I'm gonna back it off to 21 psi and add an Aem methanol injection kit just to be a bit safer. Only £350 on eBay :)
Do aem do a charge temp gauge and probe? The digital type? I have a bit of a theme going on haha
The det cans were just a old folks listening aid called listen up and a 3 metre headphone extension. I cable ties the Listen up to a big crocodile clip and clipped it close to the original knock sensor. Takes some messing with the input levels but not too bad.
The engine sounds like just white noise but det sounds like the russling of crisp packets. There is a distinct difference.
Plenty of threads on the web from the ford boys

[francob80]

I don't believe AEM provide a charge temp gauge but you can buy many other brands for much cheaper than what AEM would charge. With regards to methanol/water injection I wouldn't waste your hard earned cash. Why not fit a bigger/better cooler ? Front mount perhaps? Cheaper and more effective.

[bigdavec1974]

I don't believe AEM provide a charge temp gauge but you can buy many other brands for much cheaper than what AEM would charge. With regards to methanol/water injection I wouldn't waste your hard earned cash. Why not fit a bigger/better cooler ? Front mount perhaps? Cheaper and more effective.

I hate the pipe run on a front mount, always rub on something. I have 2 grill mount ic and opted for the breadbin.