junktionfet

My former '06 TSX had a pretty noticeable bump in power and noise when the iVTEC cam lobe switch occurred at 6000 RPM.

My current '06 VFR 800 has a very noticeable bump in power and noise when the hVTEC switch occurs at 6400 RPM.

My '07 TL-S has absolutely no discernible change in power or noise as it revs up to the rev limiter... The powerband feels fairly smooth, with a slight leveling occurring around 6500 or so. This engine of course has VTEC and a variable intake plenum... it seems like I'd hear or feel something. Even my friend's '03 TL-S has a pretty noticeable change in sound at 5000 or so.

Is it normal for the new Type S cars to feel this way or is this another problem with my car? I mean, if Honda has finally learned how to tune their VTEC and variable intake systems to be perfectly seamless, then that's awesome... However if I'm missing out on some power and sound effects, then I want to know about it!

Crysophylos

When I had some warranty work done on my 07 Type-S, I was given a TSX as a loaner. Not that I ragged on it (really I didn't), but I wanted to see what it could do. I distinctly noticed the VTEC kicking in at 6,000 RPM. When I picked up my Type-S it was then I noticed that it didn't do it, or was not nearly as noticeable. I do hear the engine rumble more at 5,300+ RPM. I'm guessing that's the VTEC kicking in, but I certainly don't notice that boost of power as in the TSX.

I'm guessing that its a smoother, more gradual transition to VTEC in the 3.5 motor given that it kicks in at a lower RPM. We'll see what others say.

Royce Han

dyno

evanj5

At WOT I dont notice the bump that much. However if I do a pull at say 60% throttle I notice the pump ALOT more.

How many miles on your car?

csmeance

From what I have head from dealers and experienced with my MDX, VTEC doesn't engage for the first 5000 miles on any new car. Before the sound in the MDX wouldn't change, but now with about 8K miles on it, it roars like a beast.

subbuzz

In my cl(3.0) I felt it when it hit vtec, and you actually felt the power,saw the rpm's rise faster and my intake barked. My guess is it's due to the lack of low end power. the tl-s compared to other cars (honda's/acura's) i've driven/raced has decent low end so when the vtec kicks in it's not felt as much.Just an educated guess,I have nothing to prove this theory...........

Bearcat94

Definetly noticable - sound and power - like the car gets a little kick in the ass.

But I tend to agree with evanj5, less noticable at WOT than 3/4 throttle. VTEC kicks in earlier in the TL-S than 6,0000 RPM; Something like 4,700 I thought.

I'd have to experiment, but if you go redline in 2nd, aren't you already in VTEC when you shift to 3rd? Same for 3rd to 4th? If so, then you'd only feel it kick in during the 2nd gear pull (that's in the TL-S, 5AT).

princelybug

iTrader: (16)

Vtec in 3G Type-S's kicks in at exactly 4,950rpm. As the OP stated, other Acura cars come with "iVtec", which is more noticeable (cam/intake) and provides more power than the "Vtec" which 3G Type-S's come with. It's a shame that our TL's don't have iVtec, but what can we do?!

Adding to what Bear stated, if you are anywhere in the rpm band above 5K, you will be in Vtec territory, and therefore will not feel the extra "kicking in" of Vtec.

junktionfet

My car has nearly 9000 miles on it now, and is a 6 speed. It doesn't matter if I'm at 1/2 or full throttle, there is no noticeable change in power or sound at 4700 or 6000 RPM... just seems like a fairly steady rise in pull until 6500 (+/-) or so when it seems to plateau. The sound from the engine of course changes gradually from a hum to a muted "roar" as the revs build, but so does any other engine.

Based on what's been said so far, it sounds like my Type-S is somewhat "normal", at WOT anyway. I suppose the high-lift cam profile is probably pretty sedate since the engine is the same used in the RL (and detuned in the MDX, etc)... That's probably why the switch is hardly noticeable.

vinnier6

iTrader: (1)

i can feel and hear it...when i took my type s in for service, they gave me a tsx...i could hear it, but couldnt feel it as the car has no power....

iforyou

iTrader: (1)

I think it has to do with the fact that, the TL-S has a large 3.5L engine (compared with 2.4L in the TSX), which has a lot more torque through out the rpm, SOHC vs DOHC (SOHC biased low end torque, DOHC is good for top end power), and possibly tuning from the factory.

I think i-VTEC actually improves low end torque, if the TL-S were to have a i-VTEC V6, then the change would be even less noticeable.

Also, I believe the TL-S 6MT (not sure about the AT) has some sort of power limiting function built into the ECU for the first 2 gears to prevent wheel spin.

T Ho

I think the TSX engages VTEC on both the intake and exhaust valves, so you get more sound on both ends. Our cars only mess with the intake side, so it will be more subtle.

I have both an '02 TL-S and an '06, and I can easily hear the VTEC on the '02, it's tough to hear on the '06. I wonder if Acura spent LOTS of time on intake tuning to keep the noise down. This is, after all, a luxury car. Perhaps the boys with the CAI can hear it better??

princelybug

iTrader: (16)

I can definitely hear it when Vtec kicks in.

princelybug

iTrader: (16)

^^^I have an AEM CAI, btw.

stillhere153

iTrader: (1)

thats why I modded mine, it didnt throw me back in my seat like a hemi, so I went out and put a couple g's on proven mods, and now, lmfao

I have an auto, so if I am highway cruzn and I stop it, it will down shift to the lower gear where the vtec range will be and lets just say there better not be a car infront of you cuz you will be all over his rear

Converted

With the AEM on the 07+ Type-S... the noise is RIDICULOUS... and awesome.

bklynpanman

vtec doesn't kick in unless your are at WOT..

tidus888

you will find the sound somewhat change at around 4500 rpm i found... look for TL dyno on youtube.. u will here it there =)

TrevTL-S

Wait a minute... are u saying that my 07 Tl-S has Vtec and not an iVtec system??? so why is it that i cannot hook up my AFC Neo??? Please clarify..i was told our cars have an iVtec setup....

I hate cars

The sound changes at 4,500rpm due to the short runner butterfiles opening in the intake. I never really felt vtec either before I switched to the 30wt oil and now it's much more noticable. On the dyno too, it didn't show a bump in torque but power climbed all the way to 7,100rpm so I assume it was working.

sunny201

What you need is a Fujita CAI. Then you will definitely notice the difference, plus you get a little more power and better gas mileage ( if you dont have a lead foot).

FiveLiterCheater

I have an AEM intake and you can deff hear the cross-over....

S PAW 1

THIS I gotta see;loL; Actually he'll be all over yours!

TeknoKing

lol!!! Yep, I can vouch for that, going 85mph in my 2G, tranny shifted to 2nd, I almost kissed the windshield, and almost got rear ended by an H2, so I consider my self lucky.

Bearcat94

^^ You guys are tough!!


Fixed it for ya.

TrevTL-S

I guess everyone ignored my question...hmm...i searched forums and gettin mixed answers...

Bearcat94

From Honda/Acura 2007 Model Year Press Releases:

http://www.hondanews.com/categories/735/releases/3747

donc

The i-VTEC works on the intake side of the cams while VTEC works both intake and exhaust. IMHO VTEC is what I want vice just the intake timing change. My 07 TL-S has the same extra push at WOT as my 05 S2000 has when VTEC is engaged. Both i-VTEC and VTEC are only engaged at WOT and engine RPM thresholds.

mrproul

what ever happened to the roar from the v-tec crossover? i know that when we put an intake on my buddy's GS-R the V-tec was so load it was awsome. how come IV-Tec kicks in at 6000 RPM's? why so late in the powerband?

junktionfet

I used to ask this question on the TSX forum when I had the '06. Dyno charts of the '04 and '05 TSX show a reasonably linear boost in power at 6000 RPM when the iVTEC cam lobes engage (on intake and exhaust). On paper it looked like fairly decent tuning from the factory.

However in '06 several significant changes were made to the K24, which resulted in higher peak power, but it also led to a much sharper rise in power at 6000 RPM. Clearly Honda didn't re-tune the ECU so the power curves for the low and high RPM cam lobes intersect, they just left it as it was. In my '06, I could sometimes feel the power beginning to slope off a bit, then at 6000 RPM it would start pulling hard again. This didn't do anything for performance, but certainly made the car "feel" quicker I suppose.

AND... The same thing happened when Honda introduced hVTEC on the VFR 800 in 2002. Originally they had it engage at 7000 RPM, which led to an abrupt powerband which apparently a lot of riders complained about. I guess it was good for wheelies

In '06 they re-tuned the ECU so hVTEC engages at 6400 RPM, which is supposedly where the two power curves intersect... it is the main reason I bought the '06 instead of an earlier model. Though I can feel when it engages on my '06, it never feels like it's going to lift the front tire... it will make you slide back in the saddle a little though

Crysophylos

Wikipedia seems to have a good write up on the various VTEC models:
http://en.wikipedia.org/wiki/VTEC

Crysophylos

In SOHC applications, I believe it affects the intake valve only.

I hate cars

Looks like our SOHC motors only use vtec on the intake side due to packaging reasons. ivtec can only be used on DOHC motors since the "i" means not only does it switch to the "big" intake and exhaust lobes but it constantly varies intake cam timing which is impossible on a SOHC motor.

stillhere153

iTrader: (1)

accuratein has a vtec controller on the blackmarket for sale, he tried to install it a while back as most guys have found out, the drive by wire screws everything up

good luck though

TrevTL-S

Thanks guys...this sucks..i got excited for a minute...i thought it can actually be done..guess my AFC Neo is still up for sale..dang!

Anyway's i do definatly feel the extra power at vtec crossover and feel the extra umph...sounds real good with a CAI

minkl81

iTrader: (2)

don't you remember tsx's ecu is purposely tuned so the torque drops significantly when ivtec is engaged? this was same for any year tsx because honda wanted any average driver could feel the ivtec and surge of power when its engaged so the car feels faster. but with non linear torque band and dropping power before the ivtec engagement, it makes tsx slower.

hondata corrected this loss in power with ecu reflash and torque band is much linear. but with the reflash, you can barely feel the vtec engaging.

so this bump in power/noise when vtec is engaged = loss in power = slower

Unit-X

I have worked for Honda since 2001 and have driven every V6 that was built from that time until now. I own a TL-S 6 Speed and a NSX and not on either car could I feel or hear the vtec engage. Only in the 4 cylinders could you actually notice the noise and power difference: s2000, integra gsr, prelude, rsx-s, and the new civic si.

cbptls

This is from Road & Track Magazine (February 2007)

What really differentiates the Type-S from the rest of the TLs is the engine. Under the hood is a 3.5-liter V-6 with VTEC that produces 286 bhp at 6200 rpm and 256 lb.-ft. of torque at 5000. Although it lacks the gusto of the other two here, it’s by far the smoothest. Drive the car in a civil manner, and it revs effortlessly, providing seamless power delivery from idle all the way to its 6800-rpm redline. Drive it hard, and VTEC makes its presence known, as the intake cams change profiles at 4950 rpm, providing an extra kick higher in the rev range. The 6-speed manual gearbox is the best transmission here (and may well be the best manual in the entire segment); the linkage has a solid overall feel, and the gates are well defined. Also, close gear ratios keep the engine consistently on the cams when driving the car spiritedly. But when it comes to acceleration, power is the name of the game, and the lack of it hurt the Type-S at the test track. It ranked last to 60 mph and through the quarter mile (5.7 and 14.3 sec., respectively).

HEK

Someone correct me if I'm wrong, but having a SOHC is the reason why when the VTEC engages makes less noise than the DOHC as I can recall when I owned a '00 Si and a '02 RSX-S....but having a CAI makes a difference in sound...can you say louder....

I hate cars

The thing I've noticed is that even though you can't feel the vtec much, the car pulls hard all the way to the revlimiter which tells me it's working. I'm sure most of you won't believe me but when I used the straight 30wt oil with no VIIs the car flat out made more power and vtec was a little more noticable. I was expecting the opposite so I doubt it's my imagination. I will never go back to the watery 5-20.