[Moorman]

It's done, the results are in, and it all makes sense....right? :-/

Run #1
http://speedtoys.com/~moon/1986/dyno/dyno09.gif

Run #4 (jumping over 2 tuning attempts)
http://speedtoys.com/~moon/1986/dyno/dyno12.gif

Pre-MAF run
http://speedtoys.com/~moon/1986/dyno/ldyno04.gif


It looks like there's room for improvement, as I'm running pretty rich, but clearly something wasn't right with the dyno, because according to the chart I briefly went back in time towards the end on both runs!
The first 2 tuning attempts I made were aborted each time it hit the lean spot ~4300rpm due to excessive lean, and I only got a little closer by my 4th run (he gave me an extra free run). What I'm trying to keep in mind, is that all my previous dyno sessions showed a 2 to 3 HP loss on successive runs, so factoring that into the gain achieved by the 4th run makes it easier to stomach. A gain of 3HP (5-6HP if you count the aforementioned loss) for a change in A/F of ~0.4 should point to a decent gain if I can get the a/f's closer to 12 and more linear. Surely another 6-7HP could be had. If those pieces can come together, I can get closer to the 10hp gain I expected from this deal (on a stock car mind you). How much can a better intake help if the exhaust is left restrictive?

So initially, I was disappointed with the numbers, but after having a few hours to mull it over, it seems to make sense to me. To inject a side note...my old Mk3 was there also and we gained 20hp by leaning a/f from ~9:1 to 10.5:1


...maybe a stock car wasn't the best guinea pig after all. BUT, my SOTP meter still tells me the car runs stronger, despite the numbers. I further question their accuracy, since my old Mk3 at 8psi ran a 14.6 1/4mile @98mph, but the dyno showed it only making 202hp, while in Vegas @ 12psi it put down 276hp.

Next paycheck I'll try a different dyno.

 

[Supra Bob]

Umm... :shock:

I think thats about the screwiest dyno graph I have ever seen. I would say that the dyno is certainly not running right....I think you and Vern are suffering from the same malady... whatever that is...

Did you get any torque readings? Even when screwed up, torque is a less subjective number than hp... Its seems like you were not getting a good signal from the Tach to the dyno...

 

[Don L.]

:roll Well, it seems your dyno numbers (for hp) aren't too far off from pre-MAF considering the car may need a bunch more tuning. Sure it looks like its running rich, maybe much too rich. Did you have any previous dyno runs with a a/f printout ? Most of my recent dyno runs range from about 12:1 on the a/f at low rpm (2k) gradually rising to about
14:1 on the higher rpm (above 4K). Something about the ECU, seems always gets leaner above about 4K (kinda like in your graph), although your graph was more a temporary lean then richens up a bit again.
I would like to see the a/f ratio in the power band closer to 12.5:1 to 13:1.
I would guess your seat of the pants sensation is due to a increase in torque at the lower rpm ranges. Hope you can lean that MAF out some, otherwise you also run the risk of damaging the cat.
Like Bob said, that was a pretty funky looking dyno printout. Was that dyno done in 4th gear ? A graph with hp, torque, and a/f would be ideal.
Hey, at least it runs ! Now its all about the tuning !!

 

[Supra Bob]

OK...been looking at this some more...

From run 1 to run 4, while the peak has not changed much.. if you look from about 2900 up to 4700 rpms, the hp curve rises quicker on the 4th tuning than on the 1st... I have to agree with Jaosn here... I think getting this thing tuned to a 12 to 12.5 to 1 a/f ratio would easily see 10 hp...

 

[Moorman]

Just to help visualization on that thought...

 

[sloopercat]

Interesting, I know dynos are different, but my basically stock 84 did 152HP at the rear wheels. I had punched a couple of holes in the airbox and have a 2.25 Brullen exhaust.

Maybe there is something else not up to snuff on the engine that is hoding it back?

 

[Supra Bob]

Actually..I think your two "little" mods may account for the difference. M series motors respond almost insanely well to intial breathing mods... Plus, Jason is in Cali, which tends to have lower dyno numbers anyway...

I think with a 2.5" exhaust.. he would probably put down alot more numbers..

 

[quick]

Looks like they had a hard time... Don's right -- we need to see A/F in order to understand how much tuning room is left.

Good luck with the next dyno. Mustang dynos are supposed to be the best for tuning, btw.

 

[MWebber]

Actually..I think your two "little" mods may account for the difference. M series motors respond almost insanely well to intial breathing mods... Plus, Jason is in Cali, which tends to have lower dyno numbers anyway...

I think with a 2.5" exhaust.. he would probably put down alot more numbers..

hopefully we'll have a dyno (still hunting a mobile down) at the M-A meet in June, I've got several more aggressive mods in the breathing aspect... I hope to have the MAF installed and tuned(mostly) by then....

 

[Don L.]

Wow, Sloopercat ! 152rwhp with just a airbox and exhaust mod ? That's really impressive ! Did you get a torque reading too ? The average hp numbers I've heard with mild mods on a 5mge motor tend to be around 125 to 135 hp at the wheels, and I thought that was pretty good considering stock motors are 160 hp at the crank. Another variable I've noticed is that on the same dyno, same day, I can turn 170 hp in 4th gear, but only 155 hp in 3rd gear. Go figure. I'll try to do all tuning on the same dyno to at least get comparative figures. Hopefully Jason will get some more tuning done and report back to us all.

My understanding is that lower rpms use a leaner mixture for throttle response then should richen up slightly when hitting the power band. Or do I have it backwards ??

 

[Supra Bob]

Nope.. your on the money

Less power requires less fuel... Plus max power is actually acheieved at ~ 12.5:1 A/F ratio... which is what the "open loop" map shoots for.

 

[sloopercat]

Actually I had it backwards, torque was 152 ft#, HP was 149.8. The motor is strong, all new ignition stuff in the last 3-4K. It does have a littler over 100K on it.

I have P+P shaved head and a DT header on it now. I just need to get it put back together and rerun it.

 

[Junkie]

I think his engine is tired or,the dyno is way off.My 88 Cressida with an 85 engine,stock as stock can be,thru the auto trans put down 126rwhp.My .02

 

[SilverMk2]

It says its a Dyno Dynamics dyno on the sheet. They supposedly read around 10% less than the Dynojets (the most common ones in the US), so the #s are probably about 140 on a Dynojet.

 

[Dzone]

I dont know much about reading dynos but Its really great to see how much HP we can extract from the 5m-ge
Maybe we dont need to swap engines( I would be happy with 250hp @ wheels)
look at Russ and hes got a 5m-ge!
just my 2cents

 

[SilverMk2]

( I would be happy with 250hp @ wheels)
look at Russ and hes got a 5m-ge!

Good luck even getting 200rwhp on a 5MGE. I can't even get close to that on my 6MGE. Even the 2JZGE guys have a hard time getting near 200rwhp. BTW Russ has a 6MGTE.

 

[Malibyte]

Just wondering if the GP is still on for this. As I recall, there was a
deadline date, and I also recall it's coming up real soon. However, I'd
like to see some documented performance gain before ponying up some
serious $$$....especially on *TWO* cars!

 

[Supra Bob]

Yes, the group buy is still on The info on it is in the group buy thread

Jason mentioned he was going to Dyno again this past Saturday... dunno if he did or not, or what the outcome was...

As for performance gains... The most I would expect to see on a stock 5M would be about 10 HP or so... BUT.. Phil D described this the best way that I tihnk possible... its a gateway mod. in itself its nothing big... but when you start adding other breathing mods (intake pipe, exhaust, porting, turbo etc..) is where the real gains and benefits to this are...

 

[Crocket]

re:

We'll although I would agree that this mode is a "gateway" mode, and it's true potential is to be had with forced induction/ heavy na mods. There should still be decent power gains to be had even on a stock car by just removing that damn airflow meter. I would assume that mass air flow sensors are more restrictive than speed density type systems, and switching to one of these is good for upto 10% power increase (or 15hp as seen on the SDS website). I think we'll see more representable power increases with further/proper tuning.

Sonny

 

[Supra Bob]

I completely agree that some gains with proper tuning are to be had... I tihnk the math works out to between 10 and 14 hp gain with nothing else changed...

The reason we have not seen it is simple. Bear with me, as a bit of an explanation is needed for me to fully paint the picture.

This fuel computer is a piggy back type computer, and functions exactly like the Apex-i S-AFC with 4 exceptions.

The first exception is that the Apex-i will only put out the type of signal it takes in. So if you feed it an AFM signal, it will only output an AFM signal, whereas this is designed to take in one type of signall, and put out another. I realize that this is an overly simplified explanation, but its still accurate for the most part.

The second exception is that the Apex-i has a linear line of adjustment in the form of a high and low setting, whereas the converter uses a real 3-d map referencing rpm and airflow to adjust the fuel delivered.

The third exception is that the Apex-i offers a total of 8 or 12 adjustement points (depending if you look at a model I or II). The Converter offers 16 points (500 to 8500 rpms, at every 500 rpm increment), with a greater degree of adjustment at each point..

The fourth exception, and the reason that we have yet to see any gains from this thing, is this. The Apex-i takes in the signal, and immedately outputs the same signal until you tell it to adjust it in some way. The MAF converter works by taking in the signal, and then references that signal to the map you have built, and then sends out the signal based on what the map says it should send. The reason we haven't seen any real gains yet is simply because we have yet build a map that simulates the best possible map for a stock 5M.

Plus, I am not going to even begin to go into how much more precise and accurate a MAF is over an AFM...

I can tell you, beyond the shadow of a doubt in my mind, there is great gains to be had in this thing for both N/A and Forced induction cars. Unfortunately, right now all I have is my word and some mathematical numbers and forumla's to back me up until we can get a car tuned properly....