EMan
 |
|
|
Can someone please tell me the "lineage" of the TSX's engine? Is it the first time this engine has been used or has it been tweaked from other engines in other Hondas? I have read on other posts that its a K24?? I am not sure what that means....can someone help me out or direct me to a link that can help out? Thanks in advance for your help!
|
VTEC_Inside
|
|
EMan wrote:
Can someone please tell me the "lineage" of the TSX's engine? Is it the first time this engine has been used or has it been tweaked from other engines in other Hondas? I have read on other posts that its a K24?? I am not sure what that means....can someone help me out or direct me to a link that can help out? Thanks in advance for your help!
|
The "K" series engine made its North American debut in the RSX (K20A2/3). I'm fairly sure about that.
There are essentially two different blocks (2.0L and 2.4L), and two different cylinder heads (Mild VTEC and Wild VTEC). I can clarify the latter if need be.
The TSX engine is the 2.4L variant with the wild VTEC cylinder head on it. I'm not sure of the full engine designation though.
Basically you have the "K" denoting the series, followed by a number representing the displacement, and lastly a variant code.
For example I'll use the RSX
Base model: K20A3
RSX-S: 2002-2004 K20A2, 2005 K20Z1
Type R: K20A
|
euro.r
|
|
|
Tsx: K24A2
|
euro.r
|
|
|
Oh and also the K24 variants are found in the CRV and the Accord I4.
|
BOOMER
|
|
|
I take it the Accord I4 has the "mild" head, or does it?
|
iivtecracerii
|
|
|
yep, the K24 in the accord, CR-V and Element have the "mild" VTEC head.
|
the rookie
|
|
|
the JDM Integra and the JDM Civic Type-R3 have the K20A (3 cam lobes on intake and exhaust cams/double valve springs on intake and exhaust/11.5:1 compression ratio) the RSX Type-S has the K20A2 (3 cam lobes on intake and exhaust cams/double valve springs on itake only/11.0:1 compression ratio) the base RSX and Civic Si have the K20A3 (2 cam lobes on intake cam, 1 on exhaust cam/9.8:1 compression ratio) the CR-v has the K24A1 (2 cam lobes on intake cam, 1 on exhaust/9.6:1 compression ratio) the TSX has the K24A2 (3 cam lobes on intake and exhaust/EGR porting/10.5:1 compression ratio) and the Element and Accord i-4 have the K24A4 (2 cam lobes on intake, 1 on exhaust/EGR porting/9.7:1 compression ratio). Hope this helps!
|
EMan
|
|
Thanks to all for your very helpful and informative responses.
One last question: Is there any other 4cyl engine in a sports sedan that can compare to the TSX's? I work with a bunch of guys who believe that any German 4cyl engine but I know that cant be true. Lastly, what do you think is the "best" 4 cyl engine out there...the S2000's?
|
VTEC_Inside
|
|
EMan wrote:
Thanks to all for your very helpful and informative responses.
One last question: Is there any other 4cyl engine in a sports sedan that can compare to the TSX's? I work with a bunch of guys who believe that any German 4cyl engine but I know that cant be true. Lastly, what do you think is the "best" 4 cyl engine out there...the S2000's?
|
I really don't think Mercedes or BMW have any 4cyls that come close at the moment.
As for the best 4cyl out there? Well it really depends on the application. Just fyi, a lot of the design elements that first appeared in the F20C (aka S2000 engine) have been incorporated into the K series.
|
BOOMER
|
|
|
I really wish AH would put the TSX engine in the RXS-S if it fits, does it? The added torque should transform the RSX if it has an LSD standard.
|
JeffX
|
|
I'm the other way about it. I think the TSX engine is a little out of character for the TSX, never mind a sport coupe.
I guess it would be interesting to see what it would be like, but I can't imagine it being nearly as fun as the current 2.0L motor in the '05 RSX. When I drove the Euro R in Japan, I preferred the revvy K20A to my K24. I'm hoping that Hondata will soon change my mind about that and retune my K24 to be more in character with past Honda hi-performance 4-cylinders (IOW, I want it to freaking TAKE OFF once it hits the hi-cam). I do appreciate the low end and midrange grunt on the K24 though.
BOOMER wrote:
I really wish AH would put the TSX engine in the RXS-S if it fits, does it? The added torque should transform the RSX if it has an LSD standard.
|
|
JeffX
|
|
After owning my TSX for nearly two years I guess I have come to expect a lot from 4-cylinders.
I've driven pretty much everything that's out there in that 2.3-2.5L bracket. Nothing comes close in terms of refinement and output. Period. Then you throw in the shifter, which is truly one of the best found in any car, and it just makes it all the better.
As for the very "BEST" 4-cylinder out there, As much as I love the F20C in my S2000, I think I like the K20A from the ITR/CTR/Euro-R even better. The TSX's K24 is one of the best as well, depending upon how you score it (if you enjoy more of a "torquer" and more refinement) - it just doesn't have the specific output and "excitement" factor of the K20A (Hondata, my fingers are crossed!). The K20A packs more bottom end and midrange punch than the F20C, and sounds quite good as well. It really only yields to the F20C at the very top end, it won't quite make it to 9000rpms. I was really hoping Honda would put the ultimate K20 into the '04 S2000 refresh (9500 rpm, anyone?? 8^), but they went with the F22 instead. Now the F22 is a hell of a motor too, according to Shawn with all the engine building and tuning he's done, it's superior to a fully-built F20C. I just don't happen to much care for the gearing that Honda matched up to it in the '04-'05 S2000. They can make things right though and take the K20A to the next level with a next generration S2000 ...
EMan wrote:
Thanks to all for your very helpful and informative responses.
One last question: Is there any other 4cyl engine in a sports sedan that can compare to the TSX's? I work with a bunch of guys who believe that any German 4cyl engine but I know that cant be true. Lastly, what do you think is the "best" 4 cyl engine out there...the S2000's?
|
|
CivicB18
|
|
Are you going to write an article on the TSX after you get the Hondata? If so include baseline dyno numbers and the numbers after the Hondata program. I would like to see the results and see if it works since I will be purchasing a TSX shortly.
I really hope this gives the K24 that high RPM charge after the cams switch over. I love that with my B18c1, that rush of power.
Patrick
|
JeffX
|
|
Yes, it's one of the planned steps on our "project TSX", so there will be an article.
Actually in really cold weather the TSX motor livens up quite a bit at the top end and feels a lot more like the kind of engine I like, so i'm guessing in normal (and especially warmer) weather they are pulling a lot of timing out for some reason. Hopefully they're being overly cautious and Hondata can safely restore that.
CivicB18 wrote:
Are you going to write an article on the TSX after you get the Hondata? If so include baseline dyno numbers and the numbers after the Hondata program. I would like to see the results and see if it works since I will be purchasing a TSX shortly.
I really hope this gives the K24 that high RPM charge after the cams switch over. I love that with my B18c1, that rush of power.
Patrick
|
|
Karl O.
|
|
Jeff wrote:
I'm the other way about it. I think the TSX engine is a little out of character for the TSX, never mind a sport coupe.
I guess it would be interesting to see what it would be like, but I can't imagine it being nearly as fun as the current 2.0L motor in the '05 RSX. When I drove the Euro R in Japan, I preferred the revvy K20A to my K24. I'm hoping that Hondata will soon change my mind about that and retune my K24 to be more in character with past Honda hi-performance 4-cylinders (IOW, I want it to freaking TAKE OFF once it hits the hi-cam). I do appreciate the low end and midrange grunt on the K24 though.
BOOMER wrote:
I really wish AH would put the TSX engine in the RXS-S if it fits, does it? The added torque should transform the RSX if it has an LSD standard.
|
|
The K24 is becoming a popular swap for RSX'ers. Apparently the engine responds really well to mods. The engine definitely has the same "bottled up" feeling as the K20 in the RSX-S (well the old anyway, I haven't driven the '05) but the extra torque makes it OK. I can't wait to see what the Hondata program does.
The TSX motor is a really good design as it is, ours is up to about 4k miles and is starting to break in - seems like it keeps getting stronger. It is developing a feisty snarl under acceleration, really gives the car some attitude. I don't remember the K20 in my '02 RSX-S having the same attitude.
|
JeffX
|
|
Karl O. wrote:
Jeff wrote:
I'm the other way about it. I think the TSX engine is a little out of character for the TSX, never mind a sport coupe.
I guess it would be interesting to see what it would be like, but I can't imagine it being nearly as fun as the current 2.0L motor in the '05 RSX. When I drove the Euro R in Japan, I preferred the revvy K20A to my K24. I'm hoping that Hondata will soon change my mind about that and retune my K24 to be more in character with past Honda hi-performance 4-cylinders (IOW, I want it to freaking TAKE OFF once it hits the hi-cam). I do appreciate the low end and midrange grunt on the K24 though.
BOOMER wrote:
I really wish AH would put the TSX engine in the RXS-S if it fits, does it? The added torque should transform the RSX if it has an LSD standard.
|
|
The K24 is becoming a popular swap for RSX'ers. Apparently the engine responds really well to mods. The engine definitely has the same "bottled up" feeling as the K20 in the RSX-S (well the old anyway, I haven't driven the '05) but the extra torque makes it OK. I can't wait to see what the Hondata program does.
The TSX motor is a really good design as it is, ours is up to about 4k miles and is starting to break in - seems like it keeps getting stronger. It is developing a feisty snarl under acceleration, really gives the car some attitude. I don't remember the K20 in my '02 RSX-S having the same attitude.
|
Yes, a TSX at 4000 miles vs a TSX at 400 miles is like night and day. Mine has about 11-12k on it now and it still feels like it's loosening up a bit, though the greatest difference was the first few thousand miles.
A lot of Honda motors are like this, but the TSX's K24 seems to be affected more by this than any other Honda motor I've owned. It's to the point that if I were a dealer I'd keep a demonstrator with at least 5000 miles on it onhand so people can see for themselves how dramatic the difference is. Before I took delivery of my car I didn't even bother to drive it. I bought it solely on my experience at the press introduction. When I got my car and was driving home I thought maybe the intake inhaled a plastic bag because it felt so anemic. Then a week or two later we got the press car that I had requested several months in advance (I didn't realize i'd actually purchase one of my own so soon :) and I couldn't believe how much snappier it felt than my car.
|
cobalt
|
|
Jeff wrote:
Yes, a TSX at 4000 miles vs a TSX at 400 miles is like night and day. Mine has about 11-12k on it now and it still feels like it's loosening up a bit, though the greatest difference was the first few thousand miles.
|
I'm probably looking at a new car within another year, and this is a big issue for me. I guess I'm a little power hungry, but I'd have a hard time going back to a four cylinder after enjoying my J30 for a few years.... Even though the horsepower is the same as my '02 Accord, the difference felt very significant in my test drive, and I know it wasn't just the torque talking. Has anyone quantified the difference (dyno, 1/4 mile) of the before&after TSX break in that you know of?
On a related note, are there any rumors of a stock power bump in MY06 or MY07 without having to go aftermarket? (I'm too squeamish about such things, I know. That said, if that reflash is as good as we all hope, that could push me over the edge.)
|
MadBatsTSX
|
|
|
Any idea when Hondata will be coming out with the engine upgrades forthe TSX?
|
JeffX
|
|
MadBatsTSX wrote:
Any idea when Hondata will be coming out with the engine upgrades forthe TSX?
|
I've heard some stuff but I'm not sure I can discuss it. I'll find out what's okay to talk about and let you know :^)
|
Pauly1
|
|
|
Any infor you can share with us woul dbe great Jeff. On the TSX as well as the 05 RSX . Just a ball park range would at least be something. 1st qtr, 2nd qtr.etc.
|
JeffX
|
|
Unfortunately, I can't say anything else at the moment, but stay tuned...
Pauly1 wrote:
Any infor you can share with us woul dbe great Jeff. On the TSX as well as the 05 RSX . Just a ball park range would at least be something. 1st qtr, 2nd qtr.etc.
|
|
Pauly1
|
|
|
Allright, I will keep checking the boards. Hondata has become the area 51 of the K -series ECU.
|
99SI
|
|
|
I like this suspense. Tells me something good is probably up with the TSX :)
|
CivicB18
|
|
I dont know how much HP the TSX is making at the front wheels stock (Id say 175 ish) but with the K20's having considerable gains with Hondata and bolt ons Im sure we can expect over 210 to the wheels with ease with Hondata/bolt ons. Im glad Honda left a lot of "hidden" room for us tuners.
Patrick
|
Pauly1
|
|
|
I don't know about that. If I had to guess I think the TSX ECU will see nice torque gains as apposed to HP , but I hope i'm wrong. I am curious as to what Doug will do with the rev limiter on the TSX. With the longer stroke i'm guessing maybe a 500 rpm bump to 7,500. That also being said though I'm not sure an incresead redline will benefit TSX without changing the cams. I haven't seen enough info on the K24 yet to really guess.
|
Karl O.
|
|
|
If you'll search around some of the RSX boards you can find K24 dynos that show 200+ whp with I/H/E and the K-Pro and the RSX-S's throttle body. With specific Hondata tuning it will probably be higher. Torque is also increased substantially.
|
JeffX
|
|
In the recent analysis I've done (thanks to some well informed folks) the TSX's peak power can be stretched to some extent, but not a huge amount without going beyond the typical bolt ons. It seems to ultimately be limited by the rather timid lift and duration figures on the hi-rpm profile of the intake cam (they list the specs on intrinsic performance's website - looks puny compared to the K20A and K20A2's cams). On a stock motor the torque falls off rapidly after the VTEC transition at 6000 rpms, so higher rev limits will probably have little to no effect on power.
Another thing, the K24A2's VTC phasing mechanism is mechanically limited to only 25 degrees of phasing, and apparently Honda's not even using all of that range. In contrast, the Type-S/Type-R VTC can physically vary the phasing by double that amount. A simple cam swap should liberate some hi-rpm power and allow the TSX to develop more power and torque above 6000 rpms than it currently does. Then if you go a little further and swap in an RSX-S VTC mechanism and get the software to drive it, you have even some more potential juice on tap. But you do have to be careful about piston to valve clearance if you keep the stock slugs - the valve reliefs on the TSX pistons aren't as deep as the K20As.
I have seen some dyno plots showing some eyepopping torque and hp figures for a k-series motor with K24 geometry and fully stock honda internals (mixed and matched so things work properly) so I know the motor has some massive, ASTONISHING NA potential (way more than you might imagine...), which is all good, but as of now it seems that 200-205whp (and a healthy bump in midrange torque) may be the upper end of what you'll see on a dynojet before getting into cam swaps and stuff. I'm hoping to have the project TSX in that range fairly soon, as a matter of fact. Once I get to that point, the next step will be to get some cams and valve springs and proper computer tuning.
Also, the throttle body is actually smaller than the RSX-S's (60mm vs 62), but IIRC, it should be sufficient to deliver enough air for up to around 240whp, *IF* you have the other pieces in place to get there. So if you actually bump into that ceiling, then you can pop on an rsx-s TB and have a bit more room.
Karl O. wrote:
If you'll search around some of the RSX boards you can find K24 dynos that show 200+ whp with I/H/E and the K-Pro and the RSX-S's throttle body. With specific Hondata tuning it will probably be higher. Torque is also increased substantially.
|
|
Karl O.
|
|
That's interesting stuff- the RSX-S guys with dyno plots that I've seen are using the RSX-S throttle body because the TSX uses a drive-by-wire throttle and is therefore not compatible with the RSX K-Pro. Those guys are frankensteining the ECU/throttle body/intake manifold part of the swap just to make the 2.4L engine work in their cars.
200-205 whp is about 240 at the crank, and with the fatter torque curve most of the power should be there at lower revs. That's pretty impressive for a little NA engine and should be a blast to drive. At that point you're going to need a LSD before you go any farther in tuning the car.
|
robertoeuropean
|
|
Jeff,
you and notyper was after me few months ago when I said 5 cylinder engine and 2.5L or a little bit more should be ideal for TSX. Now, you want to go even for smaller displacement. As much as I admire your knowledge, I still repeat 5 cylinder is ideal for that car. Recently a new car has been introduced to back up my theory. A new JETTA is 2.5L inline 5. Has only 150HP (factory detuned from 175HP) and 170lbft of torque. 50Hp less with more torque than TSX, and nicer distribution of torque makes engine almost quite as can be and very peppy. As a former engineer in VW I know how much they like there engines to be responsive not necessary 0-60 fast. Recently I drove new Jetta and it is beaty. Ofcourse, it is not as fast as TSX but it is not ment to be, because than nobody will buy 2.0L turbo. Second TSX (probably the best car on the market now) with 0.26 or 0.27 CWX still boost very bad fuel consumption (same as TL who has 70Hp more and 2 cylinders more, plus all weight). That telling me that TSX engine eventhough smooth, running very hard. Only reason Acura didn't put inline 5 in my opinion is fear that such decision will jeopardise sale of TL. Acura need V8 ASAP, or TSX and TL will not have any room to go upscale. I would like to buy a TSX with TD engine and I hope they will bring it here. As well, i hope that CTDI engine will boost its output because even is quiter and smoother than competition is still behind in the power. The rason or answer is maybe in fuel efficiency.
|
JeffX
|
|
well, somebody at Honda wanted the TSX to be "responsive" too, because it's geared to be more responsive than even a 6MT TL, and I think that's where the big penalty in fuel economy comes into play. They traded that economy for responsiveness, to a large extent. I have no doubt that Honda could gear it like a civic LX and bump up the fuel economy, but then it would lose much of its driving character and it would annoy enthusiasts for whom the car is targeted.
You can short shift the TSX all day long and while your elbow and shoulder might wear out from all the gearchange activity, the motor itself doesn't have to work very hard at moving the car - it makes PLENTY of torque immediately off idle and moves the car with little effort. So, with a wider spread of gear ratios and ultimately fewer revs per mile, I'm pretty certain the car could see an improvement of around 10% (or better) in terms of fuel economy.
anyhow, my stated "wish" wasn't a product of my knowledge but simply based upon my experience. At the time I drove the 220hp Euro R in Japan, my stock TSX was back home here in the States. I preferred the high revving characteristics of the Euro R's K20A to my stock K24. The Euro R does weigh a fair bit less than the TSX, though, so I'm sure that helps offset the difference in torque between the two motors. So I would also want to see a similar weight reduction in the TSX.
Now I'm finding that some of the mods we've been evaluating as part of our "Project TSX" series of articles are really starting to transform the car into more of what I prefer, without having to give up anything in terms of driveability, responsiveness, or torque. In fact, all of these things are improving as well. I wish there was a way for us to scientifically evaluate the impact on fuel economy, but unfortunately all we can really do is test performance in terms of dyno numbers and acceleration times.
robertoeuropean wrote:
Jeff,
you and notyper was after me few months ago when I said 5 cylinder engine and 2.5L or a little bit more should be ideal for TSX. Now, you want to go even for smaller displacement. As much as I admire your knowledge, I still repeat 5 cylinder is ideal for that car. Recently a new car has been introduced to back up my theory. A new JETTA is 2.5L inline 5. Has only 150HP (factory detuned from 175HP) and 170lbft of torque. 50Hp less with more torque than TSX, and nicer distribution of torque makes engine almost quite as can be and very peppy. As a former engineer in VW I know how much they like there engines to be responsive not necessary 0-60 fast. Recently I drove new Jetta and it is beaty. Ofcourse, it is not as fast as TSX but it is not ment to be, because than nobody will buy 2.0L turbo. Second TSX (probably the best car on the market now) with 0.26 or 0.27 CWX still boost very bad fuel consumption (same as TL who has 70Hp more and 2 cylinders more, plus all weight). That telling me that TSX engine eventhough smooth, running very hard. Only reason Acura didn't put inline 5 in my opinion is fear that such decision will jeopardise sale of TL. Acura need V8 ASAP, or TSX and TL will not have any room to go upscale. I would like to buy a TSX with TD engine and I hope they will bring it here. As well, i hope that CTDI engine will boost its output because even is quiter and smoother than competition is still behind in the power. The rason or answer is maybe in fuel efficiency.
|
|
|
|
| |
![[home]](http://sohc.vtec.net/elem04/home.gif){kind=small}
![[rumors and news]](http://sohc.vtec.net/elem04/rumors.gif){kind=small}
![[model release matrix]](http://sohc.vtec.net/elem04/newmodelreleasematrix.gif){kind=small}
![[dealer network]](http://sohc.vtec.net/elem04/dealernet.gif){kind=small}
![[desktop calendar]](http://sohc.vtec.net/elem04/calendar.gif){kind=small}
![[exhaust notes]](http://sohc.vtec.net/elem04/exhaust.gif){kind=small}
![[tov forums]](http://sohc.vtec.net/elem04/forums.gif){kind=small}
![[links]](http://sohc.vtec.net/elem04/links.gif){kind=small}
![[search]](http://sohc.vtec.net/elem04/search.gif){kind=small}
![[sponsors]](http://sohc.vtec.net/elem04/sponsors.gif){kind=small}
![[garage]](http://sohc.vtec.net/elem04/garage.gif){kind=small}
![[login]](http://sohc.vtec.net/elem04/login.gif){kind=small}
