OK 221 HP is all the car would put down on the local AWD mustang dyno, which reads EXTREMELY low in RWD mode. I realize it was very very hot, seeing as my intake temps were well over 140-150 at some points, but I shouldn't be missing this much HP. Something is definitely amiss, and my a/f ratio at 10psi (where I was only putting down around 209hp) was in the 11.5-11.7 range all the way across the board.


But I'm still missing some power, and I mean in a decent size way considering the the mods I have, and since this dyno was at 13psi.

Mods:
2mm Street Port
Intake
DP, MP, CB
Non-Sequential stock twins
Power FC w/ Datalogit access
Bigger SMIC
1200cc Secondaries
Supra Pump


I'm going to attach my .dat file from the datalogit, and the dyno sheets are below:


Dat file:

http://www.carforums.net/RX7dynotune.dat

 

I know this graph shows a pretty rich A/F ratio, but it's not rich enough that I should be losing massive ammounts of power either.


Engine has been compression tested btw, and it put out 90psi on the front housing and 95psi on the rear. It's got less than 2000 miles on the rebuild and is street ported like I said above.

 

sorry i cant help you tune it i have similar mods not the injectors and i have sequential twins though but i dynoed at 13 psi 290 hp and 263 torque with the base map the power fc comes with

that almost 14 to 1 on the wide band o2 is really bad btw you want more fuel than that i belive we tuned my car for an 11 to 1 air fuel.

 

Where do you see the car hitting 14.1??

 

Your compression is only 90-95? That's HORRIBLE!

From your graph, the AFR looks like it's dipping below 8.0....which would be insanely rich. Your transition is really bad too...what's happening with your boost pattern there?

 

The car is running non-sequential


As for AFR, the richest it goes on the graph is 10.7 if you look at the bottom it says the minimum AFR, average, and max.

I am not sure why the compression on my rebuild with less than 2000 miles on it is so low. The car had a proper break in and never saw more than 9psi of boost until the dyno night, and even then it is tuned extremely rich with retarded timing.

I need some major help, I'm getting ready to give up on this stupid car. I've poured all sorts of time and money into it, but it's just giving me grief at this point.

I was told 90-100psi is alright as long as it doesn't go below 90 I shouldn't see any big HP difference. Not sure if that is correct or not, but I searched and quite a few people said their car only had that ammount of compression. I know it should be 105+ though, especially since it was recently rebuilt.

 

I see why you think the graph is going into the 8's, the right hand column is boost level, not AFR.

It seems my non-sequential twins are spooling up very very late on the dyno too btw.


On the street I see full boost around 3600 RPMs, not sure why the spool up on a loaded mustang dyno is so slow.

 

You have some serious problems with that motor/setup.

First, ignore the table at the bottom. If you look, the black line is AFR. It clearly dips to 8.0 AFR.

Your torque curve drops a ton right where the normal transition would be and also builds too quickly for non-sequential.

90-95 psi is pretty much the compression you see right before you rebuild an engine! A good rebuild should be above 120! Your motor is crap.

Given your motor condition, there could be a lot of other problems with the car as well. I can't look at your .dat file until I get home.

 

^ I agree with Ryan. Look at your black A/F ratio graph again. It starts out fine then has a weird jump back upwards during staging. Then it goes really low below the 8 ranges at 4,400rpms. This is an indication that your secondary's are dumping in way too much fuel. What your graph is showing compared to the printed out numbers is 2 totaly different things and incorrect. Your black line should hit the 11 ranges at around 4,500 rpm's and level out there to be safe. Yours keeps going down below the 8's which is way too rich. Also who rebuilt your engine? Your compression numbers are lower than they should be. I suspect improper corner seal to side seal clearence.

 

Read my last post about the 8's

As for the motor, I agree something seems weird with the compression numbers.

I might try another compression tester, and see what happens with that. The reason I think something is up, is because the car doesn't like to hot start. But other than that, I have no signs of low compression, the car idles perfect and feels decent when it pulls on the freeway. I'm really not sure what is wrong. Like I said, I'm getting read to just park it and say screw it for a while. It's beginning to really frustrate me

 

You guys are mis-reading the graph. The green section to the right is boost, the a/f ratio scale isn't present on this graph. I'm going to the dyno again in a few days to watch my buddy, I'll have them print me a graph with the AFR scale on the right instead of boost.

The numbers at the bottom of the page are correct, I wideband logged it myself with my own wideband, and it is 100% correct.

 

lol, im having flashbacks here >_<

My car has very similar mods, street port, 3mm seals, nonseq, full exhaust, ecu and injectors.

I only made 255whp on rx7store's dyno during the tuning session due to some bad ignition equipment, I found out later that my coils had gone bad.

The car pulls fine under WOT? Could it be something related to ignition? My setup I was expecting well over 300whp even at lower boost - but the ignition problems totally fucked me over.

 

I don't know, but it pulls hard at WOT with 10psi on the freeway. No break up or stuttering, AFR is a solid 11.6-11.7 all the way accross.

I'm not going to buy new ignition equipment at this point, because I don't believe my problem is ignition related at 10psi of boost. Just doesn't seem feasable. I'm going to try to compression test a friend's FD with my compression checker (if he has time) and if his reads substancially higher than mine and it isn't the gauge reading low, I'm ripping my motor out and we're going to have to take a look at it.

This is really depressing

 

From what I notice is.....

AFR instability, Boost Creep

If you have spent tons of money on the car what is another 300-400$ to get it properly tuned by a pro?

Good luck,

Alex

 

Find me a pro that will come tune my car for $300-400 and I'm down lol.


Actually, I am heavily debating renting a car trailer and taking a road trip to Gotham Racing or Maybe even to Rotary Performance in Texas.

Besides those two places, I don't know anyone in the surrounding area that is really considered a "PRO"

I've heard decent things about a few tuners in Cali, but nothing major.

 

In all honesty though, why pay someone to tune the car when I have all the tools and cabability to do it myself? I just need some help / insight, fuel tuning is cake. The only thing I'm still learning is timing for this car.

 

You would pay so that you don't have any mistakes a sudden 15 AFR and pop goes the motor!

Other than that you would pay lets say in the case of Steve, because he will already have maps made similar to your setup and all he will do is fine tune them. Also because he will diagnose problems that you couldn't find in a long time within 15 seconds.

My 400$ was well spent!

 

Problem is, I can't take the car to Texas to have it tuned. It won't be relevant to my real driving conditions in Vegas.

Unfortunately there isn't a big market for FD tuning in Vegas, we might be lucky to get 5 cars for him to tune, and I doubt he has the time to come here any time soon. So for now, I'm on my own.

 

A couple things.
I know on my Mustang Dyno the boost and AFR are going to use the same numbers on the right. So to me it looks like the AFR is in the 7's although I have never seen one get that low before.
By looking at your DAT file did anyone adjust the fuel? Looks like a stock map almost.

 

The fuel is adjusted for all the boost cells, we richened the whole map. Then in some of the idle cells which don't matter I have done some work. Besides that, it is a base mod fuel map


I'm telling you guys, the AFRs were not in the 8s lol...I don't think his wideband can even measure below the 9s.

What do you think of the timing in the dat file? Honestly I don't know what to think, I'm just frustrated now, that's why I'm tuning to you guys. I really need some input about the whole situation (motor and all)

 

get a real wideband and don't rely on the dyno's wideband, could be that the dno is just not calbirated properly and putting down low HP numbers also.

 

I have a wideband permanently mounted in the car, it is a TechEdge / WBO2.com unit that read exactly what the dyno's wideband said within a .1 variance.

 

who built your motor? i know of a motec tuner in san diego...

 

Is this the 3rd run? Looking at your pim voltage and PIM values, you did not reach 10 psi.

How does the car run on the street?

If it is running good, at least take it to another dyno.

 

Books,

I have no idea what run this was. We made about 20 runs on the dyno that night, but unfortunately my logging person sitting next to me didn't save the runs each time, I thought he was doing so but he was just pushing start and stop thinking they were saved automatically.