Hi guys Having seen the great results obtained from guys running optimised ABF setups on Megasquirt, it has got me thinking about us humble k jet users... I'm just wondering what (if any) the options are for reworking the ignition timing on a valver aside from k-star? I know the common trend is to go Megasquirt- but I dont have the time/patience to do it. Furthermore I'm quite happy that the fuelling is ok and can be adjusted- albeit crudeley via the WUR. Knowing there are K Jet cars out there that still make great power with this setup (CFJ- jamesa/ianb White mk2 springs to mind) I think improvements are wholly possible retaining the oem fuelling. CFJ runs a 7800rpm ECU crystal, 268/276 Schricks & ~13degs static advance. Not sure if it runs any ignition control though. Could the extra advance be due to the ignition map being "stretched"? In any case that car makes very very strong power Historically the limiting factor on most 2L converted valvers seems to be the amount of static ignition advance they can take before pinking occurs. The stock KR map is obviously far from perfect as its possible to run plenty more than the oem 6degs adv with the WUR suitably adjusted....my own car runs ~10ish without pinking I know k star works by the dizzy being fully advanced and the k star unit is programmed to pull timing to varying degrees at 500rpm increments- thus preventing pinking at vulnerable points but maximising the advance elsewhere. Problem is does anyone still map/deal with them? Have seen them on the classifieds from time to time, but pointless if nobody can map them nowadays... Are there any other options for an ignition only setup- unichip perhaps? Any views/experiences/advice gratefully received... Cheers Chris
Pug 205 GTI dizzy setup has it's own mech and vacuum advance in the dizzy. The weights and springs can be tweaked to optimise the advance curve. Or a Megajolt ignition system is a possibility. This can be fully mappable and utilise MAP or TPS.
If you can I would use Megasquirt to control just the spark, the costs are not far of the price of Megajolt anyway. Then if you did want to change to EFI over Kjet you could do easily without the expense of buying a new ECU.
Never realised it was possible to do ignition only with Megasquirt Does this make it much more simple in terms of hardware changes?? Il have to look into it further. Never been a fan of home-brewed stuff to now as it seems riddled with pitfalls and niggles- some of the recent results have been excellent though!
Chris, Good luck with the investigations, afraid that I`ve no insights to offer on the ignition system other than it was standard as far as I knew. I ran it on BP or Shell Super and only ever noticed slight pinking on one or two occasions (Summer). When running hillclimbs & sprints I added Millers CFL Turbo Octane booster as a precaution.
I put if you can - meaning I am not sure how to do it/or if it is possible, Eddie would know the answer im sure just thought it would be a good idea for the future.
Cheers. I know from speaking to Ian that it ran ~13degs give or take weather dependant. My car runs well at 10degs- plenty of low down punch and revs to the stock 7200 cut out nicely. More advance seems to reduce the reviness at the top with no more gain low down. Might fiddle further with it...can't hear any pinking at the moment though I think a good part of running plenty of advance involves having a rich mixture courtesy of the WUR- & also keeping engine temps well in control with a fresh cooling system and external oil cooler. Oil temps are safely sub 100 on a road blast now..... I have seen talk of the ignition map being "stretched" when the rev limit is upped so this may account for CFJs extra base advance...? Having driven it a couple of times I know the engine was all top end with the cams and rev limit.. I am yet to find a 16v that runs it's best on the stock 6deg diamond anyhow- all feel flat as a fart to me beit KR or 2L variants. 8degs+ and they come alive
Very interesting stuff. Im just wondering how many k jet users have doen the "WUR MOD" and whk still does it. Id like it done on mine on a RR. My only change is 6 degrees advance but il be tweaking again when i get a timing light. Going to run standard then try at 8 and see the difference. Running on 97 ron fuel
I borrowed a fuel gauge and did it myself!!! Easy Toolkit, drill and Allen keys and away you go. Control pressure to 48psi and job done! Just follow the guide in FAQs- "setting fuel system pressure" or something similar... I really need to invest in a gauge now so I can do further tweakage..
What was the difference in drivability? power? fuel economy? I can get a gauge and give it a go saturday then!
Can't quantify it with figures- but the car felt sharper and more eager to pick up on part throttle and the MPG on the mfa improved slightly. Certainly a noticeable improvement with further tweaks do-able on a RR or using a wideband lambda to tweak AFR you'll need to reset the idle co to 2% once the WUR has been tweaked too...
Yeah i always check co from time to time. Will give it a go. I did hear of a spark controller for a k jet system which was meant to give more power. Or is that the unichip?
very interesting thread Chris, does anyone know of any companies still able to set up K-Star? i know alot of people change over and go EFI but it doesnt suit everybody. i wonder if its possible to run a megasquirt system and just use the wasted spark and see if good results can still be had using K-jet?
Stealth "did" but I believe the magic cable got lost.... C&R? I know they used to sell k-star so I'm assuming they must surely have mapped a few? Pretty sure TSR don't now though they also used to... Old technology now eh??
Ah, yeah old technology and all that, bit of a bummer... i remember asking Jim Curley at Star Performance about it about a year ago and he had the lead and disc required but said it was alot of hassle and didnt make enough money from doing it so said he woudnt take on the work of my 16v. is there many people still running K-star on there 16v's these days? Is CFJ running K-star?
It is only "riddled with niggles" when the user perhaps bites into something he cannot chew in the quest of saving a few bob. As to home brew and I very thankful. Put this DIY ECU in the right hands and you will have results as any other expensive system. KJet is OK, but could never offer the flexibilty as a full standalone system for both fuel spark and some additional functions. Remember you not mapping for just a WOT dyno test...
I dont believe CFJ is- though Ian's sparring partner round Combe (& ex TSR workshop manager) Graham runs it on his 2L valver. His and Ian's cars are very equally matched I don't suppose many people do mess with it nowadays- though I'm sure Graham could rack his brains. Id like to experiment with one if it came up for sale though...
Offsetting the dizzy on K-Jet system just offsets the entire timing map. On a KR you can offset quite far advance there would be very little knock on 98 RON fuel. Not all 16v engines require the wam-up regulator mod as some fuel quite well to the redline anyway. You will need to perform an AFR sweep on a dyno on in gear to see where the engine mixture is and if any offset to this will cause a change in torque. As the WUR is mechanical it will take a few tries to determine the best setting. Something full EFI users find easier to do.
