How much drivetrain loss does having straight cut gears have compared to hellically cut?

 

FAR less than people make you think.

couple of percent if that IME

 

good.

 

??

 

im with chip,,,

 

You've had some expericance with Minis, what about straight cut drop gears?

How much of a difference do they make you feel to a Mini? What power level would think about fitting them? I've heard around 100BHP.......

 

I know it wont be a lot, but just wondering what the real world gains were, some places recon upto 5% which is quite a lot IMHO

 

In a mini you are lucky if you see a genuine 2bhp difference IME

Well over 100bhp should be fine on a normal box (for a while), the drop gears want swapping for SC at about 110 though normally.

 

Cheers.

I meant drop gears, not the actual 'box.

 

the box i have has straight cut gears.

 

Dave.....

Will asked: "How much drivetrain loss does having straight cut gears have compared to helical cut?"

Chip said: "FAR less than people make you think......couple of percent if that IME".

You thought: "Nice only 2% of my engine power will be lost through the mullet box"

When in actual fact, the difference in losses between helical cut and straight is only a few %.

 

Sorry, reading that question again it is very badly put

Err, how about:

What are the drivetrain losses with a straight cut kit compared to a hellically cut kit?

Working on a 4x4 figure of 35% losses for a Std 4x4 set up, would it be fair to say the straight cut box should see these dropping ( ie more power making it to the wheels) to between 33-30% loss?

 

Doug, cheers for clearing that up, that is exactly what I meant.

 

L8 ECU

bang on what i thought Doug.

but i'm i not still right.

 

yes there is less loss with straight cut than with helical, and the more power you have the less you loose. as with helical as your power increases as does the side load on the box gears hence why you see bigger hp cars lose more on crap helical boxes (well there not all crap - just compromised)

 

normal mini drop gears are good for well over 110bhp, infact they are stronger then straight cut drops,,

.....however the forces on the bearings would be massive and wouldnt last long

.. ive got straight cut drops ready to go into my mini, worth it just for the noise

 

Dave, what I meant was that the losses on a SC set are within a couple of percent of the losses of a standard set.

Ie it will NOT free up any significant amount of extra power to the wheels.

(although like Mark says, its application specific the exact amount and the more the standard setup is on its knees with the sideloading the more you can free up, its still never going to be a massive amount though)

 

Indeed, its because of the bearings that you have to replace the drops with SC ones.

 

Dunno about drivetrain loss, but I suffer hearing losses quite a bit from mine

 

 

i'm not bothered about freeing power,just loosing it.

if the loss is minimal then i'm happy.....as i did above.

 

You certainly wont LOSE power going SC isntead of Helical (well unless they are much much thicker gears) Dave, so yeah, be happy

 

you going to coombe/ going on track dave?

 

My mini box is gonna need a rebuild soon.. keeps knocking it self out of reverse

Might buy a s/c drop gear set for it..