Might Have Different Gear Ratios Need Help.

[jasont82]

hey guys

after my dismal efforts at heathcote i decided to look in to my shit times. spoke to my mechanic who said i might have different gearing. by the 400m mark i was just hitting red line in 3rd. where as most were hitting red line in 4th. which explains my poor 95 mile an hour. he said to find out what other people are getting in their gears.

ive got the following.

30km in 1st @ 3550rpm

80km in 2nd @ 5250rpm

80km in 3rd @ 3550rpm

100km in 4th @ 3450rpm.

can someone find out what revs there at in these gears at these speeds?

cheers

[jasont82]

or how bout how fast are you going if you red line 2nd gear? think im only doing 80.

[bazr33]

i think i might have the same thing happening in my car

i had a auto to manual conversion done

but i think the gear ratios are different to my auto box

Im hitting 3100 doing 100kms, just feels a tad high on the highway

and is probably why my times are fairly standard aswell.

Who would be the best ppl to talk to im brisbane to have a look at this

Also its not helpin my fuel economy

Would like to know, ppl with a series 1 r33 what revs are you hitting doing 100

[dezz]

3100rpm seems to high for 100 in 5th....

jason, PM me your Vin number and i'll put it in FAST for you...see if it comes back with anything out of the ordinary.

[jasont82]

hey baz

yeah thats what my mechanic suggested. that maybe it had been converted from auto to manual. think the gear ratios are different.

[bazr33]

thought so

might have to look into it a bit more and see how go about changin

my car is just bloody annoying on the highway

like everyone elses car is doin like 2000rpm 0 2500rpm

[Paradizzle]

Well jason i did a wuick test for ya tonight... results are as follows:

30 in 1st: around 3850

80 in 3rd: around 3750

dont know if that helps mate... let us knwo how u go.

[dezz]

your RPM is definitely higher than his

I'll check mine tomorrow

[jasont82]

cheers mark

thanks for doin that mate. looks like my gears may be different then. your further in the rev range at both speeds so your getting to the end of each gear quicker explains why i cant get to 4th.

if anyone else can check theres out that would be good.

[dezz]

Checked mine quickly today...only did the 80 in 3rd, and the revs were about exactly the same as Mark's...3750ish

[ctjet]

do you have an aftermarket diff?

[mad082]

the only ones i know off the top of my head are at 100kmh i'm doing a bit over 2500rpm, at full noise in 2nd is about 100kmh.

and in 4th i'm hitting the 180kmh limiter (done during dyno run) at about 6250.

Edited October 12, 2006 by mad082

[Cubes]

Jason.. What sort of power are you putting out?

To be passing the line at the end of third gear something is wrong. Not the gearing but lack of power.

[dezz]

he's got around 190rwkw, maybe slightly over, but still under 200rwkw...

[Cubes]

PFC?

Might just be granny shifting.

Doubt it.. Somethings wrong.. power not getting to the wheels if your not clicking 4th and getting up close to 100mph ts.

[mad082]

i just did some calculations, and going off your speed vs rpm you be getting about the right sort of speeds out of each gear.

max speed in-

1st = 59kmh

2nd = 106kmh

3rd = 157kmh

4th = 201kmh

[dezz]

Don't quote me, but i THINK he's running a wolf3d

[Cubes]

So end of this is correct then.

The little old RB20 at around 7200rpm used to see 145km/h in third.

Quite a difference in gear ratios.

[mad082]

i'd say possible causes are really bad launch, holding gears too long and granny shifting.

[rb26s13]

car is a s13 silvia

rb26 8300rpm limiter

R33 rb25det box

CA18 silvia diff(not sure which ratio)(almost dead)

70-first

120-second

180-third

245/255-forth

gearing is hell long.. im just changing into 4th about 50m from the finish line