Thread: Ignition Timing Tuning Questions.

I have the probe in the hottest cylinder so I fail to see why you can't tune for the maximum temp in the hottest cylinder. The coldest cylinder won't give my much info.

This is going no where, do they make a fwd s13?

you cant always use that guideline.
What if one of your injectors is not flowing like the others and its not giving as much fuel as the others? Just saying your logic is flawed.

just b/c you are using the S13 base map doesnt mean anything definitive. I used settings in my tune from the S15... but i still have a FWD SR20 engine..

That is a good point, I did not think of that.

How-ever if I take my car to a dyno and I only had one cylinder drilled and tapped, are they going to drill/tap every single cylinder and attach a probe in all? Or are they going to tune for the one I have?

First off forget using the egt numbers. Unless you read all four cylinders. the reading from one cylinder only tells you what is happening in that one cylinder. You can use the egt as a reference along with the af ratio. I tune by load,tps and afr. The aem tuning guide is a good place to start. You can also take efi classes which is what I would do. Learning the hard way by blowing stuff up gets expensive quick.

they make clamp on bands with a type k thermo couple. they mount on the outside of the manifold. The only issue with that is you must know the formula for the metal of the manifold so you can figure out the internal gas temp from a external manifold reading.

Absolutely agreed, I will definitely have a read on the aem guide. What EFI classes would you recommend?

About the clamp on EGT sensor, I guess you could just compare the clamp on egt reading to the probe and adjust the factor and know what the temp inside is. the only problem with reading the outside of the tube is there will be a significant temperature difference from the metal heat soaking across the welded joints will be different, as well as if the pipes are not identical in shape they will all head differently, ie bends and straight sections.

Cool tools though!


Thanks.

Ok so now you know everything about the car, do you have some ignition timing tips?

EGT temps? you dont tune for EGT temps you can use it as a safe guard to prevent going lean/HOT/detation which all ties in

your A/F will read your overall air/fuel ratio, once you set your A/F you can start with timing

EGT can give you a idea as to when you are knocking however that will vary from motor to motor as the batch of the cast pistons can go either way.
i like street tunes as i have had a few street tuned but unless you have a good knock detection system to get the best, safe, power set up a dyno is the way to go.

if you insist on go forward i will suggest you leave the timing as is tune your A/F then take it to a dyno and rent it for a hour or 2 and play with the timing. once you see what your timing is doing to the motor with every pull you will see in the graph once torque starts dropping you will know you are around where it wants to be.

basic rule of thumb is -2degrees for every lb of boost during ramping.