VMS k-jet Grp-A

[Stereophile33]

Anyone know anything about the VMS management system that was used in conjuction with k-jet on the Grp-A cars?
Jonathan

[Stereophile33]

should I post this in performance instead of the engine management thread?

[Forg]

Are you asking purely out of curiosity, or is there a reason behind your question?
AFAIK it was basically an engine-management system except it didn't run fuel; it ran the water injection & the ignition timing. Very, very basic compared even to the most archaic of the current aftermarket commercial programmable systems like Electromotive & Microtech (pretty basic compared to what their opposition would've been running at the time, too ... pretty amazing that the cars were competitive, but I guess K-Jet's inefficiency c/f EFI doesn't come to the fore in racing conditions).

[Stereophile33]

so kjet still just handled fuel? If that is the case, then why are other people not able to take advantage of how VMS modified kjet to produce 400 HP?

If it is just standard kjet then what did they do to get 440 hp?
Jonathan

[rayj777]

It's not a standard K-Jet, it's from a Mercedes Sl series 500, 560 and modified to flow different volumes of fuel for different cylinders to make up for reversion back thru the exhaust. The Mercedes standard Sl series air flow meter and fuel distributor will flow a lot more fuel than the Volvo K-Jet, the 560 SL being the best, but it is a downdraft air flow sensor and KE Jetronic so quite a bit of mods are in order. The Volvo B-21ET flows better also, though not like the Merc. The 0-438-100-093 fuel dist, flows 15% better than the B21FT but does not have a frequency valve (no O2 sensor)

[linuxman51]

mainly cause at the end of the day you're still fighting k-jet and its oddities.

[Forg]

The only reason they used K-Jet of any description was 'cos the Group A rules said they had to ... so they basically grabbed the biggest & juiciest 'version' of it that they could. Considering how much fart-arsing around is involved to get something like that going, with so much custom stuff involved, it's easier just to use EFI - something they would have done if they were allowed.

[Neil Peart]

mainly cause at the end of the day you're still fighting k-jet and its oddities.

blah! K-jet is great....

K-jet is good i guess, MSnS can have its many nightmares too..but MS is always on top.

[linuxman51]

The only reason they used K-Jet of any description was 'cos the Group A rules said they had to ... so they basically grabbed the biggest & juiciest 'version' of it that they could. Considering how much fart-arsing around is involved to get something like that going, with so much custom stuff involved, it's easier just to use EFI - something they would have done if they were allowed.


or if theyd run the 700 series group-a car instead of that lightweight 200 series **** ;)

[Forg]

*nods*
:)

[Mind you, it says a lot for how important weight is over smart engine management etc ... although maybe they didn't have a 2.0-2.1 litre 760T at the time?]

[JohnLane]

Lets all be straight with each other......
In all it's various flavors K-Jet is utter sh*t compared with any semi-current programmable system. K-Jet was MADE TO WORK in the Gp-A goodies. This certainly does not make K-Jet an ideal or even good choice.

Get programmable and set it up right.

JL