I'm interested to know what the best ways to measure performance when street tuning are. I have a B18 non-VTEC with stage 2 cams so it doesn't really make a ton of power. Sometimes I find it difficult to measure whether power is increasing or decreasing for certain RPMs. What are the best methods you guys have found for tracking this?

 

If you're at a point where you can't "feel" a difference, this is where a dyno comes in. You can only do so much on the street without any reference.

 

The problem I'm having is that I know my timing curve is wrong. As I advance my timing, I make less power at the top and more at the bottom. But determining at what point in the RPM range I need to split it is difficult.

 

That's why you use a dyno to tune your timing.

 

Its like trying to drive blindfolded... You just wont know till you get it on a dyno.

If you're making small changes at a time to your timing map (and you should be). Then you shouldnt "feel" a difference because it will be so minor. If even you are that good, how will you know where in the map you need to pull or add timing. You need some sort of graph to overlay and adjust accordingly otherwise the tune will be off. Im not saying its impossible... But its really trial and error and then still not sure, Lol.

The best you can do to tune timing without a dyno is take the car to a track, learn to read plugs and watch for detonation like a hawk... Still alot of guessing involved.

I would use a stock timing map, tune your AFR via wideband and dont touch the timing till you get the car on a dyno... Just my opinion.

 

use your datalogs for info... if you have VSS vs time you can do some math to calculate acceleration vs time

 

Thanks mikesrex. I think that's what it's coming down to. I've downloaded the source to FreeLog now. I'm trying to find a way to use one of the Extra fields to automatically calculate acceleration. It's a real pain to do a run, pull the CSV file, load it into OOCalc, run the formulas, and then compare to previous.

I'm also going to hit up the author of the android datalogger to see about adding an acceleration vs RPM graph where TPS > 90%. I can't believe that something like this isn't already done.

 

Use digital dyno, its fairly accurate if the CVS file is pretty on point.. its normally within 15% stardards.

Learn to read plugs, one of the most important things..among other things.

 

About reading plugs, do I have to use a new plug for every pull?

 

To properly read a plug, you need to make sure you have a new plug in, and drive around with it for a bit, it needs to get really hot before you can accurately read its contains..

I suggest when you go to start tuning, a new set of plugs..

Be looking for a solid black fuel ring, and your timing mark to be around the 90 degree bend on the strap. Heat range will be noticed by the discoloration in the threads, you'll want at least 3-5 threads colored to know you have the correct heat range..

After you're done tuning throw in a new set of plugs.

 

when I run at the track I put in a new plug in #3 for every pass while I am getting my tune right. At my home track I kill the motor before getting my timeslip and put in an old plug in #3 before driving back to the pits.

The dyno apps are pretty cool too. You should be able to use those apps to get information. Since I have time between runs on test and tune days I just do some basic math on my CSV file to get some acceleration numbers for each run. That way when I save the run file every graph and analysis I do is still on the file for future references and comparisons.

 

So that's an affirmative? I need to use a brand new plug for every pull? I want to do it right so I don't have to do it twice.

 

It's a good way to do it. You want to see what it looks like after a pull, not 2 or 3, then you'll get a different look.

 

and if you really want to get into it, you can shut the engine down from wot at various points through the rpm range to check how the engine is operating at specific rpms. in the past ive done this usually shutting down right around 6000-6500 rpm or just after peak cyl pressures. if i get the timing right in this part of the map, then from there up to redline i can usually add back in a few degrees(check it again though). the amount you can add back in is largely dependent on your setup and its efficiency as well as the rpm you turn the engine to.


just remember when you shut down the engine you loose vacuum for the brake booster, so you'll only be able to pump the brakes a few times before the pedal gets hard, so pick a long, straight, no traffic place to do this. last thing, id avoid 2nd gear for this, just make sure that whatever gear you use you are not breaking/loosing traction. reducing load on the motor will not give 100% accurate readings

 

What he said. Make sure you set timing relatively low and work your way up. Tuning timing on the street is pretty much guessing blindfolded. Another way you can do it is do one pass and datalogg it. Then do another and check both dataloggs and see how long it took you to reach desired rpm/speed. This is not the most effective thing to do, but if its the only option then do so. Dynotuning is the most effective for finding MBT.

 

are u talking about the distributor? or ecu? advance/retard i mean

 

I've been using Crome to do it. I've done some pulls and had moderate success. Some of the pulls looked correct, others looked like I didn't get the plug hot enough, and others looked like I had done multiple pulls (probably from not being easy enough on the throttle while driving before the pull).

Anyways, I've run out of spark plugs so I need to get back to the store and get some more. I want to get it right and be sure I know what I'm doing so I can methodically repeat the process. I'm into going faster but I'm just as much into the science of it all as well. That's why I started with a non-VTEC non-turbo so I could learn what I needed to know to build up a good B20 VTEC high compression setup.

 

[QUOTE=ALL M0T0R;46412061]Use digital dyno, its fairly accurate if the CVS file is pretty on point.. its normally within 15% stardards.

Learn to read plugs, one of the most important things..among other things

all motor how i learn to read my plugs what i must see ?my car is not programed yet i try to fix the fuel map low speen for breaking period of my motor

 

Where do you get Digital Dyno at? I'm trying to use Virtual Dyno and it's not working...

 

Digital dyno.? I use virtual dyno for evos and subarus. Didnt know there was a program for hondas!!! Googling now bish!!

 

Virtual dyno works with Neptune and Hondata IIRC. Not sure about Crome etc. The only trouble I'm having is that my logs are getting noisy at high rpms so it's loosing accuracy.

 

vitual dyno, is what i ment. Ectune logs get gitty up in the northern rpms so it becomes very unstable.. neptune and hondata seem to work well though.

I worked closely with brad for a bit to help make the program honda friendly for a bit, its pretty on point.

 

you can use the dyno for the iphone its fairly accurate. they had a video and it was basically within 5% dyno numbers and 1/4 times. but even if its inaccurate it still shows you gain and loss in power using the gyro thing

 

Good Info! i just learned a couple of things. As well as, now have a real idea of how to actually do this on my car.
Thanx

 

For these purposes repeatability is far more important than accurate whp numbers.