Was out mapping my new ZT build and was experiencing det immediately after changing gear when reapplying the throttle (this is after changing just before the limiter).
So to cure this I've had to remove about 12deg of advance from the normal high rpm cruise area of the table, see below.



I've not had this before and can normally run around the high 30's to very low 40's in this area of the table.
I just wondered if this is normal for a ZT or perhaps there is something I'm missing?

All input welcome, thanks!

 

that's not normal at all, i run plenty of advance around that area.
what is the trigger offset on the crank set to?
if that's too little in TS/MT then the advance will be raised and will det easier than you would think.
my offset is 80 degrees and no problems with det that i can tell, certainly nothing off boost. saying that i'm just in the process of sorting my map out due to turbo downgrade, not altered the timing at all though.

 

Trigger settings are correct for the 36-1 setup with Tooth #1 @ 80deg BTDC yes so the advance is correct.
It's as the boost builds immediately after the gear change that it happens, so not totally off boost if you see what I mean?! lol

 

could it be just a misfire, check the plugs.
i used FRS ones brand spanking and had a detting effect, altered map which took loads of power out and then went about checking compression only to find a crack down one of the plugs.
replaced with ITV27's and had no problems since.

 

Definitely det Sean so not that.

 

don't forget the Zetec needs far less advance than the CVH

 

just an idea with the plugs, but timing shouldn't need pulling back that much, i've seen a lot of spark maps that run into the 40's off load and around 30 degrees approaching atmospheric pressure.
what fuel is it on?
what are EGT's like also, could be needing more fuel and altered timing to cool things down a little.

 

So would you say this is normal for a ZT then Rick?
Yeah always worth a look, it's on 95RON and I have no idea of EGT's as I dont have a gauge.

 

Karlos, that table is gash.

You have the same timing at 100% load as you do at 20%. 28 is probably still too much at 100% and it's too little at 20% No wonder you were getting det at 40 degrees lol

Rick

 

lol Thanks Rick!
Yeah i've used my CVH map as a base and so just pulled the timing back when it was detonating and then came on here to ask about it.
So what sort of figures would you suggest Rick, 30 tapering down to what 25? Perhaps post a pick of a ZT advance table for me?
As Sean says I've also seen quite a few OEM maps with advance in the 40's at those area's of the table (300zx and 200sx for example) and of course my old CVH, didnt realise a ZT wouldnt like it.
Thanks for your help!

 

no wonder its detting! high comp and cheap shit fuel wont help.

 

28 degrees at 100% is not far off what it's going to like, so if it's happy there I'd say that's a reasonable figure. You can taper towards the mid-high 30's as load decreases.

Rick

 

Thanks Rick, much appreciated mate!

 

Hellloooo!

Why don't you scale your map better. If that is really load in % down the side rather than kpa is there no way you can increase the resolution? You running alpha n, speed density or some sort of blend?

I can see if i can dig out some of the maps i did for Cols ZT way back. GT30 turbo but similar CR so off boost stuff should be ok to use as a starter.

I seem to remember having figures for WOT on boost of 13/14 degrees around max tourque rising to 18/19 degrees as the revs increased and the cylinder filling dropped off. This bit will be different for your engine / turbo combo.

I also agree, get some super in there you tight arse!

 

I think its a reasonable idea to map on 95 first, at least you have a map for it then if you ever need to run it.

WTF is going on at 1100rpm though, where you suddently introduce a load of extra timing as load goes up from 70-80?
Or is that just a case of you havent done that bit yet?

 

Ps

You do know you can just highlight a section of cells and use the blend tool to get it to interpolate between the first and last? (red and blue thing top right) Then you can fine tune from there.

 

Hi Doug!
It's not load in % it is KPA! I could rescale it yes, but it was my old CVH map and as I was running 30psi so it needed to be how it is! lol
No the resolution cant be increased thats it mate.
I'm using speed density.
The reason I'm using 95 is because it's cheaper and will limit my final BHP... I'm still on an IB5 gearbox so anywhere near 300bhp and it's going to fall apart in no time!! lol
No point squeezing every last BHP out of it on 99 when I dont need it... Yet!
Yes I know that thanks Chip, as I said above I used my CVH map as a base and have only spent 45 mins just getting it safe to drive by pulling timing out to get rid of any det and adding fuel where needed, I'm not going to spend too much time on it as I have a new inlet coming soon and will have to do it all again!

This is what I started with so you can see I've just made some quick changes to make it safe, the old CVH map...

 

Why does your CVH map do that weird thing with the ignition at 1100rpm as well mate?

 

IIRC It used to stumble a little on first throttle opening and I added more advance and fuel in that area to cure it... Don't think I could get it smooth just using the TPS based AE, is it an unusual thing to have done?

 

Yes its unusual that as load increases you add a whole load more ignition.

Doesnt mean its wrong as such though, I do it quite often (setting low load cells to less ignition) on the cells used during idle, but just not that far up before it goes back to normal.
But haivng now seen your comment that the load is KPA, that probably IS where it comes off idle?

 

Yes thats exactly where it comes off idle as you first open the throttle, I dont know why TS labels the KPA axis as load % but yes it is KPA.

 

Of course you can re scale. You wont be running 30 psi on the zetec with those pistons (stock?) and that turbo so re scale the whole thing for 1.5 bar to start with. Same with your fuel map.

You are right about the inlet. Chances are you might have to pull a load of fuel out and whack some more advance in. lol

Make sure you log you AFRs prior too and after fitting. Proof is in the pudding and all that. I know the fabricator is a genius tuning god but only the cold hard numbers will prove if he has gone in the right direction or not.

Anyway, i seem to have doubled my last years post count in this thread!

 

hahahahahahaha Yes I will log the AFR's before and after for a B2B comparison!!

I can rescale yes, but I just havent as it was a quick session to get it drivable!
Anyway how do you know I won't be running 30psi?! ....... But no your right I won't! lol
Yes it's on stock ST pistons and rods so max bhp is around 350, I will probably leave the scaling because who knows what I might do in the future... A set of rods and pistons and a GT30 would mean rescaling the whole thing again!!