just scheduled dyno session for this weekend--any tips?

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greg@berkeley

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Jul 12, 2004

#1

• Jul 12, 2004

• #1

i just scheduled a dyno session for this saturday afternoon. i will be using my tweecer to tune, and i think i'll be doing all the tuning myself. i've already maxed out the spark table to the limit of 92 octane. are there any tables besides the fuel table that i should be using to tune at the dyno? what a/f ratio should i be targeting? is there anything else i should play with? any other tips for my first dyno session??

thanks!

 

Killercanary

The car that set the bar.

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Jul 12, 2004

#2

• Jul 12, 2004

• #2

Greg, my first tip for you is to have them print off or have them save on a disc for you and excel type spreadsheet of everyone of your dyno runs with the hp, tq, and AF at every 100 rpms. they will NOT do this unless you ask. This is a mcuh more valuable tuning devise than a graph. My tune saves them for me on a disc so I can review them and compare them at home as I need to.

As for AF, NA cars typically like somewhere between 12.5 at 13.5. My car liked around 13.5. I don't have a tweecer so I can't help you with what to tune with in it, but I tune mine with the WOT_FUEL_MULTIPLIER in my eec tuner. If you have your sprak maxed out, try setting the global spark adder 1 degree less and 1 degree more than where it is now. On the graph and peak versus peak you may not see a difference, but when you line up two runs side by side in the excel file like I said, you'll see which one yields more power and where. This can help you to fine tune your timing tables by adding a little more or a little less where needed. This can be very time consuming, so you may want to gather as much info as you can, go home and look over your notes and the power it made at every 100rpm and come up with a new timing table. Also, typically adding timing tends to lean the car out a little. I was always told its best to get the timing right first before fine tuning the AF mixture due to this very reason. Hope that helps somewhat.

 

G

greg@berkeley

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#3

• Jul 12, 2004

• #3

thanks paul, that was very helpful. i'll make sure to get a disc. once everything is setup, about how many runs can i expect to get in each hour? that is, about how long do you usually have to wait for the car to cool down between pulls? i'm trying to get an idea of how many pulls i can expect to get while i'm there.

 

Killercanary

The car that set the bar.

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#4

• Jul 12, 2004

• #4

6 or so depending on when they start the clock... it takes at least 5 minutes to hook up the car usually. Gte to the dyno a little early so you have time to cool the car off before they start. They will normally get it up close to 180* before starting the dyno runs anyway.

 

G

greg@berkeley

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#5

• Jul 12, 2004

• #5

thanks again, paul. it should be fun! i'm excited

any other tips out there?

 

Killercanary

The car that set the bar.

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#6

• Jul 12, 2004

• #6

Make sure they have a big fan up and running in front of your car during your dyno pulls. Do you have the fan switch mod done? If not, maybe set your high speed fan settings to like 100 so they will come on just about as soon as you start the car, it may help.

 

G

greg@berkeley

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#7

• Jul 12, 2004

• #7

thanks for that tip. i'll make sure to have a tune w/a really low fan turn on speed.

 

GTJake

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Jul 12, 2004

#8

• Jul 12, 2004

• #8

Are you going to Brain at Hi-Tech? If you are, his dyno room is very nice. It has a very constant atmosphere in the dyno room. He will put fans near the engine so it stays pretty cool. What day are you going? You know Car Craft is this weekend in St. Paul, you should really check that out when your in the cities. It's definitley worth your time.

Brain is very helpful with tuning. We pretty much just tweeced my spark_altitude_table and spark_base_table. We also played with the target A/F ratio in the fuel_table_base_OL.

It's weird we set my timing to like 30* at .8 load in the upper rpms, but when I datalog it's getting something like 42*. I don't know what that translates to if it were to be just advanced with the dizzy, but it's probably somewhere around 18*.

Let me know what day and time your going. I might stop by.

Jake

 

RIO5.0

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Feb 16, 2001

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N.H.

Jul 12, 2004

#9

• Jul 12, 2004

• #9

I followed Pauls advice on the best timing before AF...i got 7 or 8 runs, in an hour...if the state of tune is purdy much right on, you should be good to go...just strap it down and play...

Guy I went to let me do all the wrenching, which i prefer anyway....that way you know its where you want things...I always cringe when he rolls it up to 3500 and then pins it til 6k....

Good luck...your combo should lay down some nice numbers....

 

G

greg@berkeley

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#10

• Jul 12, 2004

• #10

jake,
yeah, i took your advice and am going to hi-tech. my appt. is for saturday at 3pm. you're more then welcome to stop by! i'll definitely have to check out the car craft show, too. my brother is coming with, and i'm sure i can talk him into going. he's got a 90 mustang gt that dyno'ed 280-some hp last summer. he's also restoring a 66 sprint, so he will probably be more interested in going than i will...

the only spark table i mess with is the spark_base_table, and my datalogging matched the numbers in that table for .8 load and higher. the only fuel table i mess with is the fuel_table_stabilized_OL, and that seemed to work fine for adjusting fuel during my test runs according to the datalogs. should i be messing w/the other tables? is it necessary?

andy,
thanks for the reply and good words! i think all the work i'll be doing will be on the laptop. i told brian (the dyno dude) that i should be able to do the tuning myself. it's only $100 if you tune yourself. if i can do 7 or 8 runs in an hour, i shouldn't need much help tuning!

 

final5-0

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Apr 6, 2003

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Jul 12, 2004

#11

• Jul 12, 2004

• #11

Hey Greg

Good luck at the dyno!

I found the most power at 12.5 to 1 (my wb not their wb) for the A/F ratio and had 36 degrees total spark but did not take the time to play around with the spark as my dyno session was just kind of a baseline type of thing. I do suspect a bit more spark might make more power but the thought is not backed up with hard data.

The Stabilized Open Loop fuel table is the correct one to tweec for our strategy of pcm's. I only change the two top rows or two highest load rows on the fuel table.

If you are getting more spark than you think you should OR the values are not the same from run to run when you look at your datalogs, you might want to kill the borderline & mbt spark tables and see it things start to fly right.

Jake told me those guys know how to use the Tweecer so you most likely are in good hands for your tune.

Looking forward to your results!

Later
Grady

 

G

greg@berkeley

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Jul 13, 2004

#12

• Jul 13, 2004

• #12

thanks grady. my plan now is to do a few pulls with varied timing, pinpointing the best advance, then varying the a/f ratio between 12.5 and 13.5 over a few runs. i can't wait!

 

zenboy99

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Jul 13, 2004

#13

• Jul 13, 2004

• #13

What do you mean by maxing out the spark table with the Tweecer?

Just for kicks, my car liked a 13.1:1 A/F ratio the best. I lost 6rwhp at 13.5:1, and lost 4rwhp with 12.7:1, I'm also running 34 degrees total timing with a JMS chip

 

GTJake

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Jul 13, 2004

#14

• Jul 13, 2004

• #14

I have my A/F set at 13:1 also. Did you do any datalogging yet Greg? What is your max spark advance? I have no idea why mine is up at 42*, but I'm not going to fix what isn't broken.

You should think about coming down to the cities early Saturday and go the the Car Craft show. There is over 5,000 cars there. Many sweet late modles and older muscle cars. It runs Fri-Sun. I'll probably be down there Friday and Saturday.

Jake

 

G

greg@berkeley

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Jul 13, 2004

#15

• Jul 13, 2004

• #15

i "maxed" my spark advance to 34 degrees from 2500 rpm and up. that was the higest i could go without having to worry about pinging ever. that was the number in my spark_base_table, and that's the number that shows up during datalogging. also, i tried to use the global spark adder, but it didn't seem to have an effect on open loop conditions according to the datalogs.

i would like to come down early saturday, but my brother works third shift (11pm-7am) so i doubt i will be able to wake him up early enough to get there before the dyno appt. it's about 3 hours from here to the twin cities. we'll probably stop by after the dyno. is there a website for the event? i didn't see it on carcraft.com .