My Dyno Result - Diognosis help please?

[Si.]

OK so Sunday UJCC held a Hampshire and Dorset RR day at Triton Motorsport in Bornmouth, and i thought what the hell, first opportunity to see what shes running like.

Now i have always thought there was a really bad flat spot after 5500 RPM, ie she jut stopped pulling. I also had concerns that she just wasn't that quick. Although she felt fairly quick, there were certain moments where the renouned performance of these cars was not stacking up against cars that had been "killed" in drivers stories and such like on here.

The dyno on the day has since come to light had a slight intermitant problem where the fly whell figures were really low, but it seems WHP is pretty good. Unfortunately i think i was not one of the unlucky ones and got an accurate (as best you can) figure.

I've attached the graph, and i'm a little trouble as to how i can solve the problem. Firstly i only pulled 185BHP at the wheels, which if you drive an auto converts to around 260 HP, but mine being manual means it doesn't infact convert to around 230 with the 24% losses expected.

It looks like the car is running really rich up until 5600, then she leans off a quite dramatically. Funnily enough this is exactly where i lose all my power, as you can see from the second graph.

It also looks like the car struggles to hold a good figure of boost, dropping off at 5600 RPM again.

Fairly impressded with the torque with around 245 ftlb at 3500 RPM.

Now what i'm struggling with is how to solve my problems and get her running back at least somewhere near the power she should be. With out full ecu mapping to remap the fueling and boost and such like, what are my options? What could be the cause of such poor performance? I'm a bit baffled and stuck, so any advice would be much appreciated.

[wrdmotorsport]

Hi Si , Looking at the stats you may have a weak FPR or fuel pump that can not keep the pressue when entering high boost/rpm areas .

Be aware that running the AFR around the 12 area on none forged internals can cause damange

[colVR4]

If you have not made any significant mods to the car then the graph looks about spot on for a standard car, if anything slightly better than expected. The fuelling for your car looks a LOT better than you would expect from a standard car...are you sure that you haven't got a piggyback ECU thing going on there or a fuel computer?

Only way to release lots of extra power is to get a boost controller, a free flowing exhaust, better air flow and a bigger front mounted intercooler (FMIC).

[Wodjno]

For starters your Fly HP should be 244bhp using 24% losses.. (185.6 / 0.76) So not as bad as you 1st thought..

The main problem i can see is when your boost is building ! The AFR should be dropping along the RED line that i have drawn on the Graph ... The box i have drawn shows that your AFR's are leanining out as the boost is building instead of getting richer..

As stated by WRD, this could be a problem with a weak fuel pump or low pressure of the FPR or even a crapped up fuel filter.. These would be the easiest to sort first

[colVR4]

The whole of the AFR graph looks too lean for a standard car. Are you sure that there is no fuel computer, chip or resistor or something that is leaning it out. There is no way that the AFRs shown there are standard.

[Wodjno]

The whole of the AFR graph looks too lean for a standard car. Are you sure that there is no fuel computer, chip or resistor or something that is leaning it out. There is no way that the AFRs shown there are standard.

The bhp and torque figures would be higher if it had been mapped.. !!

[Kenneth]

Have you done the "MAF Mod" Si?

the AFR looks fine to me, it leans out at fairly high rpm, which is normal.

[zentac]

It looks like you boost is dropping off quite a bit at the end, you may have a weak/leaking actuator that cant hold the boost correctly.

[Kieran]

Be aware that running the AFR around the 12 area on none forged internals can cause damange

Err? Really? Thought 12 was what we were all shooting for when on boost? 12 up untill say 5500rpm and then richen it up a bit to keep the EGTs and Cylinder temps under control?

[wrdmotorsport]

Max torque is at 11.8 , Max power is at 12.5

But these figures are based around having forged internals when I map my car it will be to 11.2->11.4 max as we are not 100 % sure on the strenght of the standards .

I know of one person who is running 12's but they have a tight control over the fueling and are as insane as me ( hello Glen )

[Wodjno]

It looks like you boost is dropping off quite a bit at the end, you may have a weak/leaking actuator that cant hold the boost correctly.

Thats a good point there Richard especially as he is only running standard boost levels


EDIT: ON FURTHER INVESTIGAION I SEE THAT THE LARGE PERCENTAGE OF STANDARD CARS THAT HAVE BEEN ON THE ROLLERS, HAVE FOLLOWED THE SAME BOOST CURVE..SO I THINK IT'S HOW THE STANDARD ECU IS MAPPED.. NOT A WEAK OR LEAKING ACTUATOR AS SOME OF THE MEMBERS CARS I HAVE CHECKED OUR NOW RUNNING MUCH HIGHER BOOST WITHOUT A PROBLEM ...


oops.. Sorry about the Caps Lock

[Wodjno]

Have you done the "MAF Mod" Si?

the AFR looks fine to me, it leans out at fairly high rpm, which is normal.

Going lean while the boost is building is far from normal Ken ??

[Si.]

Wow thats really thrown me.

As far as i am aware the car doesn't have any kind of fuel control. Obviously only have the car in the contry since October means i know little about the history, so perhaps a little more detailed investigation would be required. there is no obvious signs of a controller in the car, but that doesn't there isn't something hidden away. Anything i should look for, in specific places??

I know it has a Greddy speed limiter cut as the box was in the car on arrival.

I would have to say I have not done the "MAF mod" as i don't know what that is, and wouldn't know what to look for really...

It's quite amazing that there are a few that think the AFR is too lean, the guys at Triton were fairly concerned about the "running rich".

The only performance mod i know of is the exhaust which is an Apexi item, with the Cat still present. There is no boost control so standard boost is being used, so loosing some is a little worrying. It was mentioned by the guy who services my car that i may have a weak actuator after i told him about the result actually.

Even if she ran 244, still quite low i would say. I know she's a 10 year old car but for a car that should be 280 .....

So things that could do with attention for trial and error purposes:

Fuel pump
Fuel pressure regulator
Actuator
I'm thinking about a electronic boost controller anyway

Thanks for you help so far guys, keep it coming, all very useful info.

[Wodjno]

Wow thats really thrown me.

As far as i am aware the car doesn't have any kind of fuel control. Obviously only have the car in the contry since October means i know little about the history, so perhaps a little more detailed investigation would be required. there is no obvious signs of a controller in the car, but that doesn't there isn't something hidden away. Anything i should look for, in specific places??

I know it has a Greddy speed limiter cut as the box was in the car on arrival.

I would have to say I have not done the "MAF mod" as i don't know what that is, and wouldn't know what to look for really...

It's quite amazing that there are a few that think the AFR is too lean, the guys at Triton were fairly concerned about the "running rich".

The only performance mod i know of is the exhaust which is an Apexi item, with the Cat still present. There is no boost control so standard boost is being used, so loosing some is a little worrying. It was mentioned by the guy who services my car that i may have a weak actuator after i told him about the result actually.

Even if she ran 244, still quite low i would say. I know she's a 10 year old car but for a car that should be 280 .....

So things that could do with attention for trial and error purposes:

Fuel pump
Fuel pressure regulator
Actuator
I'm thinking about a electronic boost controller anyway

Thanks for you help so far guys, keep it coming, all very useful info.

So has the car just come in from Japan ??

[Kenneth]

Going lean while the boost is building is far from normal Ken ??

Interestingly enough, it is.
Had a discussion with a tuner over the dyno results from my Legnum and apparently Mitsubishi tends to tune them that way.
Apparently at that RPM the engine isn't supplying enough fuel to do damage (unless you get detonation) so there is no problem with it.

Check out my AFR graph...
The boost on the red line peaks about 11.5psi... its incorrect on the graph because their connection to the boost reference leaked.

[Kenneth]

a better boost reference... 15psi at 3000RPM and still afr of about 14

[amsoil]

Looks to me at about 5800 revs you are loosing either spark, (unlikely) fuel or air to keep up with the rising revs, If I was to take a stab at it I would say that your inlet is unlikely to be so very crap but your fueling looks to be the culprit.
But what do I know.

[Kenneth]

Si, are you running the standard bypass valve (BOV)?

I just remembered that at our first dyno day dickytim had poor performance compared to most (baring those of us who had faults) and later found his standard bypass valve was leaking.
The result was that his boost curve was essentially the same as yours!

He changed his bypass valve and got immediate results.



As you can see boost has same shape, max boost looks to be the same also.


Spark issues would likely show up similar to the blue line on the first of my graphs I posted up (as thats the issue I was having)

I still cant see anything wrong with the fuel...

[bradc]

Ken, while the fuel curve does lean out, which is obviously a good thing as far as performance goes, what the UK guys are saying is that it isn't normal for our cars to lean out like that, so it has to be one of two things:

1. ecu remapped at some point
2. screwed fuel supply which is causing it to lean out

I doubt it could be the first because and WODJ said, if it had been remapped it would be making more power in the first place. I would suggest there is something wrong with either the BOV, fuel pump or fuel pressure regulator and thats causing the lack of power. I would suggest it probably isn't the BOV, because if the BOV was leaking you would expect the car to be running really really rich (the maf counts the air, but the air doesn't get to the engine), and it obviously isn't running as rich as a stock car does.

[Kenneth]

Ken, while the fuel curve does lean out, which is obviously a good thing as far as performance goes, what the UK guys are saying is that it isn't normal for our cars to lean out like that, so it has to be one of two things:

1. ecu remapped at some point
2. screwed fuel supply which is causing it to lean out

I doubt it could be the first because and WODJ said, if it had been remapped it would be making more power in the first place. I would suggest there is something wrong with either the BOV, fuel pump or fuel pressure regulator and thats causing the lack of power. I would suggest it probably isn't the BOV, because if the BOV was leaking you would expect the car to be running really really rich (the maf counts the air, but the air doesn't get to the engine), and it obviously isn't running as rich as a stock car does.

I thought I posted a couple of graphs that CLEARLY show that the standard ECU DOES lean it out. All things working as they should, the ECU runs fairly well.