Custom timing curve

[Thewhite]

Does someone have the stock timing curve for a banshee?

 

I got my prgrammable CDI for Zeeltronic for a RZ350 conversion and I would like to maximize my timing curve. I know a lot of people add 4 deg of timing to the entire curve, but with mu CDI I have the opportinuty to set the timing as I want.

 

I know the stock banshee timing: start at 17 deg up to 2000rpm, raise to 22 deg at 3500 rpm, but I don't know the timing curve for the remaning rpm.

 

The stock RZ350 have more timing: start at 17 deg up to 2000rpm, raise to 27 deg at 3500 rpm ramp down the about 17 deg at 9000rpm and end-up at 9deg at 10,000rpm.

 

Does someone have found the timimg curve for the banshee, about a year ago I saw a post here that saying that the timing ramp doen from 22 deg at 3500 to 9deg at 10000 rpm for the banshee. Can someone confirm this? Or have tried to sort out the timing with a degre wheel and the timing gun?

 

 

My big question is it a area on the banshee timing profile that can be raise more that 4 deg for pump gas(begining , mid portion or end portion of the curve). The 4 deg limit should be apply on a certain portion of the curve and leave some margin somewhere in the timing profile. Also how much timing I need to remove to be able to have more top end at 9000-10000 rpm.

 

Any help or suggestion are welcome

[RZBansheeMan]

I'm quite certain that the Zeel comes with a few curve pre programmed that should work

[J-Madd]

 

I think its the white one (curve 4).

 

Here's another look at it.

[AKheathen]

the timing curve you want will aslo depend on your setup, (porting/compression included) imho, curve #1 looks like the best, especially for pv'd motors. on a non pv'd it looks like you could push the compression/fuel limits

[Thewhite]

I'm quite certain that the Zeel comes with a few curve pre programmed that should work

 

That is correct

 

the Zeeltronic CDI came with 5 igition curve in the paperwork and 2 already programmed: the cruve 2 is the stock RZ350 (31K cylinder). I will base my iginition curve to this one, but I'm interet to teak it for the max possible horsepower.

 

thanks

[Thewhite]

 

I think its the white one (curve 4).

 

Here's another look at it.

 

 

I think this graph is for the banshee, do you know the source of this graph ? I will confirm the white curve tonight.

 

Thanks

[Thewhite]

the timing curve you want will aslo depend on your setup, (porting/compression included) imho, curve #1 looks like the best, especially for pv'd motors. on a non pv'd it looks like you could push the compression/fuel limits

 

AKheathen,

 

with fuel pump (91 octane) the max timing advance is 4 deg with a timing plate, do you know if the critical timing area is near the max possible RPM (9000 to 10000 rpm) or sooner in the rpm band?

 

My intend is to do a hybride curve between the stock RZ350 (31K) and +4 banshee curve. In order to get the maximum timing at low rpm up 9000 and retard a little bit to gain RPM up to 10500 rpm.

 

My set up is: 20cc dome, transfert duration 124 deg and exhaust duration 196 deg (PV fully open), my compression should be around 150-160 psi (I haven't check it since the rebuilt).

Edited December 1, 2010 by Thewhite

[J-Madd]

I think this graph is for the banshee, do you know the source of this graph ? I will confirm the white curve tonight.

 

Thanks

 

 

I don't have any references to show that this is absolutely the OEM curve. I got this from a friend on Planet Sand years a go, and have always considered it the stock curve. That's what I would program my dyna to (and add timing in the curve across the board.) As far as the other curves on my graph: I never got to try any of those. The Dyna took a dump before I even got to make a pass. Note that you can bring the timing back up in the overrev to keep making a little power that would otherwise not be there (Per Tim@Titan Racing). BUT I never got to run it like that, so I claim no responsibility for engine failure!

[texasbanshee]

Here is the page from a Yamaha service manual for the banshee. Same curve as what J-Madd gave you.

[AKheathen]

yah, that 2nd pic is the same image right out of the yamaha e-book i have. it is an older manual(pre-95), but i don't think they ever changed the curve from 87-present....... now, +4 is not really the max, it's just the most popular setting. the max timing is all relative to compression, both in ratio, and dynamic (in correlatoin to rpm) so, given you have 20cc domes, you are already close with compression. the bore size is going to make a large difference here. so, i cannot tell you really where would be best to advance/retard without knowing the following, which is still a best estimate. mainly pump fuel is unreliable, at best of times...

bore size, elevation, pipes, rpm@pv opening....i'm sure someone with more rz tuning knowledge can jump in with first-hand curve experience..

[Thewhite]

Thanks for the support, the stock top end timing is now confirmed !