i was wonering is vtec needed for auto-x and road racing? well, not needed but benefical.

 

vtec is honda's way of having their cake and eating it too...
strikes a nice balance between fuel economy and performance

for racing purposes...no vtec is better

i-vtec is a whole different story

 

For road racing, it's definitely not needed. If you're not in VTEC, you're doing something wrong.

I don't autocross, but I would imagine that there are times that you'd choose not to downshift. In this case, you'd probably be better off if you had the non-VTEC lobe to fall back on.

 

I guess it's a a matter of how you look at it - Honda originally worked on VTEC for two purposes: Performance (the big lobe) and fuel-economy /drivability (primary & secondary lobes) so that people could have the best of both worlds (as stated in above posts)

In a true race-car, there is no need for the fuel-economy/drivability so you could ditch the primary & secondary lobes & just have the nice high lift/ long duration cams...

I think we may be getting off the subject of your question...do you have a specific question in mind - are you planning some sort of frankenstein engine?

 

[QUOTE=luder94si]
In a true race-car, there is no need for the fuel-economy/drivability so you could ditch the primary & secondary lobes & just have the nice high lift/ long duration cams...
QUOTE]

...and the vtec killer cams were created

-spenc

 

just rying to figure out if i should build my ls or swap in a vtec motor

 

well, thats more than a vtec issue. first things first. what are you going to do with the car? that will tell you how far you can go with the engine and subsequently which b-series to use/start with

-spenc

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by projectTeG &raquo;</TD></TR><TR><TD CLASS="quote">just rying to figure out if i should build my ls or swap in a vtec motor</TD></TR></TABLE>

My car has seen both. We first swapped a stock 91 LS engine and trans into my 91 Civic Hatch and i loved it. Later, the LS/VTEC head conversion was added with a B16 head with a Hondata ECU. So I got a pretty direct comparison between the two engine combos.

My verdict is this: for the street, auto cross or a rally car i would prefer the LS motor with the STOCK intake manifold. Yes. it was less powerful than the VTEC head, but the VTEC combo still had significantly less torque below 5500rpm. On a RACE TRACK with a close-ratio gearbox, a good driver can make use of that top end power. But with a stock LS gearbox its a toss up on the track and a no-brainer for the street.

The LS or CRV manifold is to often discounted as a viable design. Those super long intake runners are all about low end, which is bitchen on the street or autocrossing. Take that manifold out of the picture, and you might as well go VTEC because you are tossing out the thing that the LS is best at: TORQUE.

My car is off the street now, and is seeing use for track events only. I am still running the LS gearbox, and it is killing me. The swap to the VTEC head narrows the torque band significantly an is more or less forcing me to get a GSR or ITR gearbox to make proper use of the VTECs more limited power band. Say what you will about the VETC being designed to overcome that problem, but that is meaningless for racing. On the track, you need to be in VTEC all the time. And the right gear ratios are the only thing to make it happen.

If money is an issue and you're driving the car on the street, I'd go with the LS (or CRV) again in a heart beat. For the track, get out your wallet for the right engine and trans.


Reasonable minds may differ,

Thawley

 

most of the H1 racecars out here are running VTEC engines. with VTEC cams of some type (ITR cams, Toda A, B, C, Skunk2, etc.). i don't think i know of any of us that are running VTEC Killer cams???

i run a complete LS motor, and of course have no VTEC. i can say that the top gun B series VTEC motored cars put some serious power down....

i think it might be an advantage to have the little lobe if you do happen to hit a track where the rpms fall out of vtec range....

just an observation.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Todd Reid &raquo;</TD></TR><TR><TD CLASS="quote">i don't think i know of any of us that are running VTEC Killer cams???
</TD></TR></TABLE>

Nope, not yet. I have an engine running vtec killer cams that I hope to get tuned fairly soon. I'm looking forward to seeing how it runs.

Maybe it'll eventually make it's way into an H1 car.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JeffS &raquo;</TD></TR><TR><TD CLASS="quote">For road racing, it's definitely not needed. If you're not in VTEC, you're doing something wrong.</TD></TR></TABLE>
doing something wrong?
I am sure there are plenty of Vtec equipped H-C racers that are not in Vtec for the entire race.

 

yah...some of us are running fairly high VTEC crossover point

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thawley &raquo;</TD></TR><TR><TD CLASS="quote">


My verdict is this: for the street, auto cross or a rally car i would prefer the LS motor with the STOCK intake manifold.
The LS or CRV manifold is to often discounted as a viable design. Those super long intake runners are all about low end, which is bitchen on the street or autocrossing. Take that manifold out of the picture, and you might as well go VTEC because you are tossing out the thing that the LS is best at: TORQUE.

Thawley</TD></TR></TABLE>

So are you saying that the stock LS intake mani is the best for that engine, because it has the longer "tubes" that provide more torque?

 

[ignoramus] has anyone ever tried to make a vtec cam that tunes the 'low cam lobes' for better torque, in addition to making the 'high cam lobes' give more top-end power?[/ignoramus]

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hondan00b &raquo;</TD></TR><TR><TD CLASS="quote">has anyone ever tried to make a vtec cam that tunes the 'low cam lobes' for better torque, in addition to making the 'high cam lobes' give more top-end power?</TD></TR></TABLE>
Yes.
http://www.todaracing.com/prod....html

IIRC the B's have a small lobe close to the big lobe of the stock ITR cam.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Willard &raquo;</TD></TR><TR><TD CLASS="quote">
doing something wrong?
I am sure there are plenty of Vtec equipped H-C racers that are not in Vtec for the entire race.</TD></TR></TABLE>

I guess that wasn't written quite clearly enough...

I meant that the small lobe/big lobe cam operation isn't needed. The actual VTEC operation. With proper gearing, a good usable rpm range and competitive driver you should never need the bottom lobes of the cam. A singe profile, race cam would be fine... Thus, no need for VTEC itself, just the nice head and the tall part of the cam.

The original post mentioned autocross AND track use. Different needs, really. For H1, I'd want a built ITR motor and trans (if we're talking B-series) and for auto-x/rally/street I'd want an LS or CRV.


Reasonable minds my differ,

Thawley

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by greebler &raquo;</TD></TR><TR><TD CLASS="quote">

So are you saying that the stock LS intake mani is the best for that engine, because it has the longer "tubes" that provide more torque? </TD></TR></TABLE>

To a point. If you build the LS/CRV to rev to 9500, that manifold is crap. It'll run out of breath. But for the torque below the curve (useful for street, auto-x and rally) I'd only toss that manifold when it starts causing problems with top end and you are willing to SACRIFICE your torque for HP.

Still, you have to look at the big picture. What's the use? What's the gearing? What's the driving style? Who are you competing against? What's your budget?

Reasonable minds may differ,

Thawley