Not a "lean" spike, but its goes leaner to something around 12.5:1 from what i can make out, which is still on the rich side!

Isn't exactly lean man, 12.5 is too rich really.

Iv tried mine at a variance of AFRs under wide open throttle (as it would be on rollers) currently goes around 12.5 then fades to about 13:1, slightly rich, but in the past I had it around 13.8 and it didn't perform so well.

People get hooked on 14.7 which isn't good for making power or protecting your internals as such.

Maybe drop your main jets 2.5 sizes and try again, but I'd imagine there's more to it, changing it by 1 AFR makes a difference, but I doubt 30hp.

How is your ignition setup? How can you be sure your cams are right? Being regrinds surely they need setting up not just wanging in to standard marks?

Timed a cam 180 out? Max sells/sold verniers, get one, take nicks advice on carbs, drop 2.5 and try again. :-)

Edited 21 September, 201213 yr by POLOMON

Surely thats too lean? Although I'm assuming that AFR gauge was shoved up the tail pipe, so any leaks in the system would alter the readings (making it look leaner), providing you had some

Ben - that would seem about right, the main comes on around that rev range, although I'd expect the decline to be more gradual, as both pilot and main are used right up until roughly 80% wide open. But I guess it looks about right

Lean?? Is this why yours doesn't work properly?

Also main jet virtually effects the whole range, and needle position and profile.

You can almost tune around the pilots tbh.

I have back to backed a lot of settings on the same day, same route, same AFR gauge, and know what effects what, as apposed to going by what iv read on the Internet, be cautious giving out advice if you don't know yourself, especially with engine tuning, because you wouldn't feel great if he blew it up following your mislead advice. 12:1 AFR is not lean on an NA engine mate

IIRC he's had the dizzy re-profiled by H&H, and was first to have it done on here?

Definetly far too rich, from what i can see (I'm on my phone with a shit screen) its 10:1 at some places?

I've had a proper look at the graph, i get it now! Sorry, learning the hard way there I've never been bothered by carbs but always up for learning something new

Goes about 11.3:1 I think at the start then settles about 12:0ish through the range, rich yes but maybe not massively. Mine goes rich initially too, think its possible too soft a slide spring.

Carbs are the best

Its extremely hard to tell where the AFR is at from the graph, as the numbers drop off and don't seem to line up with the horizontal lines.

Get my PM ben?

Addressing a few dyno-related comments from the last couple of pages,

You really cannot compare figures achieved at different garages, using different dynos, on different days, with different ambient conditions.

Dyno days are good for comparison between vehicles, as the operator, dyno, ambient conditions are the same, but keep an eye on the location/ values of the intake air temperature probe.

Dyno Dynamics are fairly accurate. Here is a graph showing VW factory claimed figures for 2.0l 16v ABF engine vs. figures from Dyno Dynamics of a standard engine with typical mileage on it.

The plot shown on this thread will be accurate as to what the engine output was on the day @ that location.

:-)

I also just thought, running with the bonnet open generally makes it leaner, not so much with carbs at the back, but it does still. So you're probably even richer than you think.

Idling, if I close my bonnet it effects the AF about 0.5, but maybe more due to heat soak.

It's definitely rich though, I'd try get a day at a rolling road sorted.

cam timed 180 out.

Doubt it would run a 15.5, or even run? :s can you even time it 180 out lol?

Sorry, I'm such a spaz. of course its Rich. Ignore me, it was early

Haha ok man! :)

Will be following this closely, I'm intrigued.

Have a look through some of Leeds_finest's old threads. He has RR printouts of his at various stages of tune, making more and more power, sure it lists various changes and stuff!

Doubt it would run a 15.5, or even run? :s can you even time it 180 out lol?

Well a 8v....Yes, yes you can..... Dont ask!

Doubt it would run a 15.5, or even run? :s can you even time it 180 out lol?

Well a 8v....Yes, yes you can..... Dont ask!

You only managed it because you took the vernier pulley apart and put it back together wrong. With a standard pulley you would have to set the timing marks out by 180. On the afh you need to set the dots on the cam pulley so they are facing each other so really it would be impossible to set wrong if you even had the slightest idea of how to set the timing on the afh

Doubt it would run a 15.5, or even run? :s can you even time it 180 out lol?

Well a 8v....Yes, yes you can..... Dont ask!

You only managed it because you took the vernier pulley apart and put it back together wrong. With a standard pulley you would have to set the timing marks out by 180. On the afh you need to set the dots on the cam pulley so they are facing each other so really it would be impossible to set wrong if you even had the slightest idea of how to set the timing on the afh

You know, i never even thought about the stock vernier on this.... I knew the reason i did it and didnt apply it to this atall! dick headdd I'll go quiet again, forum seems to work better then :p

My money is on the very rich mixture, and the carbs not being set-up, this is going on the knowledge that the engine is in good condition...

wasn't this set up at bogg bro's or is my memory fucking with me?

Nick, wasnt Leeds finests' an 8v?

Yea it was setup at bogg bros, however since then i had the dizzy retuned and had all the bottom end work done, but i didnt how that would affect the fueling so left the carbs untouched and just kept them in balance and check them weekly

It was, but it showed how the states of tuning effected the power

Yeah, I see your point Nick.

Craig, any work done should really be followed by checking the timing and fuelling again. If only to make sure nothing has changed. Just taking the carb off sent mine out of balance. Though I still can't see this accounting for the lost ponies

Also, have you measured the specs on the cams? Far fetched maybe, but have they been reground properly?

Edited 22 September, 201213 yr by prankstar2003

Your 1/4mile trap speed and power figures tie up. Stock G40 will trap about 85mph/87mph with 113bhp.

Rolling road is more than likely correct.

Your 1/4mile trap speed and power figures tie up. Stock G40 will trap about 85mph/87mph with 113bhp.

Rolling road is more than likely correct.

interesting!