Thanks datoman1k this confirms an a14 with a15 pistons will be right for at least 12 psi of boost for it should have 8.5 to 1 comp.

A15 has the shorter piston
30mm pin height

I cant remember which has the lowest pin height the a14 or a15 piston?

wait till he can get the car going before really yelling. no need to over do it ;)

lol

I like that advice...I'll yell at him, drop a few fake spiders in his lap and generally stress him out whilst teaching him to drive! (He's 12 in a few months)

Fortunately the motorkhanas are mostly 1st gear events with the occasional shift to 2nd.

ahh yell at him lots....hehehe

I don't even have a tach!! Sometimes i think about getting one. I'd rather have a manifold pressure gauge really. Unless it's one of those cool F1 led tachs, I want one of those.

make him help replace bent push rods and he'll learn not to miss shifts.

I think slamming the car into the wrong gear is worse than over revving in neutral, at some point the engine will get to as fast as it wants to spin and not go any faster.

A newbie is more likely to shift into the wrong gear I think, from what I see at events where kids drive. Things get hectic and they get flustered and shift badly. So yell ay him lots whil learning to drive stick so stress won't get to him as much ;)

hehe

I'm thinking of a shift light, maybe run a wire into the boy's boot too - so he gets an electric shock in his right foot when he hits the rev limit.

I'm hoping it will be pretty hard to miss a gear for him in a 4 speed...

it's "soft" in as much as as you approach the limit the car develops a miss instead of cutting completely out, so it's gentler. Down side... It's not as abrupt as you might like for teaching.

i want a widget that watches the tach and if you put the car in the wrong gear it activates a solenoid that operates the clutch and then the rev limiter brings it down. rather easy for us with hydraulic clutches. While I'm at it, hill holder unit too ;)

Cool

That makes sense, as soft rev limiter = ignition, hard rev limit = fuel.

Might be something to look at before the boy gets in the car....electronic ignition that is.

It's a function of my accel 300+ ignition box, I have it set to 6250, but it's variable every few hundred rpm.

This won't keep him from shifting from 5th into first, but it's not supposed to.

I'd worry more about missing a shift than taking the rpm too high. My engines usually get to a point where it's not worth holding the high rpm. set the limiter right around that point and teach him to stay in the good powerband.