DriveSlowHomie

does anyone have a ls vtec boosted?....i have a ls motor but a gsr vtec head i can put on before boosting.....should i put on the head or just boost the ls stock?

95GSRTT

Go lsvtec if you can afford the whole swap. Will make alot more power.

Chunty Butt Kevin

doesnt vtec mess with the compression?

tegturbo

u will have higher compression so u may have to run less boost

_entropy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1.7turbo &raquo;</TD></TR><TR><TD CLASS="quote">u will have higher compression so u may have to run less boost</TD></TR></TABLE>

But because of the greatly greatly increased head flow and much more agressive cams you make more power at less boost.

GDM Z28

if your talking about a stock block leave it LS...you wont make as much power but you will make a **** load of more torque. Put it this way. a stock ls will get you 300-310whp with a good kit and tune. if you slap a vtec head on you might be able to make 330whp (20whp increase) but then your pretty much at your limits on a stock block....you might make 20whp more but your torque will go from 270-275 down to like 240. i would stay LS i had one and it was awsome!

GDM Z28

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SoFa king fast &raquo;</TD></TR><TR><TD CLASS="quote">doesnt vtec mess with the compression?</TD></TR></TABLE>

vtec has nothing to do with it...the combustion chamber on the head is what changes the compression.

Frank Castle

Talk to Tony Starks on this site. He makes over 300whp @ 8psi on a stock LS bottom end and a built head. He may be able to assist you.

Rod.

go ls/vtec

adseguy

Why mess with LS/VTAK if you are not going to upgrade internals anyway. You can push the limits of the motor with the stock block and head so why spend the extra money for ls/vtec. How much HP do you want to run and what kind of goals are you looking for.

Basically....on a stock block you won't go faster with the ls/vtec vs the stock head if you don't upgrade internals anyway

Professor15

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by adseguy &raquo;</TD></TR><TR><TD CLASS="quote">Why mess with LS/VTAK if you are not going to upgrade internals anyway. You can push the limits of the motor with the stock block and head so why spend the extra money for ls/vtec. How much HP do you want to run and what kind of goals are you looking for.

Basically....on a stock block you won't go faster with the ls/vtec vs the stock head if you don't upgrade internals anyway</TD></TR></TABLE> How wont you go faster? wouldnt the increase in airflow+better cams increase power? Generally speaking wouldnt more power create faster times? And how would you create less torque since your making more power and your stroke is the same and isnt that what greatly changes the amount of torque you create? besides bore size and other **** like that...

GDM Z28

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by drchulo &raquo;</TD></TR><TR><TD CLASS="quote"> How wont you go faster? wouldnt the increase in airflow+better cams increase power? Generally speaking wouldnt more power create faster times? And how would you create less torque since your making more power and your stroke is the same and isnt that what greatly changes the amount of torque you create? besides bore size and other **** like that...</TD></TR></TABLE>

yes it would but your missing a point...its a stock block....stock Ls will get you 300-315whp or so where a ls/vtec might get you 330....its 15whp worth loosing 30-40wtq? id rather have the torque.

Professor15

I get what your saying about it being a stock block. But how do you gain 15whp and lose 30-40wtq by just changing the head to a better flowing one? Generally speaking isnt the block what determinds how much tq you will gain not the head?

blown_LS

Hmmm i dont see why you would loose tq if you just put vtec head on. I mean the stroke stays the same so it should make more tq due to higher flowing head. Anybody else got first hand experience?

Dunc

I agree, go vtec man.....if you want I can show you two dyno charts (one without vtec on and one with vtec on). I have the ls/vtec turbo with the gsr head as well. Vtec makes a huge difference.....without vtec I think I made 238.xxwhp and with vtec I have 351.18whp

Full-Race Geoff

put the vtec head on it

DriveSlowHomie

thanx for all the responses...sounds really reasonable...yeah as for my goals...its going to be a street driven car...a 92 hatch....im just looking for right around the 300hp more or less....thats why im thinking pretty much stock block and not boosting so much...dunc you gained over 100hp with the vtec head?...thats alot of hp....how much boost?

95GSRTT

No he didnt make over 100 whp with just swapping to a vtec head, he probably turned up the boost.

dumpeDc2

just put the vtec head on because your not gonna be happy with eather for long. your gonna want to upgrade and a the lsvtec is a better base for making more power.

DriveSlowHomie

alright thanx guys...im leaning towards the lsvtec turbo....yes and putting the ls vtec wouldnt be a problem...i could basically do it myself easiy....i already have the head so just basically do the conversion...thanx for the info...any other comment is welcomed

Dunc

I didn't mess with the boost at all. I am running about 14 psi. I made that 351whp at 7500rpm. But a reason for the big gain at the top is my power curve is still rising......mainly due to the turbo cams. If you don't really believe me, I can post up my dyno charts for proof. I have no reason to lie. Oh, and mine is also a daily driver also (if that makes any difference to your decision).

I didn't just swap the head though, it had the gsr head already on it.....the boost was always at 14psi. When I was tuning, I didn't have Vtec engaging (tuning low speed cam). Then I turned on vtec and tuned the high speed cam.

GDM Z28

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dunc &raquo;</TD></TR><TR><TD CLASS="quote">I didn't mess with the boost at all. I am running about 14 psi. I made that 351whp at 7500rpm. But a reason for the big gain at the top is my power curve is still rising......mainly due to the turbo cams. If you don't really believe me, I can post up my dyno charts for proof. I have no reason to lie. Oh, and mine is also a daily driver also (if that makes any difference to your decision).

I didn't just swap the head though, it had the gsr head already on it.....the boost was always at 14psi. When I was tuning, I didn't have Vtec engaging (tuning low speed cam). Then I turned on vtec and tuned the high speed cam.</TD></TR></TABLE>

thats y.....u cant compare the nonvtec part of a vtec cam to a ls cam, the ls cam is more aggressive. i made 304whp and 270wtq at 14psi on my stock ls...hwo much torque did u make on ur lsvtec?

GDM Z28

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by drchulo &raquo;</TD></TR><TR><TD CLASS="quote">I get what your saying about it being a stock block. But how do you gain 15whp and lose 30-40wtq by just changing the head to a better flowing one? Generally speaking isnt the block what determinds how much tq you will gain not the head?</TD></TR></TABLE>

no block doesnt determine all of the torque. stroke and head flow does. if you port a head you loose torque but make alot more power and top end.


Modified by civicflnum1 at 8:52 PM 1/25/2005

GDM Z28

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cmGSR916 &raquo;</TD></TR><TR><TD CLASS="quote">thanx for all the responses...sounds really reasonable...yeah as for my goals...its going to be a street driven car...a 92 hatch....im just looking for right around the 300hp more or less....thats why im thinking pretty much stock block and not boosting so much...dunc you gained over 100hp with the vtec head?...thats alot of hp....how much boost?</TD></TR></TABLE>

if u only want 300 stay stock ls. i made 304whp/270wtq on 14psi on my sock ls

Professor15

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dunc &raquo;</TD></TR><TR><TD CLASS="quote">I didn't mess with the boost at all. I am running about 14 psi. I made that 351whp at 7500rpm. But a reason for the big gain at the top is my power curve is still rising......mainly due to the turbo cams. If you don't really believe me, I can post up my dyno charts for proof. I have no reason to lie. Oh, and mine is also a daily driver also (if that makes any difference to your decision).

I didn't just swap the head though, it had the gsr head already on it.....the boost was always at 14psi. When I was tuning, I didn't have Vtec engaging (tuning low speed cam). Then I turned on vtec and tuned the high speed cam.</TD></TR></TABLE> So your telling me that you gained 100whp just from a turbo cam? and that you were making 238whp with an ls/vtec on 14 psi? those numbers and gains seem funny to me. Post up specs of gsr and ls cams. How does headflow affect torque? Torque is the force that rotates things or turns them. this is how a car engine produces torque: The combustion of gas in the cylinder creates pressure against the piston. That pressure creates a force on the piston, which pushes it down. The force is transmitted from the piston to the connecting rod, and from the connecting rod into the crankshaft. In Figure 2, notice that the point where the connecting rod attaches to the crank shaft is some distance from the center of the shaft. The horizontal distance changes as the crankshaft spins, so the torque also changes, since torque equals force multiplied by distance. So wouldnt the increase in airflow and fuel create bigger combustions therefore making more force on the piston pushing it down and in the end making more torque?