The Quest For Speed!!

[rob83ke70]

Hey

We currently have a ke55 road/race car, it has a 280/286 degree camshaft, twin 1.5" su carburettors, 4-2-1 extractors and 2" exhaust system with 2.25" muffler at the rear, lightened flywheel, electronic regraphed ignition, everything is balanced, and we have thermo fan fitted. This engine however is coming out to go into a ke30 race car to replace the very very rusty ke55 body. This car is to be set up primarily for dirt events, and it will be on historic plates, so a) we do not have to stress too much about drivability/noise/road type issues and b) everything must be from the period of the car.

 

On the to do list thus far: modified exhaust for better flow and less noise, try to keep heat in exhaust and cold air in induction charge (fit heat shields and wrapping etc), fix a few oil leaks (from sump gasket) and better ventilate the crankcase. Body will have roll cage fitted, no carpet, trim, or deadener, lightweight seats and harnesses fitted. Battery will be mounted in boot, extra space will be used for catch tank and to allow greater flow of cold air into carburettors.

 

Now, I was wondering, is anybody here using a different gearset from the standard item? I was wondering if it was worth fitting a t50 gearbox and a set of straight cut dog engagement gears with closer ratios... or even a set of shallower helical cut gears with syncros with closer ratios? I would imagine that it is possible to get gear sets much easier for a t50 than a k50, which would be the reason for the conversion. I'm curious to know how much heavier a t50 gearbox is as well, the world wide web of questionable information says a t50 weights somewhere around 27kg, unsure of what the K box weighs though. Obviously I'm trying to keep weight to a bare minimum as it is a K engine, and its all about power to weight ratio.

 

The shallower the angle of the gears, the less power is lost in transmission, which would be a good thing :dance: I'm not overly worried about the noise of the straight cut gears either.

 

I'm assuming I'd be better off going with a jap U series diff (don't want to put a heavier unit in, as I'm only running a k engine) due to the ratios being much easier to change, and obviously some mixing and matching to get the diff ratio right. Thinking a 4.11 might be the go on 185/60r14 tyres, but this depends upon the gear set too.

 

I'm open to suggestions for other ideas to get the car lighter or grab every last little HP out of that engine :y:

 

Robert.

[coln72]

With a Jap diff there are 4.5, 4.3, 4.2, 4.1 diffs available and on dirt I think I broke two locked diffs in 6 or 7 years of competition. This was behind a cammed and carbed 5k.

 

If you have not already done so-

 

Thinner oil in the engine, gearbox and diff will help reduce friction. Used to run a mix of gearbox oil and auto trans fluid in my gearbox.

 

Break out the alloy and remake various brackets etc. Remove every wire that is not necessary for the car to work. Scrape all of the sound deadener off. Drill various bits and pieces and removed bits that you don't need/allowed to/can get past the scruitineers.

 

In an extreem case, a KE25 was reduced to approx 650kg by doing the above and a few other things :dance:

[rob83ke70]

I was thinking staight cut gears would be an interesting development....... all depends on finances, which may also have some bearing on whether a K50 or a T50 gearbox is used...

 

I'm definitely going to be going over the car and doing all that, every little bit of weight counts! I'm sure too that with cold air going into the carburettors, (maybe velocity stacks fitted too) and hot air leaving via a revised exhaust, I can get a little bit more power out of it!

 

Robert.

[coln72]

Try Albion(?) Offroad Gear in Ballarat Vic. They used to make custom gearsets.

[snot35]

I think you're referring to Albins off road. I think the best bang for buck would be to get a T50 and the TRD gearset. They are still around. I think it works out to be around $2000-$2300 and you'd obviously need to source a K-T bell housing, which would be the hard part. I think the place in NZ that has them is called Palmside or similar. I can dig it out if you like. For road rally I'd stick with the 2.6 first rather than that ultra close.

 

I'm not sure there would be that much difference between straight cut or helical, but that's probably for a different post :dance:

 

Depending on class you could start thinking about glass panels?

Edited December 29, 2009 by snot35

[SLO-030]

Hey

We currently have a ke55 road/race car, it has a 280/286 degree camshaft, twin 1.5" su carburettors, 4-2-1 extractors and 2" exhaust system with 2.25" muffler at the rear, lightened flywheel, electronic regraphed ignition, everything is balanced, and we have thermo fan fitted.

Robert.

 

Hey Rob,

 

A little off topic but where did you source the Tri-Y K series Extractors?

 

CHEERS

Ryan

[rob83ke70]

came with the car...... closest I've seen yet to equal length primaries and equal length secondaries too!!

 

Robert.

[altezzaclub]

Copy it and make half a dozen!