Bump

More info added.

 

With one we hit 12.5 at around 4500 rpm's and then the a/f climbed to 14.1 by the end of the run, with the stock tune installed. We made 9-11rwhp and Tq on the stock tune with the " No tune intake" installed on Mitchstang's and OnemeanMarines cars but we didn't install a stock airbox on Sodaman's car so we didn't get a baseline from his to compare to. His car was the only one that hit 12.5 during the run.

As for o2 sensors, it's not a a/f ratio but rather a percentage of adjustment in the PCM. Once it has reached it's full adjustment then it defaults to Open Loop mode and then sets the CEL. This is ONLY in closed loop, not WOT, so at WOT the a/f can do anything it wants and since the 02's dont report to the PCM what it is doing then it can be at any a/f and the PCM wont detect it. This is why you should check it with a wideband.

Yes, the 20hp gain was with the " No tune Required" intake and my 87 Performance tune, also with the factory MAF sensor installed in the tube. I had to correct the a/f and then do some of my other adjustments and we made the power.

I printed off all of the dyno results for each owner so they can freely post the information with a/f ratio's on their graphs.

thanks, Doug.

 

Hey Doug just filled up with 91 and loaded your 91 perf tune it was barely above the emty line so it will take just a bit to get whats left of the 87 out of the tank. Looking forward to seeing and feeling improvements tommrow.

 

Doug,

Just a quick thanks for all you did, enjoyed the whole day ,except for the cold...LOL. Sorry I lost you guys after dinner, turned around and there was nobody there.lol. but had fun anyways.
Still dirving with the performance tune, will change over to the racing tune this weekend and see what happens. Too short of a drive to work and back to see what it will do.
Also, thanks to Bean and Andy for setting the whole thing up. We need to get together for some other social events with our cars, Looked cool in front of Harrah's with all of our stangs lined up, we needed pix!

As soon a I find someone with a scanner I will get my Dyno sheet posted.

Also was great meeting a chatting with the rest of the group.

 

OK Doug, when are you going to make a trip up to the Northeast? Any chance you can show up for another dynoday if we can locate a shop? Feeling awfully left out! Can't wait to see the dyno sheets!

 

About the a/f ratio on the GMS intakes, there were 3 at the dyno and all 3 ran lean. After Doug's tune they were around 12.5 across the RPM all the way to WOT. I feel a lot better KNOWING my car is safe and making the most useable power now. I would suggest a dyno and tune to anyone running a "no tune required" intake.

 

So all 3 cars with GMS intakes ran lean? That is very interesting. I do not have a lot of knowledge on tunes. The reason I bought the GMS was so I did not have to change the tune for warranty issues, as many others have as well from what I have read. With this issue with the lean fuel, what affect does this have on the car and will it hurt the engine or parts? Again, not a lot of knowledge about this.

 

Burnt Exhaust valves
Loss of Power
Melted Piston
Discolored Pipes
Blown Head Gasket due to overheating

That's worst case.

 

This is why I was curious as well. When I got my car dyno'd the a/f leveled out nicely at 12.5, so I'm not sure how all 3 of these didn't.

 

well they definitely didnt on ares. what to you mean by leveled out. It should be constant or near it the whole time. There were points where it was about 12.5, but most of the time it was outside of that, and at a point I believe we reached 15 to 1.

 

Well here is eci's dyno, on his second run his a/f jumped up to almost 16 it looks like, and that is with a tuner. http://forums.bradbarnett.net/showpo...&postcount=123

And here is mine, jumped up upon initial WOT, as expected, and then adjusted and compensated, and leveled out at 12.5. And like I said earlier, around same peak hp and torque as #10. I haven't done a stock base run yet so have no idea how much of an increase, but I will soon.

 

05GTRedfire: are you running a GMS CAI w/ their MAF only? (no tune, no other performance mods). Thx.

 

Yes, no tune.

 

Well after mine was tuned, there are no jumps up to 16 or 15 at any time, wot or not. You should not be seeing lean conditions under wot or not at any time, and then level off. after my tune it is now clearly between 12.6-12.8 all the way through. Constant!!!!! I think the granatelli piece is a nice piece, just suggesting a tune. Take it as you will. I know that mine is tuned properly now.

 

OK, am I the only one who doesn't get that? I don't understand how you can not have an initial fluctuation. If you stomp on the pedal, and the t-body opens up and starts sucking in all this increased air, wouldn't it be normal? If it stays constant no matter where you put the throttle than isn't that tricking the ECM into seeing something that it's not? Is this really what a tune is doing? What does the a/f do stock when you go WOT initially? I don't know, but I will soon.

 

The accelerator pump function would compensate for the sudden increased airflow. If it is tuned perfectly there would be no lean spot. I don't know about tuning these ecm's, but I had an AEM standalone system on my Supra and it had an adjustable "pump shot" just like on a carburetor. If it was adjusted too aggressively the engine would go rich the instant you opened the throttle.

 

Assuming most of the cars had cats, where was the exhaust being sampled to determine AFR?

 

The a/f would start off rich without a tune, mostly in the 12.5 range @ idle until the PCM would take over and then correct it to around 14.6:1, closed loop operation. When you goto Open loop at WOT the on Sodaman's it went to 12.5 instantly and then at about a 45 degree angle it just kept getting leaner until it hit around 15:1. On others it just stayed at or around 14-15:1.

As for a/f sampling it was taken at the tailpipe but I find this is well within .1-.2 of actual a/f numbers as I've tested with my own car with a pre-cat LM-1.

I would post the sheets but to keep myself out of legal matters I cannot...even though they are truthful. Any of the " No tune intake" owners can post thier sheets though as they are their property.

Thanks, Doug

 

Doug,

Quick question. I bought a SCT Tuner from you with your K&N tunes a few months back. After doing these dyno sessions, have you changed your canned tunes at all?

 

Cleaned up 05GTRedfire's plot and converted to jpg.