Running rich on the dyno at top-end?

[T9 dreamer]

First of all thanks to Paul for organising the dyno day at Uxbridge last month.

Second of all, my car was putting less than I'd hoped! .

The guys running the dyno said the air/fuel mixture at the top end was "off the scale" (meaning less than 10:1) and I'm trying to get to the bottom of it. Anyone able to help? Make suggestions? Comments even?

Thanks!

Car is 1998 pre-Viggen Abbott'd 9-3 with Abbott ECU, Sports catalyst downpipe, twin back-box and other suspension mods, etc from new. (also... T5, Garrett T25, non-crossflow IC).
I have added Forge re-circulating dump valve, silicon tubes, MP rack clamp+brace. Crossflow IC next to go in.
Original claim from Abbott is for 250bhp - dyno result was a disappointing 211. (see attached graph)

[BlinD]

Check your fuel injectors. Make sure theyre not leaky. Make sure the DI is doing its job correctly. Check the fuel filter. Fuel Pressure Regulator. Something obviously isnt right. I know how ya feel though. My turbo honda always had the same thing. I'd smoke out the whole dyno.

[T9 dreamer]

Thanks BlinD.

I know the DI is good cos it's only 3 months old. Plugs too. Car's due 102,000 service so fuel filter could be an issue. I'll check injectors/FPR if I can get them out this weekend - any tips as to what I should be looking for?

Cheers!

T9

[BlinD]

Typically when you remove them. If they look like theyre covered in fuel or if they drip a little bit. And sometimes with them still in the intake manifold if u snoop around u can see some traces past the seals. Also it could always be a faulty tune or something. But hopefully its something easy. Good luck.

[T9 dreamer]

Thanks for that. Looks like another fun weekend ahead!

Cheers! - T9

[Jeremy R.]

A bunch of us from the Saab Club of Seattle ran our cars on a dyno a while back. Most of the newer ones, including mine, ran really rich at the top end. I don't know if they running as rich as yours, but they were dumping a lot of fuel into the engine!

[T9 dreamer]

Maybe it's a more common issue than people realise then - you have to dyno your car to find out? At least it's safer running rich than running lean!

Regarding the low power issue rather that just the a/f ratio, I've emailed Abbott Racing and they said that it's not uncommon for power to creep downwards over time because of weakening boost pressure. I'm hoping to check this soon with a pressure gauge I won on eBay - maybe then I'll get to the bottom of it. In the meantime it's raining outside just now so I think I'll be in the garage and try to get a look at these injectors!

Cheers - T9

[Alex]

I would certainly check the boost levels, have Abbott told you what you should be running at?

Atleast with a T5 car you won't have problems with air leaks in other parts of the system as it is MAP only which will help with searching for the problem.

It is also possible that the mapping is out and that the car is running rich. Do you know if the ECU was mapped on the car, or just a mail order one?

[T9 dreamer]

have Abbott told you what you should be running at?

The guy from Abbotts have suggest he can give me some of the numbers when I get proper boost values so i just have to wait to get the gauge and hook it up.

Do you know if the ECU was mapped on the car, or just a mail order one?

The ECU was mapped on the car at Abbotts at new with 3 miles on the clock from the documentation I have. Would the fact it was hardly run in at the time make much/any difference?

Cheers - T9

[Vigge]

Do you have a a/f plot of the run? It would help

[Rob Sandey]

When we checked your wagate acutuator at PE it wasn't opening at all So you ECU isn't controlling it. Don't know the effect of this on your BHP but it probably points to some issue that may be relavent.

[T9 dreamer]

Do you have a a/f plot of the run? It would help

I'm afraid not - the guys just read it off a gauge next to the dyno and that data wasn't repeated on the graph plot unfortunately. The "off the scale at the top end" and "that means less than 10:1" quote was all the info I have.

When we checked your wagate acutuator at PE it wasn't opening at all So you ECU isn't controlling it.

Yeah I remember that and mentioned it to Abbotts but they didn't come back with any info on that yet. As I recall the actuator moved but was very stiff (~12psi) and only moved a few mm. Mind you the engine wasn't running at the time so no ignition on -> no power to ECU???

Also on that issue I have a spare actuator on a turbo I bought from ebay - I might swap them out and see if there's any difference. (I checked doing the injectors job in the Haynes manual - that looks like a bu$$er of a job so I decided not to bother just yet and see if it comes up in the service report).

With any luck my boost gauge will arrive some time soon and I can get some numbers out.

Cheers - T9