Disappointing

Long tube headers, exhaust, CAI, and Tune...seems like it should be more

http://www.bocsquad.com/images/monkee/g8dyno.jpg

Those 20s and the tinted tail lights are killing you man! No seriously though, the 20s don't help your cause much, but that still seems low. Each dyno is different. Did you dyno before the mods for a baseline?

I was at 313 HP and 323 TQ prior to my ARP longtube install, which seems to be right about where you are with the longtubes.

What's it run on the strip?

seems low ???

haven't had it on the track yet...i got it in early october and shortly there after the track here closed for the season. I will definitely be out there right when it opens again!

i suppose i shouldnt be so picky...its not like i put a blower in the thing

haven't had it on the track yet...i got it in early october and shortly there after the track here closed for the season. I will definitely be out there right when it opens again!

i suppose i shouldnt be so picky...its not like i put a blower in the thing

I wouldn't worry about it until you run it.

I take it you don't have a baseline?

You might have a slow dyno.

Have they dyno'd another G8 there? Dyno's vary so much without a comparison its hard to tell how low it really is.

Does seem a little low with everything but hey, like everybody has said here, the strip is where the true gains show up with your performance. Dont get down until then!! Good luck and it still sounds awesome!

Disappointing

Long tube headers, exhaust, CAI, and Tune...seems like it should be more

http://www.bocsquad.com/images/monkee/g8dyno.jpg

Look at my sig and my dyno numbers. They don't match to well. Take it to the track and kick some ass.

do dealerships have the ability to flash VMS tuned ECMs back to stock? I understand they are locked to editing, but if they can be flashed to stock, maybe the dealership did it when they did my CASE relearn

I dunno, just a thought...and the guy doing the dyno said that i was the first g8 he has even seen...so they have not dyno'd any other g8's

my air/fuel ratio was just under 14

Does seem kind of low for a dynojet reading.. I was expecting it to be readings from a mustang dyno, but as always all dynos are different. Track times dont lie, so go test her out.

do dealerships have the ability to flash VMS tuned ECMs back to stock? I understand they are locked to editing, but if they can be flashed to stock, maybe the dealership did it when they did my CASE relearn

I dunno, just a thought...and the guy doing the dyno said that i was the first g8 he has even seen...so they have not dyno'd any other g8's

my air/fuel ratio was just under 14If your a/f is truly just under 14:1 you need to have it retuned IMMEDIATELY!! that is way to lean and you WILL melt down your engine running that lean. target a/f should be around 12.8:1.

I would not focus on the end numbers as much as the gain. My car made 293rwhp in stock form and then after mods it made 334RWHP. a gain of 41RWHP....that is the important number. Would it have been any different if it layed down 310RWHP stock and then 351RWHP after bolt ons? still the same 41RWHP.....see what I mean?

don't get into racing dynos.....they are a measurement tool to measure your gains as you modify your ride. The key is to use the same dyno every time if possible, so you have some amount of continuity.

yes, my average a/f ratio was just under 14...started out at just above 18 at around 50 mph

ill post a scan of the chart later when i return from work.

Panther8...what you said scares me...because my car definitely didnt smell happy going that fast on the dyno...smelled like burning :(

what do stock ecm's put out as far as a/f ratio?

I am with Panther8, something is wrong. The tune you got from VMS, was it for a car with headers? Headers alone can lean out the AFR so a tune that is not for headers could lean it out too much. It could just be that the SLP headers are not as good as the other long tubes but i think there may be something else going on. Can you post your graph as hp vs engine rpm? There seems to be quite a hitch in the curve a 90 mph like some timing may have been pulled. Also do you know what the blue portion of the graph represents?

Also on the whole dynos are inconsistent thing, yes there can be some inconsistency between dynos but usually dynojets (and other inertial dynos) are pretty consistent between one another because they are pretty simple. The dynojet is just a big spinning drum of a known weight. All that is measured is how fast your car accelerates the drum and from that torque (then hp) is calculated. The only other input is the weather correction which on most newer dynojets is handled automatically by a weather station attached to the dyno computer. So unless there is something wrong with the weather station sensors or a mechanical problem with the drum (bad bearings, misalignment) it should be pretty consistent with other dynojets. Other dynos that use load cells for torque measurement can have more variability due to the requirement of calibrating the load cell.

yes, my average a/f ratio was just under 14...started out at just above 18 at around 50 mph

ill post a scan of the chart later when i return from work.

Panther8...what you said scares me...because my car definitely didnt smell happy going that fast on the dyno...smelled like burning :(

what do stock ecm's put out as far as a/f ratio?stock the car runs in the high 10's to low 11's....pig RICH. You need to stop driving your car and get it tuned with a wideband immediately.

have you heard it pinging yet? If nothing else return to the stock tune until you can get it tuned correct. You can and will cause permanent damage to your engine running that lean!!!

what exactly does pinging sound like? What should i be listening for. I havent noticed any extra noises since header installation except for the hiss/clicking sound from the front left of the car is now louder...which i assume is the intake taking in more air than before. I have noticed a slight squealing type sound from the same area between 1800 and 2000 RPM on the way up...but that happened before the headers too.

When i put in my order for the vector tune...i put down intake, headers, and exhaust as mods...so it should have been programmed for all of my mods.

Here is the graph showing RPM and i also added the airflow graph

http://www.bocsquad.com/images/monkee/g8dyno2.jpg

is it possible that too high of an air to fuel ratio during load on the Dyno could have caused knocking thus pulling timing...therefore giving me lower numbers?

Yes, a lean condition combined with the advanced timing most likely in the VMS tune could cause a knock condtion that would set off the knock sensor and pull timing. This could cause the hitch in the curve and lower hp even more than the lower power output that you would get by running lean. I would contact VMS about this and see what they have to say. As far as frying your engine, I don't think 13.9:1 is going to kill a NA engine as bad as Panther8 thinks. I would just not spend much time at WOT until you get it fixed.

awesome, thank you very much for your help racerns

How did they measure the AFR? Did you have the WB installed in front of the cats?

With my VMS tune, I was running 11.9ish under WOT.

How did they measure the AFR? Did you have the WB installed in front of the cats?

With my VMS tune, I was running 11.9ish under WOT.

From the way it starts out ultra lean I would bet that it was in the tailpipe and the sensor was seeing some ambient air until they hit the gas.

yes, it was in the tailpipe. Should i have seen something more around 11.9 or 12 with the mods i have?

I guess it would be good to know the threshold as to what the highest af ratio is that will not cause knocking in the G8. I'm assuming its about 13.8 or 13.9 since thats right around where i was bouncing.

see that dashed line on your graph? that represents the maximum a/f ratio. You should be at that line or below it. 12.9:1 is my personal threshold. I have seen several engines 'meltdown' from running too lean. You can break ring lands on the pistons and all sorts of fun stuff, so yes it is a big deal!!!

Running the wideband after the cats has no effect on the reading. Most tuners run there setups in the tailpipe for dyno runs and they are not showing readings that lean. No matter how much timing you pull out of the engine it will not change the fact it is lean. That is a product of fuel trims not timing. Get it fixed ASAP and keep your foot out of it.

It is hard to describe what pre-igntion knock sounds like. Should sound like a ping that increases with the throttle. Maybe like if you shook marbles inside a coffee can.

here is a good picture of what running lean can do to your engine....

http://www.modularfords.com/forums/attachment.php?attachmentid=6124&stc=1&d=1083637303

holy crap! :eek:

One thing to realize here is that 13.9:1 AFR is technically not running lean. It is leaner than you want to be for optimum power but still richer than stoich. Remember that when our cars are not in closed loop (WOT) the computer uses the O2 sensors to keep the AFR close to 14.7:1 (stoich) and only when you get above 14.7:1 are you technically considered lean. All I am trying to say is that I don't think you are going to fry your engine (like the pic above) at your current AFR unless you plan to stay at high WOT loads for a long period of time. You do need to get this fixed soon though. Have you called VMS about the issue yet?

yes, i just talked to kirk about it. He wants me to get some fuel trims at idle and 2500rpm so im about to go out and do that

unfortunately, where i got my dyno done, they did not hook up the odb2 so i dont have any datalogs for the dyno...

Kirk also said that with my combo, he has never seen below 355hp on their Mustang dyno...so there is definitely something wrong :(

I dynoed mine with the LTs only and made 324/334 on a DynoJet with AFR at 11.7, since then I've added New Era CAI and UDP, added 6 deg timing and tuned to AFR of 12.6 on 93 octane E10. I have not had a chance to dyno yet, but it feels quite a bit stronger with the tune.

yeah...kinda the same thing i did with my mods..started with a CAI tho and modded quite quickly (in a span of about 2 weeks) and i could realllly feel the huge power gains each step of the way.

Here is a question about Dyno's...since i am a noob to them and dont know how they really work...

If the A/F censor on the AutoDyno was broken or malfunctioning, would that actually make the AutoDyno itself slow down to avoid breaking the engine since it thinks that its running too lean? Is it some kind of safety feature in the Dyno, or am i just a dumb noob?

Unfortunately, during my runs, they did not hook up an OBD tool to get fuel trims and such...so i really am left with no clue as to why my numbers were so low.

Oh, almost forgot, not sure if it really makes that much of a difference, but the highest octane they sell in WA is 92...and i have the 93 VMS tune...

I read the whole thread to see what octane you were running. Anytime you get spark knock you are going to lose some timing, then of course, power.
I have roughly the same set up as you and I dynoed 362 HP, 368 tq.
I do get 93 octane though.