VK EFI 6 - modification

[kurtbarker]

Hey guyz. I have a 1984 EFI VK [straight 6] and I want to do some mods to it, but don't know where to start.

As far as i've read on here i'd be looking a CAI, Exhaust, Air Filters, Cam, Diff

Now call me new to all this but I don't know what those things are :my:

So could you please tell me about each, what they do and how they would affect my car. Different 'types' of each, if they're are different types, and the differences.

Would it be easy to install? Or would I need someone to do it for me?

If you could give me approximate prices for these, and how to go about getting them [where from, etc]. I'm not on an ultra tight budget or anything, so don't be scared to put some expensive things in there, but cheap things are also nice.

Besides these is there anything else I should be looking at?

And PLEASE don't suggest I get a rb20, rb30, etc etc, i'm not asking about an engine conversion :ranting:

Thanks

 

[vkberlina]

Ok here we go

Your biggest gains will be in your head, you need to get the 202 to breath there is no point installing a hot cam if you cant get the air & fuel in or exhaust gasses out.

Head work consists of making the ports large enough to suit the valves installed in the head along with the cam shafts requirements. From memory with some combustion chamber work you can fit 1.94 inlet and 1.6 exhaust valves in there.
Just remember not only do you need volumn of air/fuel going in you also need velocity to you can get as much air & fuel in, in the shortest period of time.
You also need to choose valve springs to suit the camshaft you will be using.

Camshaft this controls when and for how long and how far valves will open and close. Depending on the RPM range you want to drive at, the type of driving you will be doing will all come into picking the right camshaft. Also what head you have. If you will be running a high lift cam it is recommended you purchase a set of roller rockers also.

Once you have your head & cam your next bottle neck with be exhaust, the extractors on the EFI 202s were pretty good the only modification I did to mine when I had my 202 was to cut off the collector and replace with a bigger one, I ended up using 2 1/4" or 2 1/2" (cant remember) I think the original was 2"
With the enlarged ports on the head you need to reshape both the intake manifold and extractors to match the ports on the head this is called port matching.

CAI. The VKs did have quite a good genuine CAI system although these are getting harder to come by now. Air filter wise oyu wont get a real benifit from somethink like a K & N panel filter unless you have alot of work done to the engine or your chasing every HP you can get out of the thing.

Bottom end.
In doing the work to the top end gains can be made in the bottom end as well.
Light weight racing pistons, lightened & balenced rods will all help. Get the bottom end balenced thats everything, harmonic balencer, crank, rods & pistons, flywheel the lot.

Once you have the engine built the next short coming will be in the ignition system & injection system, you will need higher flow injectors, after market EFI computer, after market ignition good leads. Check out the Haltec E6x which can do both Ignition & Injection, use 3 coil packs and get rid of the dizzy.


Diff wise either a 25spline or 28 spline borgwarner LSD would be the way to go and pick a ration to match your gearbox and what driving you will be doing.
If your doing Highway KMs you want a taller gear ratio than if your doing heaps of city Kms or wanting a quick take off.
Also depending on the gearbox your running will depend on what ratio you pick.

If your running a 5 speed and want a good highway car I would consider 3.08 or 3.45:1
If your chasing faster takeoffs you could go higher.

There are other things you can do such as flywheel lightening.

cheers
Scott