Change VTEC Engagement
05-14-2012, 01:00 PM
#1
Instructor
Thread Starter
Change VTEC Engagement
Did a quick search but couldn't find anything...
But is there anything out there for TL's (Or TL Type S's) that lower engagement point when VTEC kicks in?
Like something along the lines of Hondata for the RSX...I had my ECU reflashed that adjusted air/fule ratios and also lowered the point at which VTEC engages...I think it lowered it to 5200 as opposed to 6000.
If there is a thread already like this, mods you may close this thread as you see fit. Thanks!
But is there anything out there for TL's (Or TL Type S's) that lower engagement point when VTEC kicks in?
Like something along the lines of Hondata for the RSX...I had my ECU reflashed that adjusted air/fule ratios and also lowered the point at which VTEC engages...I think it lowered it to 5200 as opposed to 6000.
If there is a thread already like this, mods you may close this thread as you see fit. Thanks!
05-14-2012, 01:12 PM
#2
We have a ECU available to us.
its called the J&R ECU.
Rodney has played with the vtec engagement points, and found that lowering the vtec engagement from 4700RPM to 4k, the torque curve isnt flat.
While changing it to 5k RPM you get a solid straight torque band.
Acura changed the vtec engagement point for the TL-s', to, you guessed it, 5k RPM.
in other words, our six cylinder is not like any 4 cylinder in terms of gaining power by lowering vtec.
its called the J&R ECU.
Rodney has played with the vtec engagement points, and found that lowering the vtec engagement from 4700RPM to 4k, the torque curve isnt flat.
While changing it to 5k RPM you get a solid straight torque band.
Acura changed the vtec engagement point for the TL-s', to, you guessed it, 5k RPM.
in other words, our six cylinder is not like any 4 cylinder in terms of gaining power by lowering vtec.
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05-14-2012, 01:19 PM
#3
Instructor
Thread Starter
We have a ECU available to us.
its called the J&R ECU.
Rodney has played with the vtec engagement points, and found that lowering the vtec engagement from 4700RPM to 4k, the torque curve isnt flat.
While changing it to 5k RPM you get a solid straight torque band.
Acura changed the vtec engagement point for the TL-s', to, you guessed it, 5k RPM.
in other words, our six cylinder is not like any 4 cylinder in terms of gaining power by lowering vtec.
its called the J&R ECU.
Rodney has played with the vtec engagement points, and found that lowering the vtec engagement from 4700RPM to 4k, the torque curve isnt flat.
While changing it to 5k RPM you get a solid straight torque band.
Acura changed the vtec engagement point for the TL-s', to, you guessed it, 5k RPM.
in other words, our six cylinder is not like any 4 cylinder in terms of gaining power by lowering vtec.
05-14-2012, 01:58 PM
#4
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05-14-2012, 02:07 PM
#5
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^ha! justin got pwned.
05-14-2012, 02:17 PM
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05-14-2012, 03:00 PM
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^yeah but my redline moved up 
05-14-2012, 05:04 PM
#10
I'm confused. Where does it seem like the stock 3G TL 3.2L engage VTEC too soon? Looks pretty seamless to me, and typically (incredibly) flat in true Honda fashion.
Last edited by 94eg!; 05-14-2012 at 05:09 PM.
05-14-2012, 08:35 PM
#11
Three Wheelin'
Our vtec engagement is very very smooth....so smooth that it's poinless. I don't understand why they couldn't make DOHC.
If you can safely increase redline by 500rpm rather than lower vtec. MUCH better results.
If you can safely increase redline by 500rpm rather than lower vtec. MUCH better results.
05-15-2012, 01:26 AM
#12
The motor would cost a shit-ton more. Think of the price difference between a D16Z and a B16A. Then adjust for 20 years of inflation, then multiply by two (two heads). Plus they were already having trouble putting power down on crappy Truanza tires anyways. lol NM. Lets get a DOHC VTEC V8 already. Yes with 8k+ redline.
Last edited by 94eg!; 05-15-2012 at 01:28 AM.
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05-15-2012, 12:52 PM
#14
Racer
The motor would cost a shit-ton more. Think of the price difference between a D16Z and a B16A. Then adjust for 20 years of inflation, then multiply by two (two heads). Plus they were already having trouble putting power down on crappy Truanza tires anyways. lol NM. Lets get a DOHC VTEC V8 already. Yes with 8k+ redline.
Other companies are able to get away with DOHC V6s because they typically have much less complex valve-train arrangements.
05-15-2012, 01:59 PM
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05-15-2012, 02:13 PM
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^^^ 
05-15-2012, 04:14 PM
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here is the vtec engagement video from Rodney....this is from the JnR ECU:
05-15-2012, 05:06 PM
#22
Three Wheelin'
05-15-2012, 07:02 PM
#23
Typically the OEM set's a torque jump after vtec. Especially on the performance DOHC models. This allows potential buyers to "feel" that they are getting something extra during the test drive. Even though they are still loosing out a little in the mid range. Though my personal experience with my stock 05 6MT would have to concur with the dynos I posted earlier. I can't feel any difference in torque before or after. Just smooth pull straight to redline.
PS: DOHC VTEC is tit's when you have a really loud exhaust. Makes SOHC's seem like garbage. For a luxury sports sedan though, the SOHC VTEC definitely gets the job done. Who knows, maybe someday we will get a DOHC VTEC V8 for the streets. Maybe something like this with it's 8-4-2-1 Header that runs the entire length of the car. lol
Last edited by 94eg!; 05-15-2012 at 07:04 PM.
05-16-2012, 08:49 AM
#26
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That's cool...but they must be comparing changes on a JNR basemap. It may have to do with their ignition or fuel curves being better for the low-cam (or worse for the high-cam). Since they have no way of re-using the stock Honda/Keihin basemap, it's not really a fair comparison for the OEM ECU. I've never once seen a Honda ECU run with a dip AFTER vtec.
Typically the OEM set's a torque jump after vtec. Especially on the performance DOHC models. This allows potential buyers to "feel" that they are getting something extra during the test drive. Even though they are still loosing out a little in the mid range. Though my personal experience with my stock 05 6MT would have to concur with the dynos I posted earlier. I can't feel any difference in torque before or after. Just smooth pull straight to redline
Typically the OEM set's a torque jump after vtec. Especially on the performance DOHC models. This allows potential buyers to "feel" that they are getting something extra during the test drive. Even though they are still loosing out a little in the mid range. Though my personal experience with my stock 05 6MT would have to concur with the dynos I posted earlier. I can't feel any difference in torque before or after. Just smooth pull straight to redline
right as the video was showing the curve after the tune of the ECU....here are the pix on the stock ECU....
Car: 6MT (04 i think) mods AEM intake + Greddy exhaust + STOCK ECU + 3rd gear run:
Same Car and same mods + 4th gear run:
Same Car and mods include AEM Intake + Greddy Exhaust + STOCK ECU + PCD's + JPIPE + 4th gear run:
So if you see all these runs are on the stock ECU with the VTEC engaging at 4700 rpm....and there is a dip from 4000-4200 rpm....the lost HP comes back at around 4500 rpm.....
again if the VTEC didnt create a dip like that then why would it be moved to 4950 rpm in the Type S models ?
05-16-2012, 09:12 AM
#27
So if you see all these runs are on the stock ECU with the VTEC engaging at 4700 rpm....and there is a dip from 4000-4200 rpm....the lost HP comes back at around 4500 rpm.....
again if the VTEC didnt create a dip like that then why would it be moved to 4950 rpm in the Type S models ?
again if the VTEC didnt create a dip like that then why would it be moved to 4950 rpm in the Type S models ?
It is very interesting the graphs you posted. I would suspect the mods to the car, even the simple bolt on's, cause the engine to desire a higher vtec changeover. Too bad we don't have a stock baseline of this specific car to compare. If I were to put money on it, I would suspect the CAI has caused a complete shift in the powerband. This means both the low and high cams now make peak torque at a higher rpm. This would require a higher vtec crossover as we are seeing. Of course that is just a guess.
***edit: I also just noticed something. If you look the bottom of the 1st 2 graphs, you will notice a lean condition occurring at the vtec crossover. Can't explain why that is happening, but that might also account for the sudden torque drop. Of course the 3rd graph is running way rich and it's still got that dip as well.
Last edited by 94eg!; 05-16-2012 at 09:18 AM.
05-16-2012, 09:22 AM
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^^^ 94eg!
in retrospect, i think the 3rd graph is for 6MT with AEM CAI and Greddy Intake with the JnR ECU tuned and hence its running rich....in this graph the VTEC engagement is not changed/controlled by the the JnR but the stock ECU....
in retrospect, i think the 3rd graph is for 6MT with AEM CAI and Greddy Intake with the JnR ECU tuned and hence its running rich....in this graph the VTEC engagement is not changed/controlled by the the JnR but the stock ECU....
05-16-2012, 10:43 AM
#30
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^yeah it plugs right up to the stock ECU. very easy...each harness just plugs into the correct port and they're all labeled for easy identification.
05-16-2012, 01:42 PM
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11-14-2012, 07:45 PM
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I think its 4700 and some change....
Justn, didnt they change the the VTEC on the base after 06?
Justn, didnt they change the the VTEC on the base after 06?
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11-15-2012, 07:14 AM
#37
since i got my exhaust...i've been thinking about a few things on making my car faster...ahaha...
im tempted to pull the trigger on the RV6 V3...and pcd...
these mods may be down the road...so im curious....i just wanna hit 300 whp thats it maybe a bit more
Edit: Without Super Charging
im tempted to pull the trigger on the RV6 V3...and pcd...
these mods may be down the road...so im curious....i just wanna hit 300 whp thats it maybe a bit more
Edit: Without Super Charging
11-15-2012, 09:58 AM
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^^^ so what has any of those mods gotta do with VTEC engagement?
11-15-2012, 08:35 PM
#40
Instructor
One thing to note with the Type-S is that it has vtec on the intake and exhaust valves where as the base has only on exhaust. Not sure if that would really be a reason for them to change it but who knows...