Changing from K-Jet to EFI? (Cost Estimate?)

MR-D · Post by **MR-D** » Mon Dec 11, 2006 11:09 am

Hi Guys

Was thinking of changing from my rusted old K-jet system for the following reasons:

1. Fuel economy
2. Performance
3. Easier to tune
4. First step in my Turbo conversion

I think that I need the following:

1. Fuel Rail
2. Electronic injectors (what size for N/A motor?)
3. Computer (what make/ model and cost?)
4. FPR (Fuel pressure regulator?)
5. Wiring harness for the computer

What else do I need and how much am I looking at?

Thanks

B

LittleG · Post by **LittleG** » Mon Dec 11, 2006 12:45 pm

MR-D wrote:Hi Guys

Was thinking of changing from my rusted old K-jet system for the following reasons:

1. Fuel economy
2. Performance
3. Easier to tune
4. First step in my Turbo conversion

1. If its tuned decently you can get decent fuel economy out of it, getting it tuned like that is not an easy job though. And guys getting less than 400km out of a tank is the norm in many cases I have seen. I had a semi decent tune when I first did my MK2 from Kjet to EFI and I could get around 12km/l which is pretty decent IMHO. But I also had a pretty long gearbox which I think helped the cause on the freeway. But even giving it horns I would get around 8to9km/l which is not that bad IMHO.

2. Performance - Decent Kjet can make just as much power as a stand alone but if your Kjet is getting fussy you should gain some power.

3. Easier to tune? Nope I doubt it, Kjet is pretty simple system to tune by comparison IMHO and for a home modder Kjet is better.

4. NO faults here stand alone is the way to go then.

Well number of ways to do it but I guess you would like to use your current head etc so I will just tell you what I did and what you will need and use.

MR-D wrote: I think that I need the following:

1. Fuel Rail
2. Electronic injectors (what size for N/A motor?)
3. Computer (what make/ model and cost?)
4. FPR (Fuel pressure regulator?)
5. Wiring harness for the computer

What else do I need and how much am I looking at?

1. Yes fuel rail out of a RV code (I think) is what I used which is a plastic fuel rail. You should be able to use a MP9 one (steel) or even a Digifant(another plastic) one.

2. You should be able to get the injectors with the fuel rail you source. Any of the MP9 or digifant ones will do or even if you really want the very well known and much spoken of VR6 injectors

. OR if you source oter ones around 140cc will do on a N/A 8v motor.

3. Computer is a sore topic on the BB, my view is find th Tuner you will be using and get the one he is best accustomed to and uses most often because the system is only as good as the monkey tuning it. you can buy the most expensive system you can afford if its tuned **** it will run ****. I had what many regarded as a shite system but tuned right it made good power and good economy (better than some of the guys with "better" systems) but lets not start another argument over that.

My short list in alphabeticle order (just to keep everyone happy

) would Dicktator, PRS, Topfueler.

They should all be around R2000 (maybe a little more) for the base systems with wiring harness and software but some require extras which others don't, some systems are more expensive with more features etc.

4. FPR should be on the fuel rail already and will do just fine, no need to go buy more expensive adjustable ones etc

5. Wiring harness should come with the system you buy.

Other things you will need -

If you do it yourself you will need things like heat shrink, lugs, cable ties, plugs (for injectors), Orings, fuses odds and ends that all add up quickly.

You will also need to change or modify your distributer, the Kjet uses a vacume advance mehcanical dizzy. For stand alone you will need to lock the dizzy so that it does not advance and the computer can run the timing else you can source a MP9 one and use that.

Kjet does not have a TPS on the throttle body so if you get a system that will be happy to only run of MAP you can do that (I ran mine like this). Else you will need to either get an aftermarket TPS fitted to your current throttle body or you will need to make one fit on the intake like a MP9/Digifant or similar one. Thing is its not a 2 min job you basically have to pull the intake off and make adapter plates and weld the new one on there etc.

On the Kjet head you can use the stock positioning "cups" and stick the electronic injectors into the head just like the mechanical ones. You get the FAT o-rings (check the pics) that you use on the Kjet injectors and fit them to the electronic injectors and they will seal the electronic injectors in place.

Then you will need to secure the fuel rail in place, the rail I bought had brackets that I bolted into place on the head then fastened the rail to the bracket.

I also used a MP9 airbox that I forced the Kjet piping over to keep it looking "stock" which I liked and prefer to the cone that most guys use.

This is what mine looked like

LittleG · Post by **LittleG** » Mon Dec 11, 2006 12:54 pm

Sorry silly of me I noticed now your talking about a 16v.

Changes a few things then.

Fuelrail you will need to get from Topsport etc they make fuelrails for the 16v. Not sure if they come with a FPR.

Injectors will also need to be a fair bit bigger for the 16v (guys talk around 250cc IIRC)

Dizzy advice also changes since they not the same as the 8v ones but I am not 100% clued up so will rather leave that to the "experts"...

TPS is still a problem.

What would have been a good plan was to source the ABF stuff and bolt all that onto your motor IMHO. There was a whole bunch of kit for sale a little while back that would make this conversion a fair bit easier IMHO (MK1-fan) that you may want to look into.

MR-D · Post by **MR-D** » Mon Dec 11, 2006 12:57 pm

WOW, thanks for the post reply, I think that you have covered pretty much every thing for me.

I think there are a few problems related to the k-jet system:

1. Not that many tuners know them inside out and can tune to perfection.
2. The std injectors are about 17 years old and are probably a bit stuffed.
3. To replace all the worn parts in the k-jet system would prob add up to the same as going EFI.

No doubt that k-jet works 100% but mine is not and I just think EFI would be better in the long run.

I would not sell the k-jet system but rather restore it for when the car is sold, some ppl are funny about these cars and might prefer the k-jet to keep with the original design.

I would like to go the ABF route and will keep my eyes peeled for it.

Thanks again for the post.

As usual the 16v makes my life more expensive --- soem days I wonder why I didn't just make it an 8v?

LittleG · Post by **LittleG** » Mon Dec 11, 2006 1:20 pm

MR-D wrote:As usual the 16v makes my life more expensive --- soem days I wonder why I didn't just make it an 8v?

No ways, I had the 8v and stuck with it but given the option I would never even think twice about having a 16v MK2. I often drove my mates stock 1800 16v and man I loved it. That IMHO was the true legend of the MK2's

Post by **panic-mechanic** » Mon Dec 11, 2006 2:22 pm

1. Fuel economy - ROTFLMAO
3. Easier to tune - BWHAAAA AH Ahhhhahhhha a you crack me up.

MR-D · Post by **MR-D** » Tue Dec 12, 2006 3:10 pm

1. Fuel economy - ROTFLMAO
3. Easier to tune - BWHAAAA AH Ahhhhahhhha a you crack me up.

If that is not so then why don't they make mechanical fuel injection anymore?

Post by **panic-mechanic** » Tue Dec 12, 2006 11:08 pm

Install it then we'll talk again

nick · Post by **nick** » Wed Dec 13, 2006 10:08 am

MR-D wrote:
1. Fuel economy - ROTFLMAO
3. Easier to tune - BWHAAAA AH Ahhhhahhhha a you crack me up.
If that is not so then why don't they make mechanical fuel injection anymore?

having had prs2 EFI for about a year now, fuel economy isnt something I bring up all too often. it is possible to get it pretty economic but it'd require a few hours on the road with a lambda probe, a notebook and a willing friend.

easy to tune all depends on who the tuner is, you can stuff it up quite royally if you dont know what you're doing.

MR-D · Post by **MR-D** » Thu Dec 14, 2006 10:42 am

Install it then we'll talk again

You did not answer the question, why do they not use mechanical fuel injection systems anymore?

Clearly the new systems are better than the old, they may not be easy to tune if you are not experienced in tuning on a laptop with dyno and I would not even attempt to try tune either system as my knowlege on both systems is very limited.

But the point is if you find a good tuner who knows their make of EFI computer unit they should be able to get more power and better economy from the car than the old mechanical system. The electronic injectors can be controlled more accurately than the mechanical ones, with more settings for diff rpm, ambient, Air mass, load and other settings.

If you disagree then that's fine but I would like to test it out for myself.

Post by **panic-mechanic** » Thu Dec 14, 2006 1:00 pm

A factory EFI system running 2 sorts of input - in other words - Throttle position and manifold pressure or throttle position and airflow meter - fully equipped with knock sensors and running full sequential is lighter on fuel than the mechanical system - yes. They were designed becuase the law in europe and USA is getting more strict each year regarding emissions controls and there is where they excel. The factory systems spend days and years fully mapping a computer box on an egine dyno and refining it on the road. They have TONS more inteligence and parameters and map size than any aftermarket system. Locally 99% of the aftermarket systems use a single input to determine fuelling - either throttle posisiton or manifold pressure. Now if you think that you can easily get to what your k-jet gave you in consumption, smootness and easy of operation with an aftermarket EFI you are in for a HUGE HUGE surpise. Yes if you spend days on the road and you are a very competent tuner you can eventually get them to be nice and smooth and light on fuel. I have driven and owned lots of cars with aftermarket systems and spent MANY hours tuning it to get it to come close to a facotry system but there is always a little niggle here and there that is not quite right. If you think somebody is going to quickly map one for you and it is going to be light on fuel - forget it. The ONLY system in SA that uses both the MAP and TPS inputs are perfect power and just about all the tuners are too scared to use them because they are considered too complicated to set up.
But like I said. Install one - you can tell us afterwards.....
I have said it a lot of times. Don't take a good working K-jet system off thinking you are going to score big time in power and economy.

BlueIcey · Post by **BlueIcey** » Thu Dec 14, 2006 1:20 pm

panic-mechanic wrote: The ONLY system in SA that uses both the MAP and TPS inputs are perfect power and just about all the tuners are too scared to use them because they are considered too complicated to set up.

I stand under correction, but does'nt dictator allow for the use of both as well IIRC

Post by **panic-mechanic** » Thu Dec 14, 2006 1:23 pm

Not the ones I have seen. Perhaps their latest one.

Mach II · Post by **Mach II** » Thu Dec 14, 2006 1:45 pm

panic-mechanic wrote:A factory EFI system running 2 sorts of input - in other words - Throttle position and manifold pressure or throttle position and airflow meter - fully equipped with knock sensors and running full sequential is lighter on fuel than the mechanical system - yes. They were designed becuase the law in europe and USA is getting more strict each year regarding emissions controls and there is where they excel. The factory systems spend days and years fully mapping a computer box on an egine dyno and refining it on the road. They have TONS more inteligence and parameters and map size than any aftermarket system. Locally 99% of the aftermarket systems use a single input to determine fuelling - either throttle posisiton or manifold pressure. Now if you think that you can easily get to what your k-jet gave you in consumption, smootness and easy of operation with an aftermarket EFI you are in for a HUGE HUGE surpise. Yes if you spend days on the road and you are a very competent tuner you can eventually get them to be nice and smooth and light on fuel. I have driven and owned lots of cars with aftermarket systems and spent MANY hours tuning it to get it to come close to a facotry system but there is always a little niggle here and there that is not quite right. If you think somebody is going to quickly map one for you and it is going to be light on fuel - forget it. The ONLY system in SA that uses both the MAP and TPS inputs are perfect power and just about all the tuners are too scared to use them because they are considered too complicated to set up.
But like I said. Install one - you can tell us afterwards.....
I have said it a lot of times. Don't take a good working K-jet system off thinking you are going to score big time in power and economy.

Thats GREAT news!!!!!!

Seeing as i just purchased my Dicktator mngmnt system yesterday!!!

LittleG · Post by **LittleG** » Thu Dec 14, 2006 3:30 pm

panic-mechanic wrote:The factory systems spend days and years fully mapping a computer box on an egine dyno and refining it on the road.

Last figure I heard was 6 months minimum spent on a Map for Bosch systems before you would ever see one on a production computer for the road.

Now I think one of the biggest things locally is the mindset behind the tuning. What is the general perception of a good tuner? Guys just want Numbers thats the main objective. Take it in Strap it to a dyno and fuel the thing for MAX POWER WOT (WIDE OPEN THROTTLE) so the numbers show nice and strong on the dyno. Guys leave the shop with a pretty printed page with a nice number and racing anything in sight. Everyone is very happy. 3 weeks down the line and the new found power is not so exciting anymore and your cruising on the way to work in traffic and the car jerks on every gear change, doesn't start in the cold early mornings and you notice the petrol attendants know you by name you in there so often. Thne you start to realize that you spend 90% of your day at nothing near full throttle and 95% of the map is utter crap. So you go back to the tuner and you say your not happy with the car and what do they say? Oh easy bring it in for another tune we can spend a little more time on it. Oh that will be another R600

This being said the First tune I had on my MK2 was prety decent, never had cold start issues, was pretty smooth all in all and the consumption was not bad like I said 12km/L which was not bad. My brother took over and had some issues with the box and landed up having it redyno'ed (by the same guy) but this time was a really kak tune and I could not understand why my brother was complaining about fuelbills etc untill I drove it. Utter shite, jerky and very heavy on fuel.

panic-mechanic wrote:I have said it a lot of times. Don't take a good working K-jet system off thinking you are going to score big time in power and economy.

I will echo this, unless your Kjet is starting to missbehave and finding parts is becoming an issue leave it alone it does the job pretty darn well. Naturally if your going - Turbo, ITB's, Nos or similar then yes Kjet will come off second best to a stand alone.

MR-D · Post by **MR-D** » Fri Dec 15, 2006 9:37 am

Okay you have convinced me.

Well done.

Anyone know where I can get a power rorh pipe for my induction section of the k-jet?

Seen them in the UK, suppose they could be made up by a metal worker?

tauzty · Post by **tauzty** » Fri Dec 15, 2006 12:13 pm

i love my kjet way to much,ohyes is it possible to put bigger injectors on our systems,and would it help

vinnigefanie · Post by **vinnigefanie** » Fri Dec 15, 2006 12:36 pm

tauzty wrote:i love my kjet way to much,ohyes is it possible to put bigger injectors on our systems,and would it help

No, K-Jet doesn't work like EFI, EFI depends on Injector size (amount of fuel it can inject through the nozzle in a cetain giving period for instance 250cc)

Kjet on the other hand gets the amount of fuel as givin by the fuel distributor. So no matter what size injectors you fit (if you found them) they would still only produce the amount of fuel sent by the fuel distributor

Post by **panic-mechanic** » Fri Dec 15, 2006 1:29 pm

Yup - big intake pipe can be made up by any competent metal worker.

k-jetronic rule · Post by **k-jetronic rule** » Sun Dec 17, 2006 1:25 pm

hey, my efi conversion cost me R5000 but still have feul presure problems! i bught a 8v head with gasflow and portjob +spiral grind and 3 angle cut valves+272cam+intake +injectors+feul rail+tb for R1500 from a friend the dicktator was R2000 and i paid R650 for the dino the rest was bits and pisces i needed. i put on dicktator and its a lot smoother tham my old k-jet and now have allot more power! and the best part the oke that dino'd my car told me to try it for a week and if i am not satisfied with the map he will dino it again for free!

meox · Post by **meox** » Sun Dec 17, 2006 2:30 pm

Can Gotech not also run MAP and TPS together?

Maldino · Post by **Maldino** » Sun Dec 17, 2006 5:45 pm

K-jet, did you upgrade your fuel pump with regards to all the goodies with your conversion???

I know i had to, 6 bar pump and neve had any prob's

k-jetronic rule · Post by **k-jetronic rule** » Sun Dec 17, 2006 10:39 pm

i kept my origenal pump but my prob is it pusches the feul tru closed injectors wat can i do to fix it exsept bying an aftermarket regilator?

Maldino · Post by **Maldino** » Mon Dec 18, 2006 2:30 pm

You got me there... that's a Q for 222

nick · Post by **nick** » Mon Dec 18, 2006 2:34 pm

k-jetronic rule wrote:i kept my origenal pump but my prob is it pusches the feul tru closed injectors wat can i do to fix it exsept bying an aftermarket regilator?

what fuel pressure regulator are you using? 3bar?

Changing from K-Jet to EFI? (Cost Estimate?)

Changing from K-Jet to EFI? (Cost Estimate?)

Re: Changing from K-Jet to EFI? (Cost Estimate?)