gti to 91 sierra

[david123]

Steve,

I dunno what gearing I have on mine, never bothered to check it out as i bought her with 30s, and took her to 31s, I checked the dia, off the top of me hed can't remember, but, very small difference, mine is sweet on road, and off, nobody can catch me, except for outright speed. Even towed a 2 ton trailer at 80k in 4th.

When she goin.

[Gwagensteve]

You've done plenty of tinkering with your motor david123, but you don't know what gears are in it? Gears are the easiest, quickest and cheapest way of massively improving your car's performance.

Short of supercharging, I can't think another way of picking up 20% more torque (or 80%, or 180% depending on gears) at the wheels everywhere in the rev range as cheaply, quickly, or easily.

"Lacking bottom end" is another way of saying "gears too tall"

Steve.

[david123]

Mate, never thought about it because the speedo so close to accurate.

Spoz when I get back ill have to lift a wheel n do a calc.

Can't see how diff gears can make up for poorly designed gearbox ratios tho. The two hard to slam gears, 3rd and 5th have a small rev change, the others are quite steep.

Another thing to put in my hed, a fairly heavily worked big block has wonderful low down grunt, I lovem, still sortof comparing the revs needed for suzi against the from idle off power of a big block. 8 liters in a 2 tonner against 1.3 in a 1 tonner

[badger]

Your not talking about a big 6 cylinder turbo diesel or a big block v8 engine with torque off idle here, there literally are ride on mowers with more power out there. GEARING IS EVERYTHING with a over tyred 4 cylinder 4wd. change your gearing first if its still too slow then look into power increases
there are so many cheap gearing options with a zook too, there is atleast 20 different transfer gear options at about 500US, rock hopper series gears for about 750 or you could mess round with rocklobster set ups, then there is the option of aftermarket diff gears for again about 500US or using 2 vitara front diffs

all of these options will make more performance / dollar improvements than just about anything and will add reliability to your car not remove it

[Gwagensteve]

If you lower all the gears, you lower the load on the motor and the car will accelerate harder.

so when the car's lugging, it's lugging against less load, so it will pull harder.
all 5 gears are packed in to less possible road speed, so the road speed change from one gear to the next is lets say, 20% less.

You really have to trust me about this, but the car will pull much harder and feel like all the gears are closer together once it's geared right.

to check the experiment - put stock sized tyres back on it - it will feel like it's got a turbo on it.

Steve.

[lay80n]

Steve,

I dunno what gearing I have on mine, never bothered to check it out as i bought her with 30s, and took her to 31s, I checked the dia, off the top of me hed can't remember, but, very small difference, mine is sweet on road, and off, nobody can catch me, except for outright speed. Even towed a 2 ton trailer at 80k in 4th.

When she goin.

If the car has standard gearing, and the speedo is untouched, then it should not be anywhere near acurate with 30's on it. You might have bought it with 30's on it, but when it was designed and rolled out of the factory it had 26's on it. So as steve said, you have added 19% to the diamiter of the tyre, and done nothing to correct the gearing back to standard. Now you are blaming the gearbox ratios for its performance.
From FSM -
1st - 3.365:1
2nd - 1.947:1
3rd - 1.423:1
4th - 1.00:1
5th - 0.795:1

You can see the big gap between 1st and 2nd. Not having corrected the gears is just going to make that gap millions of times worse. With 31s your looking at 50 indicated = to 60 true road speed. 30's are not much different. Even with a worked motor, if your gearing is out its going to feel like carp still.

Layto....

[david123]

Thanks for the gearing info, yes there is a big gap tween 1st n 2nd hey.

I will check the gears, at the mo pretty busy.

With regard to gearing, like I sed earlier, I asumed by the fact the speedo is very close that the person who put 30s on her must have changed diff ratios, or else how could the speedo be so close, askin as it stumps me.

If she needs new diffs, I will also a get locker for the rear, what about axles, while she is apart should I upgrade the axles, or just hang in there, soon she will be getn a 1.6 or 1.75ltr, me motor is using oil, no leaks, so time to upgrade.

[lay80n]

Thanks for the gearing info, yes there is a big gap tween 1st n 2nd hey.

I will check the gears, at the mo pretty busy.

With regard to gearing, like I sed earlier, I asumed by the fact the speedo is very close that the person who put 30s on her must have changed diff ratios, or else how could the speedo be so close, askin as it stumps me.

If she needs new diffs, I will also a get locker for the rear, what about axles, while she is apart should I upgrade the axles, or just hang in there, soon she will be getn a 1.6 or 1.75ltr, me motor is using oil, no leaks, so time to upgrade.

Look at transfer options too. Most gear sets offer a reduction in high and low so you can correct for your larger tyres onroad with an 18% or so reduction, and get a 180% or so reduction in low as well for crawl.

Layto....

[Gwagensteve]

It's just possible the previous owner put 4.65 diffs from a vitara in it, that would correct 31's gearing (and speedo) on road, but that's pretty unlikely. 4.6 diff gears are not that common.

It's also possible the previous owner tweaked the speedo to read right.

You need a tacho and a GPS - if you're pulling about 3500 rpm @ 100km/h, you're car has been regeared. If you're spinning 2850, it's hasn't been and your gearings up the creek, hence the big gap.

Remember too you really need lower gearing than just correcting for stock because your claws will take much more power to turn than stock offroad. At speed, horsepower can correct this, but off the line it can't.

Steve.

[david123]

It's just


It's also possible the previous owner tweaked the speedo to read right.

You need a tacho and a GPS - if you're pulling about 3500 rpm @ 100km/h, you're car has been regeared. If you're spinning 2850, it's hasn't been and your gearings up the creek, hence the big gap.

Remember too you really need lower gearing than just correcting for stock because your claws will take much more power to turn than stock offroad. At speed, horsepower can correct this, but off the line it can't.

Steve.

Doh. wake up australia, Ive dun this on me holdens, der.

Its a stupid little plastic cog that costs about $5. Slip the speedo cable out of the gearbox, with pliers pull old drive out, insert new, replace speedo cable, total time, 10mins.

When I have the tires pumped up to highway pressures, and she is warmed up n running sweet, 2nd take off is ok, and in the sand, 5psi, spinning the wheels is easily dun (2wd, very seldom put her into 4wd, no challenge, also major show off, mates cannot do in 4wd what suzi duz in 2wd)

[Gwagensteve]

Except you can't change the speedo cog in sierras - the tweaking I refer to involves playing with spring tension to get the speedo reading right - but it will only be right for one speed.

Steve.

[GRPABT1]

(2wd, very seldom put her into 4wd, no challenge, also major show off, mates cannot do in 4wd what suzi duz in 2wd)

I really really don't understand this mentality.

[david123]

At 5 psi. if I go into 4wd, she goes everywhere, serious ded set easy.

Sand is my medium, and, with a vehicle that goes anywhere, what challenge is that, nun at all, she will do easily in 2wd what others cannot do in 4wd, I have a hard time now getn people to take me on, if I go in 4wd, no one will play.

Where others leave a 8-10" deep track, mine leaves tread marks, she is excellent, built with all my knowledge for sand, what fun is there without a challenge in life, the only way others play, is is I stay in 2wd.

Winnin ain't everything, but it sure beats the shit outa cummin second.

I love seeing 100 series tojos and the like, bogged to the diffs, and cruzin up to them in 2wd, askin if they want a tow. They look at my beat up lil rat, turn their nose up n say, yea, an what do you think you are gunna do. I get out the car, an with great pride say, well, I'll put me free wheeling hubs in, then bend down and let them see me puttin the hubs in, smile my cheekiest smile n say, coz you are really bogged, and I might need 4wd to get you out.

The look on peoples faces as they realise that they are bogged to the diffs in 4wd, and a dented, crappy heap of shit that has left basicly no marks has just pulled up, and proven that they are in 2wd, is beyond words to describe the embarasement they have.

Thats is why I love my lil suzi. unbeateble.

Sorry you cannot understand this.

[zoook]

i tend to agree with layto and steve, from a man who spent a lot of time on stockton beach in soft sand at 8-10 psi that a stock geared sierra on 31s drives like crap...revs bog down on hills hard and needed fanned clutch, drop a gear etc etc ....not the way to drive one up a hill properly....you will spend more money on the many clutches you will change than a decent set of gears done once.

[GRPABT1]

So you're driving in 2H and wondering why your suzi is struggling?

And when are you entering tough truck?

[david123]

Sorry guys, im not explaining myself properly.

I am one who forever chases more power, there is no such thing im my mind as enuf, ever.

my toy goes very well, she beats everyone that goes against her hands down, im in 2wd, they in 4wd, the trouble is she is reving hard in 2nd, but I cannot change fast enuf from 2nd to 3rd, so its high revs in second, where I know well if I could get into 3rd quickly she has the power to do it, but its a slow change, and so, she falls off the cam.

Very seldom do I have to go back to 1st, usually only hitting razorbacks.

This 3rd no go is why I chase more power, or it seems, a lesser diff ratio, and or transfer case ratios.

i would love to go into tough truck, but its a long way from where I am, too far.

If you wanna see where I play, get onto google earth, look up coffin bay, eyre peninsula, and check the sand area, its huge, bout 20k x 10k and 99.999% of the time, im there by myself. When im home, im there most everyday.

[GRPABT1]

Alright I've heard enough.