B18C: New cat back, earlier VTEC?

[shebangs]

I just got my cat back put into in my DC2 VTIR. 2.25" mandrel bent custom cat back, 1 resonator into 4" outlet canon. Only other mods I have is Injen RD1450 intake.

Anyways, I've noticed the sound difference isn't noticable anymore when I hit 5800 (previous VTEC kick in point). Now I get a very noticable lift at 4700 but when I go past ~5800, no sound difference at all. It does sound pretty crazy though.

Is it possible the exhaust has changed my VTEC point? Or is this normal and my VTEC is still coming in ~5800 as normal?

And if I can ask a completely different question. On idle, the car makes a very noticable rattling sound. Upon investigation, it's the rear bar vibrating. Only happens on idle. Whats the fix for this? Can I put something in between the rear bad and the canon? Piece of Dynomat sound deadening maybe?

Thanks,

[T-onedc2]

Simply not possible for it to have altered vtec engagement point but can affect flow of gas, ideally positively to gain some extra torque.

As for the rattle get down there and check to see if there's any contact between the exhaust system and part of the car, or perhaps the sound vibrations are causing a loose bumper mount to rattle.:thumbsup:

[dudeling7]

maybe because you got the cat back there is a little extra torque down low so its not as much of a hit aroud vtec anymore....the xhasut has smoothened the curve out thus being less noticeable?

[BeeH]

B18C, 5800 kick in point?? thought vtec on a B18C engaged at 4500??

[shebangs]

B18C, 5800 kick in point?? thought vtec on a B18C engaged at 4500??

Thats half my question. Maybe my 5800 was wrong?

Bottom end has definately improved alot, and straightened up a bit. But I havent had a chance to take it for a decent strap.

[g3vtir]

Teg VTiR Vtec kicks in at 4400 and secondary intake opens at 5800

[T-onedc2]

Just to back that up, here you go. Straight from the '96 Integra VTi-R Honda brochure ;)



http://i17.photobucket.com/albums/b55/Tykie/vtec_diagram.jpg

[kyle]

I thouhgt it was the other way round.

IAB's open at 4500 and VTEC @ 5800???

Kyle

[kyle]

cool learn something new everyday.

[BeeH]

cool learn something new everyday.
yeah same lol
dint know bout that secondary intake thingy....prolly cant hear coz my car to loud:confused:

[todaek9]

may be your catback is abit too loud, that is why you can't notice the diff when vtec kicks in...

[bennjamin]

its just NOISE.

nothing else.

[Limbo]

No it comes down to your car being more efficient with the new exhaust there is less notice of the switchover. The switchcover should now be more smoother also

[BeeH]

No it comes down to your car being more efficient with the new exhaust there is less notice of the switchover. The switchcover should now be more smoother also

yeah true, noticed that when i got a new exhaust....onli hear the switchover(sounds like a popping noise) at 4400/4500 but ne thing after that can't hear ne thing else but the car screaming....VTEC YO!!!!

[Widge]

I had the same thing Cat back exhaust a little bigger though cannon on the Back 98 VTI-R and yes i got that rattle on idle also, it has now stopped and yes couldnt hear VTEC come in at high revs either

[ATSEK4]

your vtec point will never change unless you have an after market ecu to adjust the vtec point.

if you wanna know when is vtec kick in, install a vtec light.