so basically what VTEC does is enable you to have low end torque and high end power at the same time.

what if you had a short geared tranny (like ITR or b16), high compression pistons, and some big cams that equal the lift/duration of vtec cams on a non-vtec motor? wouldn't that have about the same potential as a VTEC motor?

basically if you have LSD you can launch higher than the slow part of the powerband (down low), and the VTEC is only good because of gearing and bigger cam profiles, right? its not like boost.

 

What you have described above is basically a race car, not a street car. The reason racers use vtec head is that it flows better and the cc is smaller. Other than that, there's no difference since they don't even use vtec camshafts.

 

what do you mean racecar? i know its a racecar man, i didn't say anything about racecars/streetcars.

basically what i was asking is in the end, you can use a non vtec to achive the same goal as a vtec because with a short tranny and bigger cams, its basically what a vtec is minus the 'low end torque/high end power' advantage, right?

 

A vtec head is superior in every aspect vs. a non vtec head. People have this assumption that non-vtecs make more torque because they dont pull as hard in the top end, but its an illusion because it pulls so hard at the top vs. down low. A vtec head will pull harder in low rpms as well as high rpm. It has a smaller combustion chamber for higher compression. Better port design and large valves coupled with the advantage that vtec offers means an ls head (dollar for dollar) will never match the performance that a vtec head will offer.
One more thing. The reason race cars disable their VTEC system is for ease of tuning and the minute reliabilty factor it offers. A VTEC car will always have a flatter torque curve than one that makes similar power without VTEC.

 

The only thing that you have wrong is that the LS has better power even at low rpms. The LS motor has a boarder power band.

 

think about it logically.
A vtec head has a cam that peak power hits at 5700, but then has another that hits peak power at 7800.
The Ls has a cam that hits peak power at 6700.
With the same bottom end, the VTEC head will have a broader power band, always.

 

no way my ls has the power band from 6400-9000rpm. it only makes about 10 more hp from 6400-9000.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Allmotornonvtec &raquo;</TD></TR><TR><TD CLASS="quote">no way my ls has the power band from 6400-9000rpm. it only makes about 10 more hp from 6400-9000.</TD></TR></TABLE>
why?

 

allmotornonvtec please tell me what i need to do to fit 405's in my ls lol

 

I have 404's in my LS, what do you want to know? they are streetable, I have decent gas mileage and great midrange. I will have fabulous top end power soon, but I dont venture to the upper RPM's untill my hondata is installed. Im very, very much out of tune and can still take out modded Si's. Questions?

 

by modded Si's you must mean IHE.
Aswell, the B16 is not a good motor for drag racing at all. I'd doubt you could beat an LsVtec in an LS. If you did props...

 

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

The only thing that you have wrong is that the LS has better power even at low rpms. The LS motor has a boarder power band. </TD></TR></TABLE>

Although it has not been my finding that the LS head gives better low end torque, you must also remember that more low end torque is not the same thing as a broader power band. Having a broad powr band means that the engine is producing a high percentage of peak torque over a large RPM range. And VTEC engines are MUCH better in this respect than non-VTEC engines. Just compare a dyno of a straight LS with an LS-VTEC or B18C and you will see what I mean.

 

when i had an ls in my crx, i beat an lsvtec hatch. all the ls had done to it was intake exuahst fuelpump and header.
ive seen some people get ls heads to flowtwice as good as a b16 head

 

well i need to get 405's the biggest cam's crower makes to fit in my head. they are the ones with .502 lift, mucch bigger than your 404's lol. something needs to be done with the spring retainer seats or something, i know someone who could probably do it, i just wanted to know what had to be done.

 

remember someone saying ls got a better power band 0-6k and gsr start getting it at vtec at 6-8ish.

 

Even though I would have to vote for the vtec due to its superior design in stock form and for its value compare to a mildly built ls head. I think that with a reasonable amount of fund, any ls head can be developed to be on par with vtec. And for those people who think ls head has good torque down low, you can kiss that torque goodbye once you put on a set of race cam.

So, if we're talking about a head to head full race ls vs vtec head. There's no point of arguing which one will be faster because either one can be fast. However, in order to make a ls head as fast as a vtec one, alot more fund and development is needed. We all love vtec not because it's the fastest setup, but because it's the fastest for the dollar spent. Peace out!

 

^

ls dont make good torque because of the head design. bore/stroke

 

true, LS engines dont make torque becuase of the head. It has to do with cylinder filling properties from the low rod ratio.