hosrom_951

The turbo teg, as in the Acura Integra vid? if so, i saw that, and i saw HIM throw flames.......or was it you

special tool

Slimboy - it was pretty lean, man. The dyno operator dropped the throttle at 5500, so as no to blow it up - he was obviously watching the bar.

hosrom_951

Err.....no, he was getting leaner after 4.5K ending up at just under 14.0:1

Running rich from 2K~up to 4.5K, from there onwards to 5.5K running leaner.....

hosrom_951

Basically he was reached really rich at max tq numbers........

special tool

Hosrom - is that a response to me?

Oh, it was. Have you ever been to a dyno, man? The operator will drop the gas if the a/f spikes toward 14 on a turbo car, sport. Especially at high revs. When those guys get a Porsche that they have never tested before, the first few runs all they do is watch the afr bar at the bottom of the screen.

hosrom_951

Special Tool: Unfortunately, i havent had the luxury of a dyno ($220 for a single run w/o a/r readings, just flywheel power here in this ****).

And yes, hitting 14+ a/f on boost would get people's heart pounding

And i also agree with you when you said

"When those guys get a Porsche that they have never tested before, the first few runs all they do is watch the afr bar at the bottom of the screen"


since experience on porsches is always better.........

I though you read the graph the other way (lean mean anything below 12.5:1) because that is what i though at first when i heard of a/f ratios

Sorry for all this confusion

boosted951

Thanks for the input guys.... I am going to have to do the oil pan gasket soon...In the directions Clarks-Garge has...you have to remove the injectors and fuel rail anyways, so it is a perfect time to do it....

boosted951

bump

porshhhh951

it was me i was the car on the right

boosted951

Any recommended size fuel injectors? 55lbs/hr or 72lbs/hr... I only want 350 hp at the wheels...or as close to 400 at the crank as possible....LOL I know I have a ways to go though..... just want to make sure I get the right size for future upgrades....

boosted951

I know this is probably a no no....but can I just get a better fuel pressure regulator instead of injectors? Or is that the lazy cheapo way to do it... Would bigger injectors be the best along with a FPR?

m42racer

If it was me I would check your Fuelling or chip first. Your highest fuel demand will be at peak torque. Its not unusual fir the fuel to be leaner by design at the high RPM's. If it does not detenate or make more power, having more fuel there makes no difference. Very common for the fuel curves to be leaner there. Take a look at a typical fuel curve from any Turbo engine and it is almost flat across the RPM range and dips at the higher Revs. I would check the detenation first, then adjust the mid range fuelling to get a more normal looking curve. It should lean out at the peak torque. Keep it safe though. Then if the duty cycle of the Injectors is reaching 100% or close at the higher Revs, try adding some more static fuel pressure. You will have to adjust for this across the board. Depending upon your increase, you can calculate the increase in fuel delivery. Looking at your upper end, I suspect this will work just fine. Measuring the Injector duty cycle is very simple. Do all of this first before jumping into new bigger nozzles. Checking the detenation is always a good idea, whatever the mapping result. Travis sells a neat little Plug and Play knock system which tells you if the engine is knocking. He also has a new system which can be adjusted for different engine fequencys, and outputs into standard CD type headphones. Very cool. I think these sell for around $ 200.00 or less. Cheap insurance. Another thing to keep in mind here. You can fool an O2 sensor when running rich. O2 sensors are looking for oxygen in the exhaust. If you fill up the exhaust gasses with a lot of unburned gases, it takes up the volume normally held by the oxygen. Now the sensor reads lean, when in fact its rich. EGT's and other inputs will tell of this. Be careful in your case as you are very rich in the mid range. This could be happening. To be sure without other inputs, do a full power run and cut the Ignition/ power at the high Revs and check a plug. If its reading rich and the sensor is reading lean, then you are in this fault. If the sensor reads lean and the plug reads lean, then the info you already have is correct.

boosted951

thanks m42racer.....I am going to try to get my car dynoed again soon to see if I can adjust the AFC as well.....when I replace the oil pan gasket...I have to remove the injectors anyways, so I figured it would be a perfect time....LOL

boosted951

Getting my car dynoed again Sat....hopefully I will have another A/F graph to show an improvement...LOL

turbite

I think there is something to be gained by messing with the AFM (if you have one). Its worth a try anyway.

You could tighten the effective spring on the AFM so that it goes full open much later in the rpm range. You'll need to retune everything. I think that will make the linear climb start much later in the rpm range and give you much better overall AFR. And as other said, you might be maxing out the injectors, but I doubt that happens at 4000 rpm.