Sensitive Throttle !!

[Crazy Sierra]

Hey guys

Took my zook for a quick spin yesterday after picking it up from the shop, and it’s the first to I’ve taken it off road with the GTI motor in it, what I found really annoying was trying to drive slowly over the bumpy stuff, near impossible to do because my throttle is very sensitive ...

I’m using a modified Suzuki Vitara throttle cable but I’m pretty sure the cable alone wouldn’t course this to happen ... is there some kinda adjustments I can make to the TB or just anything to lessen the sensitivity ?

Cheers

[gwagensteve]

You might have discovered that using an engine designed for high specific output and sharp throttle response in a light road car isn’t ideal in a 4wd.

Neo might have some input- he has run a GTi motor in a Sierra.

I’d confirm the pedal travel matches throttle blade travel, and other than that, your options would be to increase pedal throw (land rovers used to have incredibly long throw throttle pedals to avoid the problem you describe- they now have different pedalmapping in low and high range) or mess with the throttle wheel so it’s progressive.

Also, I drive with my throttle foot on the kick panel to stabilise it and prevent bouncing.

[Crazy Sierra]

It’s great on the road lol but yea it’s a pain in the ass off road and that’s not even in low range so I can just imagine the bunny hopping once it’s in low range with the 6:5 gears

When you say “ increases pedal throw “ you mean give the pedal more play before it actual pulls the cable correct ?

[gwagensteve]

The problem should be much reduced in low range because you’ll be going much more slowly.

No, I wasn’t suggesting more play before the cable engages, I was suggesting more pedal travel for the same amount of throttle opening- so changing the lever ratio on the pedal. Do confirm that the cable is (just) slack at idle, idle speed is correct, and that full throttle is achieved only when the pedal is fully floored. It’s possible to adjust the idle speed and cable to result in the throttle being too edgy.

However, the issue might also related to seating position, seat, ride, tyre pressures, broken/damaged transfer case mounts.... lots of other factors.

Fundamentally, you have a responsive, high performance engine and it’s always going to have sharp throttle response- much more so than the carby motor.

[neofitou]

I didnt ever end up getting the gti engine in before I had to sell up to go to Vanuatu.

but: my insights are pretty much the same as steves.

Running 6.5s with with high ratio diffs (like 4.6-5.12s) will help utilise the rev range.
The engine wants to rev, let it make useful torque and slow the car down via gearing.

You can change the ramp speed of the throttle by changing the shape of the lever so that the first half of the throw only opens 1/4 or so and the second half takes you to full throttle from there. makes it easier to control the thing at low speeds. instead of a circle its more like a spiral so it has a small diameter at the start of the throw and larger at the end, same amount of pedal travel overall but just tweeking how it is applied to the throttle.

[christover1]

Different car and different engine mod, but in my Moke I found a stronger throttle spring helped take out sensitive pedal issues, along with the other suggestions

[Crazy Sierra]

I adjusted the cable a little and it’s helped out a bit but will have to take it off road properly to really see what it needs ... still unregistered, it’s a slow process lol

[christover1]

Don't worry, I still haven't finished working on cars I no longer have lol

[Crazy Sierra]

Don't worry, I still haven't finished working on cars I no longer have lol

Hahahaha it’s the worst lol