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How to tune timing without dyno
Posted: Sun Mar 22, 2009 11:57 pm
by ckretvix
Looking to learn how to do timing as best as possible without a dyno. I've heard that you can go to the track, and add timing until trap speed no longer increases, then back off a little (like a dyno), or just read the plugs after a run/pull. But isnt shutting the car off after doing a run really bad for the turbo as your killing the oil supply when its been loaded hard?
Posted: Mon Mar 23, 2009 10:55 am
by Synoptic
shut off the engine, but kepp the car in gear, this way the oil pump will still provide pressure.
Re: How to tune timing without dyno
Posted: Mon Mar 23, 2009 3:25 pm
by 98vtec
ckretvix wrote:Looking to learn how to do timing as best as possible without a dyno. I've heard that you can go to the track, and add timing until trap speed no longer increases, then back off a little (like a dyno), or just read the plugs after a run/pull. But isnt shutting the car off after doing a run really bad for the turbo as your killing the oil supply when its been loaded hard?
i would not advice adding timing until the mph doesnt increase. You may run into a few cells that dont want as much timing as the other (shouldnt once you reach MBT) but still thats kinda iffy. If you do it that way, keep a strong eye on the plugs after every run.
Posted: Mon Mar 23, 2009 3:36 pm
by ckretvix
Im asking cause Im not sure the process people use at the track.
Posted: Mon Mar 23, 2009 3:55 pm
by 98vtec
from my experience, i dyno tuned and then fine tuned at the track.
Posted: Mon Mar 23, 2009 7:32 pm
by ckretvix
When you tune on the dyno, does mbt usually come before detonation?
Posted: Mon Mar 23, 2009 8:16 pm
by 98vtec
not necessarily. Depends. You can detonate anywhere and the most prone areas for detonation are high load and low rpm. That puts the most strain on the engine and requires careful tuning for high compression and supercharged applications. The timing curve to MBT and what the engine whats in order to not detonate is going to differ on a case by case basis.
Posted: Tue Mar 24, 2009 8:18 am
by combz
im surprised more people aren't trying to help you. anyways, i would suggest a good det monitoring system. There are really expensive ones out there now, or i'm sure you have seem some DIY ones that work quite well. 1.Do research, find an approximate value based on setups that are quite similar to yours for timing numbers and start on the very low side of those. 2.Tune with det mon device on. 3. don't go crazy adding a bunch of timing in all at once, in all ranges..if you want to do it right it takes a while. Add timing in certain rpm region first...listen for det at that point...if there is none bump it up again..but again you cant go nuts, because it takes a fine tuned ear to distinguish between detonation and other engine noises. 4.check plugs often thats all i can suggest, comments are welcome, and i realize this is not ideal, but may be better than shooting in the dark
Posted: Tue Mar 24, 2009 10:24 am
by ckretvix
Well right now Im running a stock B18b at 12psi with about 18.5deg of timing at redline (.75 retard per lb). I feel like I could put a little more advance in after looking (like 1 deg) at some tuned maps in rom dumps. The car is going to the dyno this saturday with a group for a dyno day so I'll see what it puts down, but I wont have time to fine tune anything.
Posted: Sat Apr 04, 2009 3:04 am
by Bindegal
Cost of dyno session with time for adjustments: $100? Cost of blown engine: $2000? Do the math

If you don´t have the cash to spend on the dyno, you sure as h___ don´t have the cash to rebuild that engine. /Allan
Posted: Sat Apr 04, 2009 8:24 am
by Garrett
Bindegal wrote:Cost of dyno session with time for adjustments: $100? Cost of blown engine: $2000? /Allan

Posted: Sat Apr 04, 2009 7:32 pm
by Piv
Garrett wrote:Bindegal wrote:Cost of dyno session with time for adjustments: $100? Cost of blown engine: $2000? /Allan

No more to say ! Once you use a dyno for tuning, you'll never be back only on track but always do both!