What kind of power can I expect to see with a 11.5 afr rather than my current 10.3/10.5 afr's?

I'm asking this because I'm having problems making the power that I think I should. I haven't dynoed the car but with what my car weighs and what it traps, the power is right around 389 to the tires. I'm running 19psi with a hks t51r kai and a street port. The reason my car should be putting down more power is because my car trapped almost the same at 12 lbs.

Something is holding the power back, I just need to find out what......

 

Can't help you there but I am tuned for 12's and the car put down 409rwhp at 14.7psi. Problem with me is slow boost and also not difference in power between 14 psi and 18psi

This on a T04B 60-1 .96A/R

 

at ninteen psi yer way off....its not a point of fuel that is going to get you to the numbers that turbo is capable of on a street ported motor.

whats your compression?

are your trailing plugs firing?

is your turbo sound? just because you are getting 19psi doesnt mean you are getting proper flow


there are only so many things it could be.

 

im no expert...but your issue sounds like a flow issue....had the same prob trying to run my m2 twins thru a stock cat 14psi felt the same as 18psi....removed the restriction and zoom zoom zoom. granted my turbos were sound and the rest of the vehicle was put together properly.

 

Your car is tuned for low to mid 11's on the dyno Did you not watch his WB when SK was tuning?

It will lean out slightly on the street, so it should be perfect.

 

I know that I'm way off. This is why I posted. The turbo is fine and boosts correctly. Haven't done a compression test but I'm getting aroud 16 inches of vacuum. My trailing plugs are firing yes.

I'm thinking part of it might lie in my air filter. It's been soaked by rain soooo many times it's not even funny. My car sits outside so when it rains or snows my filter takes all the abuse because it sits right under the hood vent. Anyone know if rain etc etc etc will hurt a cone type filter? Even after it's dried out?

Just throwing ideas out there...

Not getting any ignition breakup either so that's not a problem.

 

put a screen filter on the turbo for temporary?

with 379rwhp my best trap the 1 time I went to the track was 120.8

I'm confused about your problem as well. everyone is an idiot on this forum so youll have a hard time getting help.

 

I'll try the screen thing this week for the heck of it. Hopefully it won't lean out. I went 11.54@123 with what I've got but I should be around 129mph with 19psi.

Anyone have any ideas?

 

Give us the breakdown of your entire setup. What IC, ect, ect, ect.

Honestly it sounds a lot like some boost leaks I've witnessed on other cars. I've watched cars on the dyno with boost leaks and it seems like no matter how high you turn the boost they barely make any more power. A lot of times the boost pressure will rise but the power doesnt, the reason is the turbo over spins to compensate for the leak and it ends up running out of its efficiency range and not making any more power. You might get it on the dyno and make some 19psi runs and feel around to make sure the bov isnt leaking when under pressure, and check all your couplers, ect. Also, while on the dyno you could pull that filter off, that way the wb will tell you if you start to go lean. It sounds like your missing a lot of air, I would definatly be carefull and do this on the dyno cause if you fix whats wrong your probably going to go seriously lean.

 

I think what you've said is the best way to go about this. I would think if I has a boost leak I would be able to hear it ya know?

mods are

aeromotive 1000
upgraded -10 lines from motor to pump and return
aeromotive fpr
1300cc sec
950cc primary
power fc
street port
greddy 3 row
hks super sequential bov
hks t51r kai kit
open exhaust
I think that's all that's relevent.

 

Nope did not watch the wastegate

I'm following this thread since this is the same problem as mine. I thought that SK said it was 12's.

 

If my blow off valve were leaking, wouldn't I be able to hear it? I'll try tightening it down some I guess........

 

yeah, the bov is a relavent performance mod...

 

when i was on stock twins, i only made 7 more whp by going from 11:1 to 12:1. i'd guess at the most, you'd get 15 extra horsepower. these things have to run extremely rich to be safe. my car is tuned extremely rich, as in, i saw 9.x:1 when it was being tuned, and i'm laying down 439 to the wheels on 16psi. it sounds like the turbo is extremely inefficient at that boost, your timing is off, or you have a miscellaneous problem that just hasn't been located yet

 

i'm going with timing issue on this as well. i've seen HUUUGE differences because of simple timing problems. just double check it to be safe.

 

He would not tune 12's between 15-17 psi. No way.

 

the reason i'm on my second motor

well that and the stock intercooler at 15psi just didn't seem too efficient

 

Not always, I've seen some leak on the dyno where I had to put my hand infront of it during a run to tell. There is no much other engine noise that it just drowns it out.

 

I dunno, I'll have to look at all of these things. I figure I'm off around 100 hp so I've most likely got a few things to figure out.

 

easiest way to look for boost leaks is to go down to the local hardware store and buy a black rubber pipe junction with 2 clamps that fits over your turbo intake and a plastic end cap to plug the other end. The buy a air compressor fitting and "install" that in the plastic end cap.

clamp too turbo and pressurize with air compressor. Some will leak past the engine/throttle plates, but not a signifigant amount like you would think...

Depending on where your BOV references manifold pressure...before or after the throttle plate...you can test that as well...just by opening the throttle and see if the leak starts or stops on the BOV.

air pressure is air pressure...whether the engine is running or not.

john

 

Didnt read entire thread.. But yeah.. Definatly sounds like a flow problem.. Any big bends? what I/C? there something not flowing well it seems.

 

greddy 3 row intercooler......... no crazy bends. I still think that if I had a boost leak then it would be somewhat erratic. My boost holds strong and steady.

 

anyoe have some ideas?

 

Not talking about a boost leak.. But something that is hindering flow.


Usually sharp bends or drastic reductions in i/c tubing size. Stuff like that becomes alot more apparent on higher HP motors. or motors with very large flowing turbos.

Maybe post up a picture of your setup Someone may see something?