Gear ratios.

[V8_nutter]

If you meant ET by calculation.. it'll 11.4xxxx.. car weighting in at 990+kgs... it's not a lightweight drag machines like you see in sepang.

But the reality is different.. it's making low 13's, which suggest some issues with the gearing (or the driver/owner) :P

The top speed for each gear is as shown.. second gear hits 109kmh at 8K, and if rev to 9K, the torque curve start to taper drastically already.. nothing bigger injectors and a retune can't fix. (I hope :P)

Like yours, the power taper off just a little later than 8K, but it's a B20 short stroke, and running high rpms is rather risky, although it's highly possible, since it does have forged internals.

I'll consider what you said.. I don't really fancy doing drags since I feel my reaction time is worse than a tortoise, but I guess I'll have to try it out and think of what you said, and perhaps try some new ratios...

Thanks.. I appreciate your help. PM your contact number, and I'll treat you for makan when I head down.

My power didn't taper off at 8000rpm, it did that only on 4th gear. For the 1st till 3rd gear it peaked at 9500rpm. Shiro if you plan to get 12sec with a stock body it's quite hard, base on your chassis & short peak of power (8000rpm) it will make it harder to get the correct ratios.

Power on the paper and dyno is use for knowledge only, there's a lot of factor involve. Once you get into speed, horsepower will lessen because of wind factor, so 1st gear horsepower and 4th gear horsepower is difference (get what i mean ). Instead of calculating speed & et with a software, better find an open road and do the hand clocking, this is for the real world.

 

[shiroitenshi]

Thanks.. that what my next step is..

I know about the drag factor.. That rear bumper is one big air pocket, furthermore, we're trying to do it with a slightly lightened chassis.

As for the short peak power, currently the idea is trying to can put enough gap between the gears so it can run a high 12 with 8K rpm, which means with higher RPMs on the 1st and 2nd, it can achieve higher trap speed in less time... hopefully a high 11. (after all, I doubt the owner wants to race it.. he's just in it for the novelty of having an 11 sec car, I think.)

 

[V8_nutter]

Just my curiosity,,,shiro what tyres he using to get 11 or 12 sec ?

 

[hattech-v]

if not mistaken, u must use full drag slick to get that 11-12 sec..

 

[shiroitenshi]

if not mistaken, u must use full drag slick to get that 11-12 sec..

Yup.. check that.

 

[evoX2]

bring back dinosaur age thread. For 300m or 400m drag, 4.4fd or 4.7fd is better?

previously mentioned, by reaching 2nd gear with speed 120km is good. But with my 1.9 2nd gear ratio also can reach that speed but during drag kena buang far away when i'm in 2nd gear.

 

[hattech-v]

aiyo... depen on the ratio oso... n always practice... hehe

 

[akuma]

hattech-v,
always practise can also lead 2 sum PAINFUL experience wor?!hahahaha

 

[shiroitenshi]

bring back dinosaur age thread. For 300m or 400m drag, 4.4fd or 4.7fd is better?

previously mentioned, by reaching 2nd gear with speed 120km is good. But with my 1.9 2nd gear ratio also can reach that speed but during drag kena buang far away when i'm in 2nd gear.

Actually since you obviously don't understand yet, I give this simple analogy.

All gear ratios and FD can be used, it's just that the engine can either be:

a) has not enough torque for the gears.
b) too much torque for the gears.

It's about getting the balance right so that you don't get either

a)which will make your car have slow acceleration, or;
b) lots of power and wheelspin, but not much acceleration because of wheelspin.

non B20 setups are usually not very good torque makers, so we play with high rpm, which is more suited to FDs from 4.6-4.9, with the proper gear ratios to suit.

It's better if you have tried something like a 4.9 or 4.7FD with the stock gearing and comparing to the stock 4.4. Then you'd have a clear idea what the FD does.

 

[akuma]

shiro,
do u know d ratios 4 YS1 gbox?its running in 4.4FD...m looking 2 hybrid d 3rd gear frm DC2 GSR into it..waddaya think?

 

[shiroitenshi]

Hmm.. let me check and get back to you.

YS-1 FD is 4.2 stock, isn't it?

I can give you est. speed possible at xxx rpm for that gear, but whether your engine has enough power to pull it or not is something you have to find out yourself.

 

[akuma]

shiro,
no no..YS1=4.4FD...Y1=4.2FD
thx

 

[hattech-v]

akuma, gbox with YRV code what fd?

 

[shiroitenshi]

shiro,
do u know d ratios 4 YS1 gbox?its running in 4.4FD...m looking 2 hybrid d 3rd gear frm DC2 GSR into it..waddaya think?

Hmm.. just looked at the ratios and all I could say is this.

Stock 3rd is about 140kmh at 8000rpm on 195/55/15 tires.
With the GSR 1.36, you can go up to 150kmh at 8000rpm on those same tires.

So with the GSR 1.36 (3rd gear), you need better torque to use them compared to the stock ratio.

(Do note minor deviations of tire pressure/expansion not accounted for)

Unless you're not running the stock 4.4FD, but higher like 4.6 and up, with 9/9.5K revcut, I think it may be doable, and can get some improvement on it. But then, maybe you're doing this because your car is a torque monster, I dunno la.

But with the stock FD4.4.. I think the stock ori one better. (O_o)

As a user of the Y21 g/box, 3rd gear is same with the YS1, at 1.458.. And for me, it takes a seriously long time to get to get to 8K, from the rev drop point of 6K shifting from 2nd to 3rd, with a 4.4 FD. If I rev it higher up to 9.5K, I should be able to cross the finish line in 3rd at 150-160kmh trap speed at redline. That is, if I have enough torque (relatively, lighter chassis need less) at that rev range to actually pull it off. :P

Let me get a sample run of the auxbox and show you this.

 

[Grex_R]

look for fei lo vtec lah ask his opinion

 

[akuma]

hattech-v,
YRV gbox?hurh?i tot YRV is a Daihatsu model?i duno ler..

shiro,
thx alot...

 

[evoX2]

akuma want to change to 1.9 and 1.36? u need to change the 1st gear as well. if u want those ratio i know who will have it. haha

 

[evoX2]

useful info on the gear ratio, final drive comparison.

http://www.team-integra.net/forum/display_topic_threads.asp?ForumID=10&TopicID=38223&PageMsg=Viewing+Common+Topic

 

[hattech-v]

anyone looking for kaaz 5.0?

 

[akuma]

evoX2,
nope..m only looking 2 chg d 3rd gear ratio..can it b done?changing just d 3rd n maintain d rest?anyway,y u say i need 2 chg 1st as well?n who has it?ur location so far....dun tell me sumwhr in ur hometown ar?hehehe