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Posted

Hello!


After my latest track shenanigans I had a good look at my telemetry logger.


It turns out that although I've hacked a whopping 11 seconds off my lap, my top speed was around 4mph down on last time. :-(


I piddled around with the carbs between track days and the arsecheek dynamometer told me that it was running smoother with no stumbles or hesitation. I'd lowered the float level 1mm and hoiked up the needles 1.1mm to account for removing the clean air system. Post track day autopsy tells me that it might be slightly on the lean side as the plugs are a lightish grey rather than mid grey. I'm waiting on a dyno run to get some proper data on this also.


I've run a quick compression test (cold) and the cylinders are all bang in the middle of the range (~12 bar if I remember right) with max 0.5bar difference between highest and lowest.


I've checked the valves which were slightly on the tight side which I am currently sorting but this should have remained constant between days.


The only other thing that's niggling my brain is the coils, they've always been a bit jippy - even after I lopped a bit off of the leads. They're also a bit out of range on the tester. They could well be the originals so I'm entertaining the idea of splashing out for some new ones. My realistic options are pattern replacements at £80ish or dynatek coils and leads which will set me back around £175.


I've not had any experience of dynatek stuff - all the reviews I've seen tell me that they're pretty good compared to shagged out coils but I don't know how much better they would actually be than new ones...


I'd be interested if anyone has any experience of uprated coils and if you have any recommendations (especially if they are made in the UK!).


Cheers,

Fro

Posted

I'd only go for uprated ignition components if the compression ratio was increased or the engine was turbo/super charged. The standard system on many modern vehicles is more than adequate for fairly high levels of tune, when it's in good condition of course.


I'd doubt you'd see any noticeable gains using the dynatek stuff.

Posted

:stupid:


the only thing I would do is make sure you are getting 12v+ at the coils


this can make a huge difference if your wiring is shite and not supplying the correct voltage

Posted

Very good points chaps - didn't think of that! The shims should be with me today so I'll test the voltage this eve.


I double checked the coils and the primary readings were a little high but only 0.6 Ohm over spec so probably not that bad...


What do you reckon if the voltage is a bit low? Straight from the battery via a relay using the OEM feed as a trigger?

Posted

I don't know the wiring on your bike Fro.....but doesn't the firing pulse to the coils come from the cdi/ecu? .....and does it not have ignitor sticks instead of coils?....dunno what was fitted to that bike.... :?

Posted

It's positive live to the coils with a trigger from the ECU.


Turns out I'm losing 1.4v at the coils so I'll rig something up for it next week.

Posted

yeah live straight from the battery via a relay


use the power from one of the old coil feeds to power the relay leave the other live dangling free


the tigger is via the earth so you can use the same power feed through one relay then split it to the two :D

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