a month or so a go honda tuning did an article about swaping the gears fom an rsx type s into a si trany dose any one have any opinion on weather its a good idea or not and weather there is any place in tuscon or pheonix that will do it

 

The first person I heard do this was Nikos, a member here.

It sounded to me like it was a good project for somebody who could get the gears cheaply, and who had a lot of time on his hands and was mechanically inclined.

It can definitely be done, but if you want somebody else to do it for you it will be prohibitively expensive unless somebody owes you a huge favour.

I honestly think that if you want six speeds, it would be cheaper for you to just put in an RSX Type S transmission.

This starts a whole 'nother thought process, though.

The USDM RSX had a long axle ratio until 2005. Beginning in the 2005 model year, the RSX was delivered with the ITR/CTR axle ratio of 4.7...but your USDM EP3 already <u>has</u> that axle ratio.

Knowing all this, that it's going to be expensive and that you already have the quicker axle ratio, makes me wonder if this whole six gear thing is worth the money.

I'm just about to put an LSD in my USDM EP3, but I am keeping the five speed and the OEM quicker axle ratio.

Just seems to make the most sense to me!

 

thank you for your insight the si im trying to buy when i get back to the states is a 2002 with 11000 miles on it with that low of mileage im trying to figue out what i should swap and what i should leave to get the best power

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Yodastien &raquo;</TD></TR><TR><TD CLASS="quote">thank you for your insight the si im trying to buy when i get back to the states is a 2002 with 11000 miles on it with that low of mileage im trying to figue out what i should swap and what i should leave to get the best power</TD></TR></TABLE>

IMHO, the problems's not in the gearing. The gearing's just fine, both the five speed and the axle ratio.

You might want to consider a cheap OEM Honda Torsen axle from a DC5 ITR.

The EP3 Si sells very cheaply, but you can get in over your head very quickly if you're adding power to it. You might want to consider contacting B18Cxr (Jack Harris) about what modern turbo applications might be appropriate to your use.

There is <u>one</u> guy making (regrind) cams for more power in the K20A3 but you are going to have to think about what computer you want to use and what exhaust, to get the most power out of it.

The most popular power enhancing modification to the EP3 is a K20A2 motor, of course. You could mate it to your OEM transmission and not have to change anything else. I think you can even use the same computer that would have come on the Type S from which the motor originally came.

But anyway...you probably want to get the car and drive it for a while before you decide what you want to change.

 

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

IMHO, the problems's not in the gearing. The gearing's just fine, both the five speed and the axle ratio.

You might want to consider a cheap OEM Honda Torsen axle from a DC5 ITR.

The EP3 Si sells very cheaply, but you can get in over your head very quickly if you're adding power to it. You might want to consider contacting B18Cxr (Jack Harris) about what modern turbo applications might be appropriate to your use.

There is <u>one</u> guy making (regrind) cams for more power in the K20A3 but you are going to have to think about what computer you want to use and what exhaust, to get the most power out of it.

The most popular power enhancing modification to the EP3 is a K20A2 motor, of course. You could mate it to your OEM transmission and not have to change anything else. I think you can even use the same computer that would have come on the Type S from which the motor originally came.

But anyway...you probably want to get the car and drive it for a while before you decide what you want to change.</TD></TR></TABLE>

Thinking about tranny gearing at the end of the day makes my head hurt, but if you put a k20a2 on a 5 speed tranny wouldnt it be hard to keep the vtec engage, with the larger rpm drop between gears? I am hardly an expert, it just seems like there could be big drops with only 5 gears and using the high revving engine.

 

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

Thinking about tranny gearing at the end of the day makes my head hurt, but if you put a k20a2 on a 5 speed tranny wouldnt it be hard to keep the vtec engage, with the larger rpm drop between gears? I am hardly an expert, it just seems like there could be big drops with only 5 gears and using the high revving engine.</TD></TR></TABLE>

I don't really feel I experience large RPM drops w/the five speed. The gears seem nicely spaced, and Jack Harris can certainly rip up a track with his EP3 five speed.

As for dropping out of VTEC, that really doesn't happen w/the i-VTEC K motors the way it could happen w/the older motors. (But even w/the older motors, Honda chose the gear ratios so that you could shift at redline and always stay "on the cam" [old Porsche talk]).

 

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

I don't really feel I experience large RPM drops w/the five speed. The gears seem nicely spaced, and Jack Harris can certainly rip up a track with his EP3 five speed.

As for dropping out of VTEC, that really doesn't happen w/the i-VTEC K motors the way it could happen w/the older motors. (But even w/the older motors, Honda chose the gear ratios so that you could shift at redline and always stay "on the cam" [old Porsche talk]).</TD></TR></TABLE>

I will defer to your experience George. I have not driven a car with a k20a2 or k20a, it just seemed the 6 speed tranny would keep the gearing closer so you wouldnt lose so many revs on your way up through the gears. I would also agree that Honda usually does a good job selecting tranny and engine components in package form.

 

I'd say that if you're going to go with an A2 (whether a motor swap or just a head swap), you should get the 6-speed to take advantage of how the A2 behaves.

One of the ephatch guys that did a head swap but kept the 5-speed didn't get as much speed difference as he had hoped for.

 

In playing around w/the car at work today, there seemed to be a 900 RPM drop between 3-4 and maybe 650 RPM between 4-5. This is from just observing the tach and I'm sure it's not precise.

Under maximum performance situations on the track, that would keep you on the cam.

 

I had a couple of extra hours and some thinking to do, and this thread had been on my mind...so I took the EP3 out on the track for 20 mins.

I do not feel as strongly now about my comments that you would be unwise to spend money on putting a six speed in the EP3.

That near 1000 RPM drop between 3rd and 4th would still leave you on the cam w/most conversions and builds, but it's just slightly too much of a drop. I can see why some people would want less of a drop there. I don't know if you'd actually be faster around the track, but you'd probably feel better.

 

another possible option thats a little less involved, is to swap in the 5.062 final drive, and do the itr lsd along with it as george suggested.

but ill agree that the 6spd is better matched to the road course than the stock 5 spd