Let's talk about VTEC

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Originally posted by saturn_boy96@Sep 9 2003, 08:31 AM
hey to get back on topic...







could some one get a vtec cam ground such that the non-vtec lobes were just as aggressive as the crower 403's and then get a really aggressive grind for the vtec cams that could potentially make power over 10,000 rpm?

yes, i've thought about this before myself. have a primary lobe cam to make power to say 7500 rpm, then vtec switch there and the vtec lobe make power from 7500-10K. i know the toda spec b's are designed kinda like that, i think their vtec xover is usually around 7K rpm, but top out around 9500
 
Originally posted by SleEPeR_CRX@Sep 9 2003, 11:36 AM
B im saying that the Vtec has alot more technology in the block and head OTHER than vtec, to make Vtec work properly that the LS doesnt have. as u have said many a time, the GSR is a better engine, so is the b16a, and so on. that being said, the LS isnt as good of an engine for Vtec for exactly those reasons. i think its smarter to keep the engine the way it was made, this obviously isnt ur opinion, but for some of us, id rather do it my own way, than doing what everyone else has done. the LS is hard to fuck up, do to lack of tuning needed to make it work. throw some cams in there and i/h/e and ur going, basic. the LS/vtec needs alot more work done to get it running smoothly. work i dont see is worth it, i have a few friends running 13's o LS/Vtec's and 1 running 12's. yes those are great #'s but what happens if u are the guy that spend $7,000 CDN on his Ls/Vtec and its running 15.3? to me the chance it will suck doesnt seem worth it.

What technologies do you claim the VTEC blocks have and the LS blocks do not? I have never seen an LSVTEC that ran poorly if it was built correctly. You go ahead and do it your way because you want to be original. That is the most piss poor reasoning I have ever heard. You want to be different, but you drive a CRX. Real different. You really ought to post some real information backing your claim because at the moment you talk a bunch adn say nothing.
 
ok heres what i have backing myself.i dont have the money to build an LS/Vtec, if i did i would rather go Ls/turbo because the LS is already best suited for turbo use, with low compression and long gearing, and not, high compression with short gearing, yes u can change the whole engine to make it work, but y not just get a GSR? thats my reasoning, yes the torque is a lil better, but for the $$ that it takes to make a real LS/Vtec run quick and be built right, u can have a GSR + mods or an LS/Vtec.
 
What about the technology you were claiming above???
but for the $$ that it takes to make a real LS/Vtec run quick and be built right, u can have a GSR + mods or an LS/Vtec

This is not true in every case. I garauntee that I got more engine for less money than I would have if I bought a GSR swap.
 
B16 Posted on Sep 9 2003, 12:53 PM
yes, i've thought about this before myself. have a primary lobe cam to make power to say 7500 rpm, then vtec switch there and the vtec lobe make power from 7500-10K. i know the toda spec b's are designed kinda like that, i think their vtec xover is usually around 7K rpm, but top out around 9500


yeah, what knd of numbers do these cams produce with an ls/vtec, or cr/vtec?

i think a cam like this would help to realize the full potential of vtec.

does anyone know the absolute highest amount of lift possible on a vtec head? .550 lift anyone?
 
Thanx for all the posts guys.

Do you guys think that a fuel pressure regulator is necessary? I didn't plan on using one for a while. And good call on the cam gears B, I almost forgot those. Thanx for the dynos too Integrals.

So, I talked to my buddy last night and we decided that swapping the pistons out to the B16s would be a lot of work for us, so he is going to hold off on those. Unless anyone in L.A. wants to come help us for a twelver or two! :beer: So the final setup looks like this -

403s
springs/retainers
port/3angle valve job
cam gears
I/H/E
ECU ?????????

As for the ECU no one has bashed my idea of the chipped ECU for now and a hondata down the road? I know chipped ECUs aren't that great but I figured that it raises the rev limiter to 8500 and remaps the fuel and ignition curves. Adjustments to the cam gears should get some real power right? Not to mention it's only 20 bux. :D How high will those cams be making power? How high should you even rev a LS motor for that matter? 10k? :lol:

Thanx for all the responses guys, keep up the good work. :thumbsup:

Edit: It appears that crower has two sets of springs. One says race and one doesn't. Which ones does he want?
 
Originally posted by saturn_boy96@Sep 9 2003, 03:43 PM
B16  Posted on Sep 9 2003, 12:53 PM
yes, i've thought about this before myself. have a primary lobe cam to make power to say 7500 rpm, then vtec switch there and the vtec lobe make power from 7500-10K. i know the toda spec b's are designed kinda like that, i think their vtec xover is usually around 7K rpm, but top out around 9500


yeah, what knd of numbers do these cams produce with an ls/vtec, or cr/vtec?

i think a cam like this would help to realize the full potential of vtec.

does anyone know the absolute highest amount of lift possible on a vtec head? .550 lift anyone?

there is more to it than simply putting in a sickly agressive cam and getting assloads of power

for those cams to do a damn thing for you you really NEED to run a high compression (13:1 or higher) the more agressive the cam the higher the compression you need

then there are issues of the valvetrain strength, fuel delivery, air flow, holding compression, etc....
 
you will need a FPR down the road, but it wont kill u to run for a while without 1, get the ones on the crower page that go with the 403's, it says spring and retainer kit under the blurb, get those, they will work best with ur setup. also, for ECU's i dont believe the LS ecu can be chipped, cuase i have friends working at VtecFrog ( a chipping company) and they say it cant be done, so your best bet is to go get a 91 Si ecu chipped. on the crower websight it shows the cams making power to 7300 RPM, but im sure they can make it to about 7600 RPM, but i wouldnt rev the LS to anywhere over 7500 RPM, or else it might get kinda iffy on the motor. but it might be a good idea to when ur putting back together the head, use ARP bolts to make sure that u have that taken care of, they are fairy cheap and way stronger than u will need, its just good to know u wont have to worry about them for a long time.
 
E_SolSi Posted on Sep 9 2003, 03:10 PM
here is more to it than simply putting in a sickly agressive cam and getting assloads of power

for those cams to do a damn thing for you you really NEED to run a high compression (13:1 or higher) the more agressive the cam the higher the compression you need

then there are issues of the valvetrain strength, fuel delivery, air flow, holding compression, etc...


i was undder the impression you only needed a lot higher compression if your cam was really aggressive and you planned on running it at a lower rpm limit. 11:1 compression at 9k is going to breathe just as much as 13:1 compression at 6k, right?
 
no....

the one thing you will hear over and over and over from people running agressive cams (toda B's and C's for instance) is that you gain top end but lose a lot of mid range

the way to hold onto midrange and make even larger gains in the top end is to run high compression pistons (toda recomends 12.5:1 + for their cams)
with higher compression you need to run higher octane fuel and tune the shit out of it

(toda was used only as a reference in this post ... the same will aply to anyones cams .... jun, skunk2, etc etc )
 
so why doesn't someone design a vtec cam that has a torque lobe for the lower rpm and a hp lobe for higher rpm.

(i was doing math for the past hour so i decided to practice my hp=tq(rpm)/5252.)

if that equation really works they could set it up for a vtec change over at 5252. say max torque on the torue lobe is 200ft/lbs@3500, that means your making a meager 133hp@3500 rpm. and then make a cam for the upper range that engages at 5300.

:thumbsup: :thumbsup: :thumbsup: for a good thread.

pg 3 :owned:
 
Originally posted by saturn_boy96@Sep 10 2003, 11:59 AM
so why doesn't someone design a vtec cam that has a torque lobe for the lower rpm and a hp lobe for higher rpm.

hello and welcome to every b-series cam there is.

if that equation really works they could set it up for a vtec change over at 5252.


the problem is, cams aren't the ONLY factor involved. a LOT of torque is compression.
 
so why can a gm pushrod make so much more torque at a low rpm?

i thought torque was all about port velocity.
 
displacement, low r/s ratios factor into torque as well

there's 24331231 ways to make torque.

there's 1 way to make horsepower- revs.
 
so why not put larger valves into a vtec head, and thendo something crazy and actually make the lift shorter on the low lift lobe, but counter that with a longer duration and a lower ramp angle?

i think this would produce a much better torque number at lower rpm.

i want to know what kind of cams eric aguilar is running in his 2.2gsr. he claims 370hp n/a.
 
where does skunk2 fit in all this? i have a friend running a gutted hatch and a crvtec and he is running mid 13's on a type r tranny and he swears by vtec technology and skunk2. has a pnp head, and a couple other itr bolt ons and a gsr head and he doesn't have the skunk2 cams yet on this motor. does crower run tham cam industry?
 
what kind of engine management is he running? does he have cam gears? exhaust? which skunk2's is he thinking about getting?
 
he is going for the stage II cams. i do think he has cam gears. no exhaust other than type r header. and apex vtec controller on his ecu. but what i want to know is first, where does skunk2 compare in price and performance per dollar compared to crower. because that is all anyone has mentioned this thread. he doesn't have that much invested in his crvtec and smokes everyone and he swears by skunk2 products. the only reason i mention him is because from the timeslips i have seen he knows his shit. plus he has worked at a car shop the last 3 years i have known him. so he must know something about cams and timing.
 
get-nick, start your own thread. don't bogart this one.
frankly, skunk2 has nothing to do with this thread at all.

Back to the lecture at hand.....
 
Originally posted by saturn_boy96@Sep 10 2003, 06:00 PM
so why not put larger valves into a vtec head, and thendo something crazy and actually make the lift shorter on the low lift lobe, but counter that with a longer duration and a lower ramp angle?

i think this would produce a much better torque number at lower rpm.

i've never seen this done, nor do i have any idea what a ramp angle is. i have no idea what kinda of numbers it would produce.

BUT- do you really want to do all that work for something that you are going to use in 1st gear, and 1st gear only? doubtful.

when you drag, you shouldn't fall out of VTEC on any upshift. if you do, you need a different tranny or differnt wheels size.

i want to know what kind of cams eric aguilar is running in his 2.2gsr. he claims 370hp n/a.


he's running toda spec D's, which are totally unstreetable. their power range is something like 7000-13,000 rpms. huge durations.
 
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