Thread: GTIR SR20VET Dyno Predictions: Going with VE Intake and Xcessive Plenum :)

Yeah that makes sense, but I'm just seeing if there is some sort of formula or how to even see if your combustion improved.

For those that are curious here are the two dwell tables from TunerCode and a stock B13 bin.

Tuning dwell times are car dependent. No two cars have identical spark characteristics.

Honestly, I would consider setting the dwell tables above when initially setting the car up with the modifications you had done. From that point, they shouldn't be modified. Much like adjusting the K value, etc.

I'm curious too how one would go about verifying the changes you are making are going in the right direction... would you just have to make repeated dyno runs to find out where the car stops making more torque? Monitor AFRs? or is it more of a massage game; adjust the dwell/adjust the fuel trim...

I'm thinking you will see slightly more torque, but the real difference will be in AFR's. Also if you have an EGT, you would see higher EGT's due to a more complete burn, theoretically speaking.

theres alot of good info in this thread.

makes you think alot. makes you think that when you have some one tune your car they arent taking any of this into consideration. their just sitting the car, nailing the throttle punching a few keys on their laptop, making some acceptable numbers and putting their hands out for payment. who knows our cars better then us.

its nice to see, a sr20 guy know how, what and why everything works and how to make power.

stratton.

In reality you want to have as long of a coil dwell as you can but a coil charge will not always get stronger the longer you hold it. There is a cap where it doesnt make a difference. Each coil is different. Best thing to do is find out the specs on the coil if using aftermarket coils or if using the stock Vadim just gave what the factory ecu is programmed for for dwell times and probably are best suited.

Obviously with one single coil firing 4 plugs, at high rpm your dwell time will not always be reached as there simply isnt enough time. Thats when at high rpm and power levels you will start to see ignition cutout because of a slightly weaker spark due to the shortened dwell time. Thats why using individual coils makes such a difference. You could have the same strength coils but have 4 of them and you can make more power simply because of the ability to increase the dwell time especially in the higher rpm range.

Strat,

AEM is good about setting proper and the most efficient dwell times based on what coil your using. Any good tuner should check to make sure the coil dwell time is set properly in the AEM to match the coil and setup your running. There are big differences.

ashton, i understand the basics, im a total tune noob, but this thread alone has given me alot to mull over the next few days.

i enjoy speaking to people who really know these cars.

for example, everytime i speak to jamie, he gives me a few things to think about for the next few days.

stratton.

Strat, made a small correction to my quote. Follows the same thing I said just a different way about it. Can you correct my quote so there is no confusion.

Here is a screen shot of how the aem sets up dwell time based on battery volts and rpm



While those same lines on the CDI settings are flat across for battery volts at 50% dwell time and preset dwell time is 100 mS no matter the rpm.

That's very true, this is why I chose to learn tuning the car myself. But another thing to keep in mind when your tuning a Calum or Nistune ecu (Without TunerCode) you are VERY limited on what you can tune. So your tuner does have his hands tied based on what you give him to work with.

I don't even see the ability to tune Dwell time on a regular tune.