hey every1, i know the ep3 type civic si's and the rsx both have k-series in em, but the rsx has the 6 speed where as the si has a 5. would it be worth it to put the 6 spd in the si? and is it even possible? or am i jus smokin somethin?

 

people have been doing it, it does work. if you can get the transmission for a good price i would do it.

 

what are the benefits? wouldnt it be slower? or is the 6 spd geared pretty well?

 

The 6-speed is geared shorter than the Si's 5-speed, except that the final drive ratios are taller on the OLDER 02-04 RSX-S 6-speed gearboxes.

The current 05+ RSX-S 6-speed has the same FD as the EP3's, and its 6th gear is the same as the EP's 5th. The 06+ FG2 Si's 6-speed is just like the 05+ RSX-S's except that its 6th gear is taller (the same as the TSX's 6th).

For a while, I've had the opinion that a 6-speed on the Si's K20A3 motor wouldn't be that great, expecting that it would drop the RPM's out of the motor's upper powerband.

But, the thing is, there's not really a need to stay in the upper RPM range on the A3 motor; there's no high-rev cam profile, and no high-revving vtec changeover, so there's no bump in high-rpm power (and, thus, not nearly as much drop in power if the revs go too low).

Still, though, because of the lower redline, you'd shift more often with a 6-speed on the A3 motor than on either the RSX-S or the new Si.

Acceleration would be better than stock, yes. But, because you can't spend as much time in each gear before hitting the rev limiter, you'd have to shift sooner every time compared to a Type-S.

Put another way: The top of 2nd gear is nearly the same road speed in either the EP3 Si or the RSX Type-S.

I still think the 6-speed works best with the high-revving K20A, A2, Z1, and Z3 engines.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BarracksSi &raquo;</TD></TR><TR><TD CLASS="quote">The 6-speed is geared shorter than the Si's 5-speed, except that the final drive ratios are taller on the OLDER 02-04 RSX-S 6-speed gearboxes.

The current 05+ RSX-S 6-speed has the same FD as the EP3's, and its 6th gear is the same as the EP's 5th. The 06+ FG2 Si's 6-speed is just like the 05+ RSX-S's except that its 6th gear is taller (the same as the TSX's 6th).

For a while, I've had the opinion that a 6-speed on the Si's K20A3 motor wouldn't be that great, expecting that it would drop the RPM's out of the motor's upper powerband.

But, the thing is, there's not really a need to stay in the upper RPM range on the A3 motor; there's no high-rev cam profile, and no high-revving vtec changeover, so there's no bump in high-rpm power (and, thus, not nearly as much drop in power if the revs go too low).

Still, though, because of the lower redline, you'd shift more often with a 6-speed on the A3 motor than on either the RSX-S or the new Si.

Acceleration would be better than stock, yes. But, because you can't spend as much time in each gear before hitting the rev limiter, you'd have to shift sooner every time compared to a Type-S.

Put another way: The top of 2nd gear is nearly the same road speed in either the EP3 Si or the RSX Type-S.

I still think the 6-speed works best with the high-revving K20A, A2, Z1, and Z3 engines.</TD></TR></TABLE>

Someone dumb this down for me. I thought the high revving engines liked the six speed because there was less rpm drop between shifts due to the gears being closer together. Since the a3 makes more tourque lower it seems like the five speed would be well suited with more gear spacing and more rpm drop.

Or maybe I am just way off.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by giff74 &raquo;</TD></TR><TR><TD CLASS="quote">

Someone dumb this down for me. I thought the high revving engines liked the six speed because there was less rpm drop between shifts due to the gears being closer together. Since the a3 makes more tourque lower it seems like the five speed would be well suited with more gear spacing and more rpm drop.

Or maybe I am just way off.</TD></TR></TABLE>
Actually, you're thinking the same way I am; I just used more words.. lol

 

The RSX transmission has a LSD, though, correct? that would be worth it in IMO. Although, I suppose you could get a better LSD for cheaper than a whole RSX transmmission.

Edit: ok. I forgot. no LSDs on domestic RSXs.



Modified by Phil B at 9:37 AM 4/6/2006

 

no, dc5's do NOT have LSD's. although, some of the drivers maybe under the influence of it.

only the 06+ SI's have LSD.

 

what's LSD?

Sorry, im a noob when it comes to cars...ive been mostly just browsing the forums and not posting too much to try and learn but im still having difficulty understanding things...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eMpAtHy &raquo;</TD></TR><TR><TD CLASS="quote">no, dc5's do NOT have LSD's. although, some of the drivers maybe under the influence of it.

only the 06+ SI's have LSD.</TD></TR></TABLE>


and dc5 type-r ..... i'm almost sure of do but thats jdm

 

LSD = Limited Slip Differential. You know how the inside wheel spins like crazy when you're trying to gas out of a tight turn? That's because it has less traction, and the stock open diff just spins that wheel all it can. An LSD helps keep power going to the wheel that still has traction. Torsen (otherwise known as "helical") LSDs are "torque-sensing", and send torque to the wheel with the most grip. Clutch-type LSDs (such as Mugen, among others) lock the wheels' axles when one begins to slip.

Anyway, that's a quick 100-level course on LSDs.. lol

And, yes, the overseas DC5-R uses a helical LSD, just like the 06+ Si.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BarracksSi &raquo;</TD></TR><TR><TD CLASS="quote">
Actually, you're thinking the same way I am; I just used more words.. lol </TD></TR></TABLE>

So in reality a 6 speed wouldnt be bad for an a3 engine, it would just stay higher in the rpm range (where I think power is pretty good anyway). However an a3 with a super duper charger, k-pro with higher revs and a six speed would be a pretty tight ride.

I can imagine all that torque with "high" revving goodness. UUmmmm lots of torque, I like torque.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by giff74 &raquo;</TD></TR><TR><TD CLASS="quote">So in reality a 6 speed wouldnt be bad for an a3 engine, it would just stay higher in the rpm range (where I think power is pretty good anyway).</TD></TR></TABLE>
True, but being higher under a relatively lower rev limit (relative to a K20A/A2, that is) would mean that you'd spend less time in each gear. Doing the 2-3 shift, for example, would happen at a lower road speed than with the 5-speed tranny.

Then again, the TSX has a 6-speed transmission, but with a redline pretty close to the A3's. Its 2.4-liter motor has noticeably more torque, though.

I could probably go either way with it. For autocrossing, though, it might be awkward, seeing that the courses I've been on have gotten to the top of the stock 2nd gear -- which means that, if I had a 6-speed, I'd probably have to shift in & out of 3rd.

 

so the final verdict is...? lol im gettin so confused. so what should mix with what for the best result i guess.

 

I wouldnt do it for **** and giggles or to a stock a3 engine, there's just nothing to gain. I am wanting to add a JRSC to my a3, that would add rpm's with the k-pro. Then I think the 6 speed would be really nice to have.

 

I don't know if this is quite the same for Civics, but my Nissan Sentra Spec V (which I'm hoping to sell to buy an RSX-S) has a very "low-revving" motor (6200 RPM redline) and a 6-speed. Despite the frequent shifts, it's really nice to have 6 gears rather than 5.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by efyou &raquo;</TD></TR><TR><TD CLASS="quote">so the final verdict is...? lol im gettin so confused. so what should mix with what for the best result i guess.</TD></TR></TABLE>
Honestly, besides the cost, I'm avoiding (for now) putting in a 6-speed because it would knock me into Street Modified autocross classes.

Now if it were part of a K20A2 or K24 swap, that might be a little nicer....

 

from what I hear, using the 6 speed is just not beneficial for the EP3. If you dont plan on forced induction (turbo/supercharger), then you might consider it (though its a pricey upgrade for little return), but it doesnt do much in the way of improving power or acceleration. in fact, all other things equal, if you dont shift right, you will be slower in a 6spd since you have to shift more frequently.

if you have that kind of money to spend, why not go with headers, intake, test pipe, and exhaust. you'd be looking at a comparable cost and considerable HP gain.