tony413

ok well after being annoyed to get a Vtec head for my LS i have a simple question

since the Vtec head flows more air can i just bump the Vtec engagment down to about 3500rpm?
1. because i still have my LS tranny and its not built yet
2. im not looking to rev pass 8200rpm
3. im only switching head for the fact that the Vtec flows more and i only want to use the high cam , and no buy a Vtec elimination kit

anyone thinks this is an ok idea

DaveF

you need to strap the car on the dyno to see where your optimum enguagement point would be so there are no spikes or dips in your graph. or minimum spike/dips.

tony413

i thought about that but im tring to keep my LS gearing unless i can find a GSR 3rd and 4th gear. not to many people in my area willing to do a swap they arent that mechanically inclined i on the other hand have no problem doing it.

tony413

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rota92 &raquo;</TD></TR><TR><TD CLASS="quote">The LS trans will be the death of making your car fun lol

My buddies 300 whp LS had an LS trans and it SUCKED. Now with the GSR trans it woke right up and is a blast to drive!</TD></TR></TABLE>

yeah i know thats why i need to find GSR 3rd and 4th but i'll keep my 5th for hwy driving

tony413

anyone else have any input on this

DeadVet

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rota92 &raquo;</TD></TR><TR><TD CLASS="quote">The LS trans will be the death of making your car fun lol

My buddies 300 whp LS had an LS trans and it SUCKED. Now with the GSR trans it woke right up and is a blast to drive!</TD></TR></TABLE>

A 300whp ls with ls tranny doesnt suck....Either your buddy isnt making 300whp or he cant drive for ****

93supercoupe

compared to a LS w/ a GSR trnas, yes it does very much suck.

DeadVet

Thats not what he said

HiProfile

Flowing more air isn't always a good thing for low rpm's. The reason 'typical' commuter car engines have long, narrow runners and small ports because they are optimized for low & mid-range torque. Run gigantic cams with lots of duration results in less mixing of air & fuel (atomization due to turbulance) until the engine really needs that much air.

In short, VTEC is engauged where it is because the high-cam makes less torque before 5000 rpm (arbitrairy number) than the low-cam does. If you had a supercharger pushing in loads of air, you will benifit from a low VTEC setting because its forcing tons of air into the motor. Its unlikely that you'd have a turbo producing boost at that rpm to do the same, very few people get a VTEC head and then run a straight T3...

tony413

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HiProfile &raquo;</TD></TR><TR><TD CLASS="quote">Flowing more air isn't always a good thing for low rpm's. The reason 'typical' commuter car engines have long, narrow runners and small ports because they are optimized for low & mid-range torque. Run gigantic cams with lots of duration results in less mixing of air & fuel (atomization due to turbulance) until the engine really needs that much air.

In short, VTEC is engauged where it is because the high-cam makes less torque before 5000 rpm (arbitrairy number) than the low-cam does. If you had a supercharger pushing in loads of air, you will benifit from a low VTEC setting because its forcing tons of air into the motor. Its unlikely that you'd have a turbo producing boost at that rpm to do the same, very few people get a VTEC head and then run a straight T3...</TD></TR></TABLE>

ok let me try to explain the reason i want a Vtec head. at all

1. if i were to keep my LS head get it port n polished i still wouldnt flow as much as a stock vtec head.
2. crower LS 404-405 cams are roughly the same size as a GSR-ITR high-lobe cam size. so i figure even with running the biggest cam in a PnP LS head i still wont make the same flow as a stock Vtec head with GSR or better cams. and i will have just wasted money
3. i dont want to run vtec eliminators unless i have to. i would really just like to run a vtec head using the high-lobe all the time.
4. i still have a Stock LS tranny so everytime i shift i will fall out of vtec because i only want to rev to 8200rpm. ( yes i know i should go untill i safely stop making power )

bigbadboy

stay with the LS tranny. GSR tranny is going to be too short for you. i've had both tranny's and now i have the LS and it love it to death over my GSR. this tranny is more suited for the torque this motor makes. just get your head PnP, over-sized valves, and some 404's or 405's and u'll be suprised at the difference it makes.

tony413

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bigbadboy &raquo;</TD></TR><TR><TD CLASS="quote">stay with the LS tranny. GSR tranny is going to be too short for you. i've had both tranny's and now i have the LS and it love it to death over my GSR. this tranny is more suited for the torque this motor makes. just get your head PnP, over-sized valves, and some 404's or 405's and u'll be suprised at the difference it makes. </TD></TR></TABLE>

see thats just it tho i dont wanna spend $1200 building a head only to still be disappointed that i wont break into 500Whp ATLEAST. i know that NO one wants to be a $1200 non-vtec head if i try to sell it

can anyone provide some specs of a B16 head compared to a LS head

93supercoupe

if this car is going to see anything but the track, then running in high lobe all the time is retarded.

Leave the low cam working and have it drive like stock out of boost, unless u like street driving race cars.

rorik

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony413 &raquo;</TD></TR><TR><TD CLASS="quote">

i would really just like to run a vtec head using the high-lobe all the time.
</TD></TR></TABLE>

You don't understand the point of vtec. The point is not having to make a compromise between low or high rpm power. With vtec, you have the high rpm power of big cams, like the 404s on an ls, plus the smooth idle/low/mid rpm power/fuel efficiency of smaller cams. You engage vtec too low, you'll just lose power at that rpm.

Here's how to tune the vtec engagement point. Tune your car properly with both high and low cam maps. Then do 2 dyno runs, one with the vtec set low and one with it set high. Then plot the 2 torque curves over each other, the intersection point is where you set the vtec.

bigbadboy

to make 500 it won't be that difficult i'm right at around 400 on a bone stock motor at around 15-17 PSI

SovXietday

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bigbadboy &raquo;</TD></TR><TR><TD CLASS="quote">stay with the LS tranny. GSR tranny is going to be too short for you. i've had both tranny's and now i have the LS and it love it to death over my GSR. this tranny is more suited for the torque this motor makes. just get your head PnP, over-sized valves, and some 404's or 405's and u'll be suprised at the difference it makes. </TD></TR></TABLE>

Stupid. Stupid stupid stupid.

No matter what, a shorter geared transmission is going to accelerate faster. You don't put longer gears in a transmission to get traction, that's what tires and suspension are for.

tony413

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

You don't understand the point of vtec. The point is not having to make a compromise between low or high rpm power. With vtec, you have the high rpm power of big cams, like the 404s on an ls, plus the smooth idle/low/mid rpm power/fuel efficiency of smaller cams. You engage vtec too low, you'll just lose power at that rpm.

Here's how to tune the vtec engagement point. Tune your car properly with both high and low cam maps. Then do 2 dyno runs, one with the vtec set low and one with it set high. Then plot the 2 torque curves over each other, the intersection point is where you set the vtec.</TD></TR></TABLE>

thanks for the input

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bigbadboy &raquo;</TD></TR><TR><TD CLASS="quote">to make 500 it won't be that difficult i'm right at around 400 on a bone stock motor at around 15-17 PSI</TD></TR></TABLE>

is that on a stock ls or vtec

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

Stupid. Stupid stupid stupid.

No matter what, a shorter geared transmission is going to accelerate faster. You don't put longer gears in a transmission to get traction, that's what tires and suspension are for. </TD></TR></TABLE>
sitting on some PIC selects