Hey, Just wanting to get thoughts and opinions on my dyno tuning graph, especially thoughts on the A/F reading. 105KW = about 150HP & this is from a JDM d15b running 6psi, otherwise standard engine.

 

Any info & suggestions?

 

looks a little lean to me at the start of boost...once you are in boost you want to tune to around 12:1 or lower to be safe..then progressivly gets richer..little to rich on the top end

that graph is kinda hard to read though

 

whats an optimum a/f ratio for a turboed car? So many people say different things, whats your opinions?

Rob

 

Through the mid range I think it is lean like from 96km to 124km I bet your boosting by then so your A/F should be below 13/1 at least.... That is unless I am reading the graph wrong

 

Ok, To be honest, I really need more info on reading this graph in terms of A/F ratio.

The car itself is running sweet although at around 6000rpm it feels a little hesitant but nothing really dramamtic.

Should the fuel curve look like this at all?

 

No the graph shouldn't look like that there should be the area when not boosting ie lower rpm that should be leaner then the rest like 14/1, then once in boost you should really have a flat curve of around 12/1 having it richer in the topend is a safety measure so maybe a slight downward drop into the 11/1 sort a thing. Your graph is some what like this but still lean through the mid range and then very rich through the top end .... Thats my take anyway someone else????

 

Ok, That sorts that out.

I would think if it's running as lean as it is I would be getting slight detonation? I guess the good fuel im using is helping me out? From what I can see there is no white smoke to speak of? What other things will tell me if the car is runing lean?

The car does feel a bit flat at high end which I guess is because its running to rich. Havnt noticed black smoke though.

 

Would Running my car with an A/F ratio as per the graph be dangerous?. I have been driving it fairly often for the past month (since conversion was complete) and havnt had any detonation what so ever.

 

looks way to lean to me, how come the dyno is not using RPM on the bottom side of the graph? looks like wheel speed in Kilometers? When I dyno with wideband, I like to keep them 11.8 ~ 12.5ish if I can..

 

Abaz - How would I actually tell if it was running lean, I havnt noticed white smoke, I also havnt had any detonation? any thing else I should look for?

 

What is your fuel setup because that graph is beyond nasty! You went from ultra anorexic lean to Mama Cass fat rich.

You want the car to run similar to an NA setup(14.3~14.7) when not in boost and have a AFR in the 12.0~12.5 range while boosting. AFR's in the 11's are good for saving the engine but if you go too rich you will foul plugs like madness.

 

i have the same engine and made 160who and 150tq at 7 psi...so ur right on the money when it comes to power...my engine is fairly strong and has held up to alot of driving and dyno runs...keep it 12:1 give or take .5........lean out the top a little and feel the increase power...i used run dead rich at the top and felt the power fall off almost liek it doesnt want to pull anymore....when i leaned it out it pulls hard to redline now

 

for the replys.

When I first got the car back, I didnt know alot about what the graph should look like, but now I know exactly & im not gunna drive the car to hard until ive got it sorted.

Im using an 'Intercept link' - air flow meter mangement system & a 'power link' - extra injector controller.

I think The jump from lean to rich could be caused by the 2 extra injectors I have mounted on the intercooler piping. I figure that the fuel isnt getting distributed between the 4 cylinders & 2 are running rich while the other 2 are running lean?. Im not completely sure though.

eg6 turbo - Yeah, thanks, Im hoping for about the same power as you once I get the tune sussed. I know what you mean about it not pulling up high when rich!, It feels really flat.

If anyone else has any other advice/infom feel free to contribute. Thanks.