[gumbalaya]

Hey guys, newbie with a question or two here!

I just bought an 04 TSX. I was curious, at what RPM does the Vtec kicks in? I owned an S2000 prevously and have driven other Civic SIs, and the Vtec engagement was noticeable, to say the least. There's no noticeable increase in acceleration rate as the RPMs increase past 4-5K, and the rate seems to actually decrease as the RPMs rise above 6K.

There are no CELs or any abnormal indications on the panel.

The previous owner used the car primarily in city driving below 60 mph, and admittedly never drove the car hard. If i asked her, she propbably wouldn't know what Vtec is.

Thanks for your help!

 

[mrgold35]

The VTEC for the TSX is 6000 rpm. You can only really feel it in 1st or 2nd gear in a 5AT. You will greatly exceeding the speed limits if you try to hit VTEC in 3rd or 4th gear for the 5AT. The 04-05 TSX engine has a little less power compared to the +06 engines. The VTEC switch over might feel a little less since the 04-05 2.4L is around 192-196 hp since Acura started using the newer HP rating measurement that change around 2006. Pretty much all Acura vehicles dropped in HP around that time and Acura upgraded some engines during the MMC to match advertised numbers and keep up with the competition (like the 06-08 TSX with 206 hp).

Hondata for $295+shipping is a cheap and easy way to lower the VTEC down to 5000 rpm, increase the Rev limit from 7300 rpm to 7600 rpm, add an extra 29 hp/ 26 tq, and smooth out the TQ curve.

Link: https://www.hondata.com/reflash-category/reflash-tsx-2004

 

[gumbalaya]

Thanks for the info!

I forgot to mention in the original post that the car is a 6MT with 123K miles. I kinda feel engagement in first & second gear, but not so much in 3rd or 4th.

When you adjust the Vtec engagement point, do they recommend higher performance valve springs/retainers, etc.? I ask b/c some S2K tuners recommend beefier valve trains when dropping the Vtec engagement down from 6K to 4300.

 

[mrgold35]

I don't think anyone has upgraded the valves/retainers with the Hondata reflash? Even when they added the Comptech S/C kit+reflash, I think they kept those parts stock (maybe just the injectors with the S/C at most). You might have to double-check with the folks that went a step above the stock Hondata reflash and did the FlashPro reflash. They seem to add more go fast parts and might have additional recommendations when installing new or possible down the road needed upgrades since everything been out for +10 years.

 

[phen8tk]

You can do the reflash out of the box without any modifications to the engine. Having bolts ons like intake, headers, and exhaust will fully maximize the reflash. However, no modifications to the engine internals are necessary. You won't need to modify the engine internals unless you plan add a turbo.

 

[Egriff]

The VTEC for the TSX is 6000 rpm. You can only really feel it in 1st or 2nd gear in a 5AT. You will greatly exceeding the speed limits if you try to hit VTEC in 3rd or 4th gear for the 5AT. The 04-05 TSX engine has a little less power compared to the +06 engines. The VTEC switch over might feel a little less since the 04-05 2.4L is around 192-196 hp since Acura started using the newer HP rating measurement that change around 2006. Pretty much all Acura vehicles dropped in HP around that time and Acura upgraded some engines during the MMC to match advertised numbers and keep up with the competition (like the 06-08 TSX with 206 hp).

Hondata for $295+shipping is a cheap and easy way to lower the VTEC down to 5000 rpm, increase the Rev limit from 7300 rpm to 7600 rpm, add an extra 29 hp/ 26 tq, and smooth out the TQ curve.

Link: Reflash - TSX 2004-2005 TSX MT/AT K24A2

Nice your only the second other person I have seen that knows the TRUE story behind the 06-08 k24a2 tsx

 

[K_A_N_O]

Thanks for the info!

I forgot to mention in the original post that the car is a 6MT with 123K miles. I kinda feel engagement in first & second gear, but not so much in 3rd or 4th.

When you adjust the Vtec engagement point, do they recommend higher performance valve springs/retainers, etc.? I ask b/c some S2K tuners recommend beefier valve trains when dropping the Vtec engagement down from 6K to 4300.

There's no need to upgrade valve springs or retainers. You only need to do that if you fit bigger cams that require it or possibly if you're going turbo or supercharged .

If you want to improve the engine and make it more like a typeR then hondata flashpro or Ktuner are the way to go for a custom tune to lower the VTEC engagement point.

My VTEC engages at 3800 ;-)