LS B16A Gear Ratio

[tseesinngwailo]

Hey All,

I have a JDM B16A and box in my 91 LS DA9

it goes like a rocket but I find it seems a very low ratio gearset, on the freeway I am doing 3500rpm at 100klm/h and even around 60 zones it feels like I can use 5th gear too.

I read a writeup on a DC2R Integra and it said that the car did 3500rpm at 100klm/h, does this mean I have the same gearset or should mine be a different one? Anyone else done a conversion and found the same, I would have preferred a little less zip for better cruising on freeways, 2000rpm would have been nicer.


Thanks
Chris

[tinkerbell]

you have similar to ITR

1st 3.25
2nd 2.052
3rd 1.416
4th 1.103
5th 0.906

and a final drive of 4.4

whereas Type R has:

1st 3.23
2nd 2.105
3rd 1.458
4th 1.034
5th 0.787

and FD of 4.785

the reason teh JDM B16A's have such low gear ratios is to take advantage of the high end power and lack of low end torque...

also - see how the ITR 5th gear ratio is lower than the B16A but the Final drive ratio makes it almost the same RPM at the same km/h...

[tinkerbell]

(but overall - the ITR has lower total ratios - except for 5th gear which is almost the same total ratio, whcih was doen to achieve a good cruise RPM in 5th but keeping 1-4 ratios nice and tight)

[FR33K]

yeh the high revving on the freeway is pretty annoying but it picks up faster when u put ur foot down.. it was weird at first and i used to always go to change to my non existent 6th gear lol (even still do it now)..

but if u put ur LS box back on it will go like shit

[ewendc2r]

lol -- Know what you are saying about the '6th Gear' .. :P When I first got my Teg I was like, now there should be another gear here? :P hah

[PHASE2]

yeh i got the same gear box in mine it sits around 3900 at 110 its kinda annoying sometimes when you try to go for 6th and there is not another gear there lol oh well i do agree alot that it has more pick up though!!

[krovikan]

Yea, my XSI is the same... i found that on long trips it saves alot of fuel to drive at 100kph as apposed to 110kph... the little difference in speed ment that i was able to make an extra 130-200 kms (driving constant 100kph in a straight line)

[tseesinngwailo]

(but overall - the ITR has lower total ratios - except for 5th gear which is almost the same total ratio, whcih was doen to achieve a good cruise RPM in 5th but keeping 1-4 ratios nice and tight) thanks for that, I wont be changing anything but now I know, Cheers

[tseesinngwailo]

Would love to do some long trips but my wife says that the baby cant handle the harder ride in my car, I said there is a $1000 bucks of seats to keep her comfortable, but she wont budge haha, main reason for asking I with current petrol pricing, want just a bit more economy, maybe will have to disable the Vtec haha Once again this forum has been excellent for helping out cheers All,

[FR33K]

i drove to all the way to melbourne in vtec haha still got over 600kms per tank !!
dont disable anything lol

[LO_N_SXC]

Good thing I ran into this thread, I'm actually getting my self a B16A gearbox from a friends wrecked DA, and for a real good price too! I will picking it up in two weeks I shall let you guys know how it goes, I hope the car feels faster than it does now also I hope its in good condition since mine is about to crunch its self to bits!

[string]

Good thing I ran into this thread, I'm actually getting my self a B16A gearbox from a friends wrecked DA, and for a real good price too! I will picking it up in two weeks I shall let you guys know how it goes, I hope the car feels faster than it does now also I hope its in good condition since mine is about to crunch its self to bits!
On a B18A; I hope not for your sake.

[FR33K]

it will be a bit quicker but i hope you dont plan on cruising on any freeways lol
your gonna be revving near redline doin 120km/hr (bit of exaggeration but close enough :P)

[LO_N_SXC]

On a B18A; I hope not for your sake.
Nah mate on a B18B which is in way better condition than any B18A you may find in a DA9 Teg.

Oh btw I ussually travel to work on the hwy so there is a lot of stop n go driving from my place all the way to the city so I guess the close ratios will come in handy. ;)

Trust me I know how bad it can get with close ratios, my old datsun 180B has Twin Carbies and runing a 4spd close ratio box dont help with fuel consumption, 100km/h @ 5000rpm! now thats close ratio.........

[string]

Nah mate on a B18B which is in way better condition than any B18A you may find in a DA9 Teg.

Oh btw I ussually travel to work on the hwy so there is a lot of stop n go driving from my place all the way to the city so I guess the close ratios will come in handy. ;)

Trust me I know how bad it can get with close ratios, my old datsun 180B has Twin Carbies and runing a 4spd close ratio box dont help with fuel consumption, 100km/h @ 5000rpm! now thats close ratio.........
No that is a short gear ratio; Closeness requires comparasin between two gears, of which the single 5th gear is not.

B18B = B18A, and the condition of the engine isn't going to affect how the gearbox allows it to perform. Either way, you'll be revving way higher for no real good, changing gears too often. You may be marginally faster in first gear until 5000rpm, but is that worth the extra hassles?

Just out of curiosity, how do you know it's in 'better condition' and how do you define that?

Fuel consumption isn't dependant on RPM, you will notice a negligible difference if you drive in the same manner.

How will close ratio's help with stop and go... A stock B18A in a DA integra still has plenty of wheel torque to keep up with traffic; I certainly doubt your going for it for better daily driving...

Having said the above, have you considered grabbing a VTEC head and maybe revving a little higher? You'll certainly feel the benefits of shorter gears if you do this.

[LO_N_SXC]

No that is a short gear ratio; Closeness requires comparasin between two gears, of which the single 5th gear is not.

B18B = B18A, and the condition of the engine isn't going to affect how the gearbox allows it to perform. Either way, you'll be revving way higher for no real good, changing gears too often. You may be marginally faster in first gear until 5000rpm, but is that worth the extra hassles?

Just out of curiosity, how do you know it's in 'better condition' and how do you define that?

Fuel consumption isn't dependant on RPM, you will notice a negligible difference if you drive in the same manner.

How will close ratio's help with stop and go... A stock B18A in a DA integra still has plenty of wheel torque to keep up with traffic; I certainly doubt your going for it for better daily driving...

Having said the above, have you considered grabbing a VTEC head and maybe revving a little higher? You'll certainly feel the benefits of shorter gears if you do this.
HA HA HA HA lol with all respect but its funny how people mis read what is said on these forums, I dont want to stir the pot but I shall take this opportunity to clarify what I posted:

B18B better condition than a B18A, well of course you tell me what is in better condition an egine with 250,000+ kms (which is the norm for many B18As) or the same engine with 7 or so yrs more development and with half the kms?????? by 7yrs I mean a B18A built in early 89 to a B18B built in late 96.

I know the condition dont afect the ratios of the box, I also know that both engines would run at he same revs in any gear with the B16A box (close ratios) but then again you wouldnt want a old worn B18A reving more than ussual.

Fuel consumption aint dependant on RPMs?????

wtf plz look at any V8 lets say a 5litre, 5litre you say? yes heck but that would suck petrol up like a motha! well if you were to drive one at 100km/h in 5th gear you will notice that the revs will be set on 2000rpm to 2500rpm, why? well its a 5litre! more engine capacity means more fuel and air is induced into the engine for combustion, changing the ratios thus means less rpms less petrol can be used, and yes it all comes down to the ratios, now compare this to your YS1 tranny which is what I have on my car sme senario 100km/h but this time 3000rpm or just above that, then again it is a lower capacity engine compared to the big V8 but requires more fuel and Air to reach the engines eficiency doe to the rpm.
So that means that the B18A/B will be reving those extra 1000 revolutions which require more petrol to do so.
Try crusing on the freeway at a higher speed like 10kms more and you will see that your petrol wont last the same amount of kms than if you were travelling at 100km/h.

So yes fuel consumption is dependant on RPMs and on gear ratios, and yes I'm aware that my B18B will use up more fuel but then again I dont drive it daily.

Daily driver? dude I aint loaded with cash so no I dont drive my car every day to the city, petrol aint cheap you know? and yes close ratios = faster acceleration, meaning that once you take off the lights you wont have to keep ut with traffic but get ahead of it ;)

Vtec head aye???? Nah I doubt it mang, too expensive for just an extra 10 - 20hp not worth my troubles, I rather make the most of the Torque of my B18B which is more than a B16A and slighty more than a B18C, Dont believe me then do a Search! ;)

[JasonGilholme]

The only reason large capacity 8 cylinder engines rev lower at 100/110km per hour is because they don't need such a short gear set to get them moving. They've got the extra capacity to easily spin such a large gear set. Thats why a b16 revs to 8200 and a v8 will go to 5500.

Also, fuel consumption has been discussed many times. Frome what i've learnt from those threads it all depends on how you use your throttle. Not neccesarily when you change but how quickly/slowly you accelerate. The slower the better apparently.

Can't wait to see the different with this box. It will be interesting to see.

jase

[LO_N_SXC]

Well I pick up the box in two weeks time then I still need a new clutch and I also need to get the flywheel machined, once its all done I shall do a review for you guys.

[string]

You havn't proved anything with the nonsense you just posted.

Volume of air the cylinders before compression is constant, but pressure is not. This is modulated by a throttle, and is the reason that cars can idle, instead of bouncing off a rev-limiter.

A set ammount of fuel will generally give the same ammount of power when burned, regardless of the engine (most engines these days are of similar enough efficiency to compare this).

Doing the same task, requires the same ammount of power, no matter what is driving it. If two engines are producing similar powers, they are generally using similar fuel volumes.

In the case of a big v8; You may have worse fuel economy due to heavier car weight (which is evened out on the highway cycle due to wind resistance being the force to overcome); More internal resistance from twice the number of cylinders; Heavier drive-train to rotate (intertial losses) and so on. Also, they may generally have richer tuning.

Your engine with the shorter geared gearbox, will only be applying more internal resistances, that is all.

As I have said a million times in this life allready; Fuel economy is based on how fast you accelerate, not rpm. Please argue some more with me though, it's funny.

How will "closer" gears give you faster acceleration? Simply stating that they will does not prove it so. A physically sound reason would be nice. I will agree you will be faster. But you'd probably be faster if you spent the money from the gearbox on an intake or something instead.

How much has it costed you anyway.. You could setup an LS/VTEC for very cheaply. You are opting for a short ratio'd gearbox, why do you care for 1-2Nm of torque difference (of which probably wouldn't exist, since B18C is less capacity than the B18A/B in the first place, LS/VTEC is the same capactiy as the B18A). You'll have considerably more wheel torque than the B16A, but you will still be dropping off in power at stock redline, negating the strong point of short gearing.

Also; You'll find that 7rs of development has given you what, 2hp more? No need to re-phrase what you've said, why not compare a 92-93 B18A to your magical condition B18B? There are plenty of them running round in fantastic condition. Age is not the only factor determining the health of a motor.

[ZeForce]

Volume of air the cylinders before compression is constant, but pressure is not. .

Actually, the volume of air and fuel in the cylinder is not constant. Each cam profile has a maximum volumetric efficiency, percentage of the volume of fuel and air that actually enters the cylinder compared to the actual capacity of the cylinder, which occurs at a certain rpm range. The further away the engine revs from its peak efficiency rpm range, the less fuel and air actually enters the cylinder. This is why honda developed their VTEC system to use 2 cam profiles with the maximum volumetric efficiency of each cam occuring at different rpms, ~3500rpm and ~7000rpm for the B16a, resulting in a much wider useable powerband....

[string]

Woow looks like we have a new ProEcu. Arguing for argument sakes.

"Volume of air the cylinders before compression is constant" ???

"I will agree you will be faster." Enough said!
Good job. I argue with people who try to be smart on this forum, but actually just spit out garbage. I try to present people with information but the majority of this forum does not accept any technical elements. This gearbox will be faster in low-mid first gear, but over-all, by a small ammount. If $500 is worth 0.1 second quater mile (if that) so be it. If you interpret my "I will agree you will be faster" as defeat on my behalf, then go for your life, because I'd rather spend $500 on a set of traction bars, or an LSD and get my 60 foot time down giving me maybe 0.3 second 1/4 or more for the same money.



out of context garbage

Thats nice. How do you explain things to people... ONE STEP AT A TIME. If you want to play the out of context game so be it. The cam profile doesn't alone describe the volumetric efficiency curve, it will change based on any physical element of the head/intake causing change in the flow of air. E.g. port sizing (vtec heads have larger ports causing lower low rpm intake velocity for less v.e. thus less torque). Next?

[ZeForce]

:thumbsup:

[LO_N_SXC]

**QBALL EDIT: Stick to topic guys!!**

Oh back on topic; I'm getting the box probably this weekend but wont be installing it till I get the new clutch, so I will take some pics of the process and will keep yall posted on how much better the car feels.

Cheers!

Alex ;)

[LO_N_SXC]

Guys it looks like the gearbox wont be hapening since the person selling the box to me just upped the price and wont budge on the price, might have to just get a YS1 from the wreckers?