edomund

I'm finally going to dyno my TII next week. (just finished breakin)

This is my first time dyno tuning so I need some pointers,
ie af ratios, gears to run, things to watch.

Mainly I'm going to be tuning my S-AFC to get my af ratios correct, I've heard around 11:1 is safe.

I fully understand how to tune the s-afc I just need tips for the dyno.

edomund

What type of af ratios are good for no load (no boost) (lo settings on the s-afc)?

I do a lot of freeway driving so I'm going to do some cruising type pulls on the dyno (simulating cruising in 5th on freeway).

Wankel7

I would say.....

1. Replace the plugs before you dyno run. It will burn. Wear gloves!

2. A 3rd gear pull would be a shorter pull and maybe easier on your car

3. If it is a dyno jet facility request your data files on disk. You can download a run viewer from the dynojet website. Maybe bring your own disks. I am not talking about the pictures. But the data files.

4. If you have the TMIC ask if he has a water spray you could mist on it. It will help a little bit. Or just bring your own sprayer and have a friend do it. Maybe used distilled water.

5. Make sure the straps in the rear don't get to close to your exhaust and melt it.

Thats about all i a can think of.

James

edomund

Thanks

So basically I just set my s-afc rich to begin, to be safe.

Do a pull, check the af ratio for that pull and then lean out the numbers a few points.
Then do another pull and repeat until desired af ratio.

Do the af ratio #'s appear on the monitor while your doing the pull? how does the program work?

wozzoom

Plugs: I always change my plugs in the parking lot prior to putting the car on the dyno. First time I dynoed the car, the plugs had 2000 miles on them...I had some ignition break up on the top end. We changed the plugs on the dyno and I picked up 6 RWHP!

Fuel: Fill the tank with Premium. The best you can get! Then add a bottle of octane boost to the tank for protection.

ilike2eatricers

Would filling up with higher than 91 octane effect the dyno tuning other than the safety net it provides? I mean since you are tuning the car with higher octane (lets say 94) are there any effects running what one would use normally such as 91 octane?

I think the general concensus is that octane booster doesnt really help at all since whatever the number is on the bottle it is only .X. I guess anything to help stop detonation.

wozzoom

The higher octane is just for protection. It won't effect the overall tuning of the car.

If you have access to Ultra 94, go with that.

Wankel7

I am not sure about that.

How do you know it would not affect the tuning?

James

edomund

Calling all who have tuned an s-afc on the dyno.

Any tips for tuning my s-afc on the dyno hi and lo especially cruising?

wozzoom

Because your car can't tell the difference between 87 octane and 94 octane...

edomund

I'm tuning for af ratio and on pump gas since thats what I'm going to run (92 I'm in cali thats all we got). Enough about octane.

I need people who have dyno tuned a TII with an S-AFC.
Pointers?

wozzoom

How do you have the S-AFC hooked up? Are you using the TPS signal to switch between the high/low map, or are you using the boost sensor signal?

This isn't real rocket science. The S-AFC is not a stand alone ECU... when you start on the dyno and get the wideband O2 sensor warmed up, you'll do a couple of light runs in gear. This will tell you where you A/Fs are at and you'll make some adjustments to the S-AFC. Then you do it again with more throttle... repeat until you're at 100% WOT. Done. You'll have your high map done.

The low map isn't as important in your car... Just use the high map as a reference and tone it down a bit. Done.

edomund

S-AFC is hooked up to TPS.

I know it's not rocket science, damn what is it with this forum everyone has to be a smart ***.

Anyway I just have never been to the dyno before and want some people's methods on tuning there s-afc's, things to look out for and things to try.

wozzoom

I'm not trying to be a smart ***... After re-reading my reply I can see how you can take it that way. Sorry.

Anyway, since you have the AFC hooked up to the TPS you won't even be using the low map. Just put the crossover point at 98 low / 99 high. Tune the high map for your A/F and you'll be all set. The low map can be set pretty much at 0 because you'll never see boost on the low map.

I doubt you'll be on the dyno more than an hour. Just be careful with the A/F's and back off the throttle when it gets close to 13's. Let us know how it turns out.

edomund

No worries man.

Thanks for the pointers, but I can't leave my settings at 0. I have 4x720cc injectors, that would be crazy rich for the lo settings.

Thats why I need some pointers before I go I can only tune for 1 hr right now and need to get the most out of my time.

What af numbers are good off boost, still around 11, even for cruising down highway?

ilike2eatricers

Well even if the car cannot tell the difference between octane levels, tuning with 94 octane for example and running high boost you do not detonate on the dyno BUT when on the streets running that same boost with 91 could be potentially dangerous.

Any insight on this?

edomund

ahhh!!! hijackers

wozzoom

I see what your getting at. So you have the S-AFC set to take fuel out now?

Off boost, you'll be fine in the 12-12.5 A/F range. This will give you better gas mileage when cruising. The only problem you're going to have is with the cross over point on the AFC. The TPS on the S4 cars reads 100% when your only at about 25% throttle. So most people in your situation don't mess with the low map very much.

Just get the car to idle well with the low map. Don't waste any dyno time trying to tune the low map. Focus on getting your high map set and you'll be safe.

wozzoom

This is sort of true. You're not tuning the car for the octane your running. You're tuning the car for an A/F number. You will get the same A/F number running 91 octane and 94 octane.

edomund

Yeah I have the s-afc to lean out the 720 primaries.
I probably will be taking out fuel not adding fuel with my injectors.

I really want to tune the low settings for when I am at around 3500 rpms in 5th on highway.
I commute around 90 miles a day and dont want to run stupid rich during freeway cruising.

1. But I'll do the high settings first (on boost) in say 4th gear pulls.
2. As well as set the idle to around 12:1.
3. Then I'll do the 5th gear lo setting af ratio for cruising on highway.

Sound like a good approach?

wozzoom

Step 1 is fine. This is where you want to spend your time.

Step 2 could be leaner. Idle can be as high as 13-14:1 without any problem. Personally I just play with the AFC until the idle is smooth.

Step 3 might be interesting. If you get a chance, put the AFC into 4-channel mode and watch the "Throttle %" when you are cruising in 5th. I know on my 86 NA in 5th gear, it's very hard to maintain speed at 75 MPH and keep the throttle under 98%. Downhill? Yes. Uphill? Never. This is why its nice to use the Boost Sensor output for the AFC.

*edit*
You may want to consider switching the AFC to read the boost sensor before the dyno so you don't have to go back and re-tune.
*/edit*

edomund

Thanks I'll try 13.5 at idle.

Cruising in 5th on freeway it's usually uses the low settings for me unless I am speeding up and slowing down.

I think I can get the low tuned for freeway with tps for now, but I might end up going pressure sensor.

Thanks

edomund

anyone esle have anything to add?

BDC

Yes. I would be extremely careful with this combination of stuff. It's very volatile.

B

edomund

BDC care to elaborate on your statement.