K-Jet Turbo info

**Oneofthegreats** · 30-11-2009, 05:09 PM

As there is still some discussion about K-Jet fuel system's I thought I'd add this back

I think it's more of case that not many people actually know how it work's or know to make it work properly so they knock it, just like when the rotary was first introduced!

With the right combination of part's, anyone can build a turbo or any FI system that's capable of out powering a number of car's going around, even in a VW & still maintain reliability, streetability & as good a fuel economy as any other high powered car (providing you stay off the loud pedal)

It's just not a pretty system!

I came across one bloke in particular who originally built a car in 1983 using a 1.6L with turbo K-Jet making 325hp & ran a 13.24 @ 124 mph. Remember the year 1983! It could have gone faster, but the turbo & setup was built for autocross.

I only know of one maybe 2 car's on here that's gone that fast & this bloke was doing it when I was 4!

This same bloke also built a 1.8L in 1991 using the so-called crappy & useless K-Jet fuel system & tuned it to a 425hp@6200 & 390ft/lb@5700 that's 546nm!

This same car ran as fast as 11.79@119 mph in 1991! I still haven't seen a FWD VW in Oz get anywhere near that time & this was in 91!

Both of these car's were street car's too & I'm pretty sure the drag rubber back then wasn't that crash hot, especially for FWD car's!

This man was a pioneer no doubt & had made 350+hp on 2 motor's using stock CIS!

People doubted him to, but his comeback was simple.

If RUF can make 650+hp on K-Jet, why the hell can't I!

This was his last effort that I know of

**Oneofthegreats** · 30-11-2009, 05:09 PM

I'll keep it short & simple, but it's all about fuel pressure's & flow.

I'm not talking about the turbo requirement's or cyl. head requirement's as this is another topic all together.

Just the fuel system.

It's just like matching a EFI fuel flow requirement's for a ideal power figure.

You work out how much power you would like to make/produce.

Then you mix & match the part's from various vehicle's, set up's & component's capable of meeting those requirement's.

eg. 5cc for every hp is a base standard

Say you want to make say 400hp+ with a 4cyl

Ideally you would like to have 500-550cc per cyl. under the set control pressure of a base control pressure + boost pressure, using a boost sensitive warm up reg.

For interest sake the pioneer (above) was running 120psi system pressure!

You also don't want to run your fuel system at 100% either, cause that can be dangerous & make leaning out easy & very risky. That's why places like to run at 80% to take in different condition eg. altitude & weather etc. It's a safe guard more so.
For the 400hp requirement, I'd be chasing the 550cc figure's!

Then using dyno tuning you keep an eye on the A/F mixture's & adjust the CO%, A/F accordingly, adjusting the system pressure & control pressure to maintain the ideal A/F.
Driving on the road is more ideal using a high quality wide band A/F guage like a microtech or autronic, as it's real world scenario's. A worth while item is also the latest in car wide band A/F meter's from FAST or Innovatemotorsports.

Seen both in action & are awesome piece's of gear. I personally own a Innovate Motorsports Wide band & love it! Couldn't have done my build without it.

My tuning setup

Happily idling away at 14.5-.14.9:2

Fitted the LC-1 in the rain tray. The oxy. sensor lead isn't long enough to reach into the car

The timing is a simple affair of either using an old twin port vac. advance canister & modifying it to pull the required amount of timing eg. 1 degree for every pound is boost or use a boost retarding controller such as a MDS 6AL BTM (as fitted to my car) which does the same thing ,but with CDI (massive spark) I choose the boost retard as I was going over 10psi to 15psi. Initially on 10psi only, I had no problems with running the reversed dizzy advance setup & drove smooth as. Heaps better & smoother than on 15psi too!

I ran my first stock dizzy on the 10psi setup under full vacuum advance from the intake manifold port. So I'd set my ignition timing up at approx 10BTDC with full vac advance dailed in. So when I cracked the throttle, it would retard the ignition timing the set amount of vacuum advance. Say you have 10degrees of vac advance. it would retard this as soon as you sniffed the throttle.

I can go further into this with technical calculation's & such, but really can't be bothered sitting here for hour's on end working everything out.

I hope all of this makes some sense.

If there is enough interest in K-Jet turbo stuff, I can copy over my build thread from vortex. It has more than enough pics & info for just about anyone to tackle this sort of setup.