You need a tune... you should idle at 14.7ish. During boost you will see anywhere from 10 to 12 based on the map. I boost my car with 10.8 afr targeted. . Some go a little leaner. ..

So it sounds pretty close except at idle?

What will happen if it is driven this way?

Anything we can do in meantime? Planning on getting link this summer before a 16g

I remember back in the day when it tripped me out that the wideband would go dead lean pegged all the way when I'd let off the gas and engine brake...it's normal for these cars, don't let that trip you up.

The rest is just tuning issues. You could check for a boost leak(obvious first choice), make sure you don't have a vacuum leak on the intake manifold side, also make sure there are no exhaust leaks before the wideband sensor as that'll make it read wrong. The WOT lean issue makes me a little nervous, so until you can throw link in it, I'd avoid going WOT as much as possible until you figure out what's wrong. It should be pretty stable at 15.1 to 14.5(it'll go back and forth) and during WOT it should go fairly quickly(depending on boost pressure) from 13+ down to mid-low 10's. This is in stock form. If you're only boosting like 8-12lbs then the AFRs sound reasonably close.

Thanks! I figured the pegged lean on engine brake is normal.

BTW this is my first time building something like this and really first time hands on with turbos and so much aftermarket stuff.

The engine was just built, all new gaskets and all the clamps tight. I did do a leak test just for fun and it is slightly at the throttle body shaft seals, only thing that was not replaced... Its very minimal, though I am sure it is affecting the stock ecu.

The wideband is in the upper stock location, yes I have the 0-1v narrow sim going to the ecu, the flex part of the down pipe IS LEAKING. New manifold and turbo gaskets though.

Somthing you said confused me though

"The WOT lean issue makes me a little nervous, so until you can throw link in it, I'd avoid going WOT as much as possible until you figure out what's wrong. It should be pretty stable at 15.1 to 14.5(it'll go back and forth) and during WOT it should go fairly quickly(depending on boost pressure) from 13+ down to mid-low 10's"

That contradicts its self.
Did you mean IDLE lean? I have not gone WOT, only 3/4 (even at that it breaks traction in 2nd... Trying not to do that new clutch n all...) and it is down in the 10-12 afr at 3/4 throttle.

its stable 14.5-14.7 cruise and very light throttle

idle is 15-16

darknezz7 said:

"The WOT lean issue makes me a little nervous, so until you can throw link in it, I'd avoid going WOT as much as possible until you figure out what's wrong. It should be pretty stable at 15.1 to 14.5(it'll go back and forth) and during WOT it should go fairly quickly(depending on boost pressure) from 13+ down to mid-low 10's"

That contradicts its self.
Did you mean IDLE lean? I have not gone WOT, only 3/4 (even at that it breaks traction in 2nd... Trying not to do that new clutch n all...) and it is down in the 10-12 afr at 3/4 throttle.

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Sorry, should've explained that a little better. If it's randomly going from low 10's and creeping up to 12's as boost comes on at 3/4 throttle, I'd avoid going WOT or boosting it much in that situation. However if it's starting up near 13-12 and as boost comes in dropping to ten, that's normal.

Oh ok, no it starts at 12 then very quickly goes to like 10.5 and stays around there at 13psi 3/4 throttle. I have not taken it past 5k rpm either.

Oh yeah 1k idle vac is at 21, thats good right?

I think its all good except the idle

3/4 throttle and 5k rpm max and it is very fast, in such a little unstable car I should say... Still, fast, going to get it dynoed after next month but do you think 300whp is possible? I base that off that a stock gst with intake, exhuast and a few things is supposed to be 250. This is stroker, os valves, new engine and a few more things... Stock 2G Throttle body is a big restriction though.

Heres a pic, vac at 21, stupid cheap digital boost gauge stopped working and only went to -14... So big ugly non digital gauge stuck in that hole for now . Want plx boost and everything now hah.

Hard to say on the 300whp. The T25 really is a terrible turbo for trying to make any kind of power. It dies off after 5k rpm even on a 2.0L, much less a 2.4L. I think if you really, really pushed hard you could maybe possibly get close, but it would be an achievement. Realistically pushing it hard I'd say 250-270 front wheel HP, but I wouldn't expect the T25 to last very long. Lol.

Yea I was more thinking 270 at first, thought I'd throw 300 out there hah.

Its not going to get pushed in the meantime. But yes that is something, its a worn out used stock turbo already trying to move more air than it was designed for and I want to go and push it... Lets just stay easy til the rebuilt 16g...

Speaking of that, the 16g could run just fine with no extras than it already has as long as boost is kept at 13psi? Every things not gonna happen at once but I know the turbo needs replacing... Some in and out shaft play

darknezz7 said:

Yea I was more thinking 270 at first, thought I'd throw 300 out there hah.

Its not going to get pushed in the meantime. But yes that is something, its a worn out used stock turbo already trying to move more air than it was designed for and I want to go and push it... Lets just stay easy til the rebuilt 16g...

Speaking of that, the 16g could run just fine with no extras than it already has as long as boost is kept at 13psi? Every things not gonna happen at once but I know the turbo needs replacing... Some in and out shaft play

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Id at least get bigger pump and 550cc injectors for that 16g.. some will say otherwise im sure. But with the evo8 fuel pump (around 200lph with rewire) and 550s i never see higher than 70percent inj. Duty which is darn perfect IMO.. and if you look on here in classifieds you can get those for 150 or less combined

Its already got a walbro 255 rewired

I was thinking in the 700cc injector range so there is some more play room.

The car seems to settled down around 15-15.5 afr at idle so thats good.

darknezz7 said:

Its already got a walbro 255 rewired

I was thinking in the 700cc injector range so there is some more play room.

The car seems to settled down around 15-15.5 afr at idle so thats good.

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You'd be safe with 700cc... 550s do just fine.. 20g i would need 700s