It speaks volumes in some ways, but in others doesn't. I can't recall what the Astras ran on, or how many there were, but it's period like-for-like, so in a way a degree of comparabilty is expected. It's clear that if the better cars were engineering boxes onto the K-Jet, they were just forced to work with it and look for gaps in the regs which allowed them to eke more out. Usual money winning, bit of ambitiousness on the regs, bordering on cheating - goes on everywhere. But I just wanted to pull the race stuff out of the argument, because no one here is constrained by anything artificial such as regs: just constrained by time, inclination, budget, and views on what they want, for whatever whimsical reasons, each as valid as the rest.
does anyone know what AFR readings a decent 16v K-jet car should be getting? i have some readings from when i had mine on the rollers locally but it isnt a graph just a reading every 500 rpm. can post them up if it is any use? has anyone every tried these ignition systems before with K-jet cars apart from Chris on the 8v shown above?
Jamesa has a plot of CFJs fuelling at WOT posted elsewhere.. Ranges from 12:1-13.5:1 for the majority from memory-possibly even richer at certain points. Adjusted through trial & error & development by TSR no doubt. Pretty sure Ian had a brand new metering head fitted during his initial ownership Each engine is different of course but an AFR of ~13:1 must be ballpark for a good power rich mixture at WOT Chris: Was just trying to make the point that a custom ignition map alone can hopefully still reap rewards for the KJet owners amongst us who are disinclined to go down the efi route. On saying that the ignition in CFJ is stock according to jamesa makes me wonder if the stock map is all that bad &/or what that car might achieve with a proper custom setup??
I agree, it would be interesting to know how good a map could be got from a custom / piggy back ignition box. Because it's two component parts though, I have a feeling that RR time could impinge on the savings being made and / or logic for sticking with period components. If this process can be made efficient, great - non-issue. However, the play off will be the amount of control over the engine the mapper can gain from such a system, versus the mapper's willingness to work around the quirks and still deliver the best possible outcome. RR /hour will decide that. In terms of CFJ, I'm afraid there is too much secrecy which shrouded the car from the day it was built up to 9A 2-litre spec, some 6 or so years ago. That's fine, provided the car lives off the radar, and isn't unduly flaunted... Jamesa bought it in good faith, but AFAIK the full spec was not clearly established and knowledge merely incremented with time. With non-specific information about cams fitted (believed Schrick splits), metering head spec and compression + any fuelling matters + Slick 50 bits knocking around at TSR etc, objectively it is not a valid comparative reference, aside from noting the pace of the car (never in doubt). I don't think there's anything too innovative on it, but I just think it has tweaks & mods in the right areas by folk that knew exactly what was needed, and have every chance of being non-conventional. Quite how this can stilll track a decent AFR, I'd need to see the graph. AFAIK, it had no piggy back on it. I was aware it was for sale a while back and considered it.
for all the supposinly draw backs that k jet has, ok its not perfect but, its cheap, easy to fix, its perfectly usable for road driving ,reasonable economical to run, and tunable within its limit, with some great results ,just a few examples, ianb, trimsport ,grayham tsr, barny, speedo, hotgolfs old 2.1, john jones old mk2 oettinger, fthaimike ianvant, tubs who atchieved 0 to 60 in 5 seconds .all kjet and many more . i am in no rush to move over to efi , although i do agree it is the way and proberbly will one day,my personal experience with k star was a wast of time and money,..looking forward to try out my new cams same spec as ianb. and of course tweeking the trusty old k jet,..had given it a thought about running seperate spark control ,
I bought a Mk2 16v BRM car back in september 2009 for parts (the car was a rust bucket but chock full of choice options). Car was a BRM 180 car, standard looking in the bay (ie, inlet and exhaust manifolds), but running on k-star. It made 193 bhp at the last check, i have the dyno print outs. Anyway the engine is going into my car this year sometime but i have already bought megasquirt to run it on. I have a full 16v wiring loom with k-star fully wired into it if anyone is interested?
PM sent Any graphs/info on the engine spec would be great- I assume it's a 2L 180BHP conversion? Flowed head and different cams too?? Just trying to correlate as much info on kjet setups as possible...
2L, flowed and ported head, schrick cams ported inlet and exhaust manifold, stainless exhaust and also had a porsche metered head on it? Don't know much about the metered head (have all receipts from BRM for all this work and more)
Nice spec! I guess the biggest problem as Chris Eyre has pointed out is dyno time costs &, in the case of K-Star, finding someone with the software, lead & experience to tweak it effectively! Does anyone know of any tuners that still have the capacity to map it?? Seems stealth & TSR are out
thats a nice engine spec , prooven to work to , i would try it out first, bet you have a struggle to beat that with megasquirt unless you give it to toyotec.even then your gona need a fair bit of dyno time , best of luck any how
Lots of good chaps around these days. Dyno time to develop WOT performance perhaps, live time to establish proper response.
