ignition timing + full t25

[Fordy]

Right guys i'm looking for a heads up and rough idea of how much ignition retard i'm going to have to run

Ive got a brand new turbo technics t25 stage 3 turbo sat next to me n its got a .49 rear housing and i've got a standard cam and 209 aei in place atm

iirc the carb is set up 1.2main,1.7 needle, 1mm ac, stock 1st stage and 1.3 2nd stage gives me a nice 11.5-11.8 afr (please note i do track days hence running it richer) Fueling is easy for me wideband etc

Timing on the other hand with a pushrod engine and wet liners this will be fun when im used to dohc engines with nice efi management :crap:

For now i'm going to run it off the actuator pressure so i don't think i'll have to worry too much about det as my rad is leaking slightly (new rad here next week)

Just wondering when the boost goes up how much have people had to adjust the timing back to keep away from det?
So i'm prepared to adjust that far or more to keep safe on track as i'm sure going round track with det cans on wont be allowed :laugh:

[Dave Reed]

You really need a set of det cans on to mess with the timing.. Only safe way of tuning really.

[Fordy]

oh i will be using det cans just wanted a rough idea of how much others have had to retard the tdc sensor if at all

best i clean out my ears before the road test :D

[sammo_gtt]

i think it depends on how much boost you are thinking of running? to my understanding, as long as your fueling is good you can run up to around 20psi on standard comp with out having to play with the timing, thought you only had to ajust timing once you start running silly boost or run a vnt just to help stay away from the det... just my opinion and not a fact tho, im sure some1 will correct me if im totally wrong lol :)

[Fordy]

Was thinking of setting the actuator to 14psi for track work and then if required mbc valve to 18psi for normal/fun

but it if blows a hg it does me a favour as i'll have a reason to change the cam to a noice 285 :D just dont want it to blow it out on track when its a long way home on a recovery wagon :laugh:

[Brigsy]

If the compression is standard and the intercooling/fuelling is good you should be able to keep the ignition standard for 20+ psi. Get something on there to listen for det when setting up.

[TNT ANDY]

TBH Adam, if your set on this and I'm surprised that it is not standard tuning on here, if you're going to be running more than standard boost then you ought to be mappable ignition, heck even if you're running standard boost you should re-map the ignition as the original map is not very exciting. I have mentioned it b4, but TNT Ross did the ignition only using MS and set his up on a rolling road and was amazed at the benefits of tuning the ignition alone and like others have said, this really is the only way to tune properly. Whacking the boost up and hoping for the best is bodging really.

[tiff_lee]

I have often asked if megajolt would be a good alternative but have been told the dizzy is fine?

[Brigsy]

TBH Adam, if your set on this and I'm surprised that it is not standard tuning on here, if you're going to be running more than standard boost then you ought to be mappable ignition, heck even if you're running standard boost you should re-map the ignition as the original map is not very exciting. I have mentioned it b4, but TNT Ross did the ignition only using MS and set his up on a rolling road and was amazed at the benefits of tuning the ignition alone and like others have said, this really is the only way to tune properly. Whacking the boost up and hoping for the best is bodging really.

I have to disagree here, standalone ignition isn't essential on these engines unless your really pushing the power figures. It would be nice to have but its the cost, lets face it unless you can map it yourself your not getting any change out of £500 for the cheapest setup.

I and many others have ran standard ignition with no problems for many years at high boost, yes the map is far from ideal but it works. Ive been up to 1.6bar boost on my setup with no det at any rpm on track, strip etc.

With a t25 and standard cam you might aswell save your money and spend it elsewhere for better power gains. Bang for buck id rather change the cam first, it will make more power at less cost.

[GTphil]

[quote=Brigsy;250267]I have to disagree here, standalone ignition isn't essential on these engines unless your really pushing the power figures. It would be nice to have but its the cost, lets face it unless you can map it yourself your not getting any change out of £500 for the cheapest setup.

My thoughts exactly, all depends on how far you want to take it and how much you have to spend.

Think of things like the cam/turbo first as this will give you the best base should you want to take it further.

[GTphil]

As for tuning on the road I find it very hard work, keeping an eye on the boost/afr/revs and listening for det whilst going at unmentionable speeds.

A co-driver is a big help when setting up.

[Scoff]

I think Andy is probably refering to the benefits you get in midrange and spool. Totally agree that there isn't much to be had at WOT once you're up on boost. The timing curve of the Renix works OK as it is up there.

[Fordy]

Ive got 2 turbo minis running megajolt atm and tbh i think for low budget system you really cannot go wrong so i will possibly run this on my 5.

The resolution of the map is a bit pants and the software is slow to use compared to others i've used but it works fine in the end.
Just wish 1 of the minis was built better as it keeps going wrong just getting to the dyno its getting rather annoying to say the least

But im going out in the 5 tonight all geared up and hopefully i wont be coming home in a mood with a broken engine again as i've got a nice 50mm alloy rad to fit this weekend :)