Rooftop voter

iTrader: (1)

I am going to be doing an ls/vtec turbo, and would like to be able to SAFELY rev to about 7500. I don't have the money to build the block, so that's out of the question, but am wondering if it would be ok if I did just rod bolts? If not then I won't but would like some imput. I've been doing some research and have been reading mixed things. I'm hoping to be around 300-320 after the head swap. Will that amount of horsepower have any bearing on how safely I can rev, I.E would it be safer to rev to 7500 if I was only making 220whp instead of 320 whp? Another question that's a little off topic, but if someone had a red line of lets say 8 grand, but made their highest horsepower at 5 grand, should they still take it to 8, or should they shift shortly after 5 or around there?

NJIN BUILDR

If your only turning 7500 and want to make 300 ish then don't bother with the vtec head.Lots of people make a reliable 300 hp with stock rods,ls head,and a set of forged pistons.

Rooftop voter

iTrader: (1)

to late, already got the head. I know that I can make 300 on an ls head, but the vtec head will have a better powerband. Might aswell do that, since sticking in pistons and rods costs a fortune.

NJIN BUILDR

If your limited by your rods and pistons there is no advantage to the vtec head (w/turbo).Rpm is rpm,it doesn't matter how much hp.I've got less than $400 in forged rods and pistons (used) in my daily driver.
Back to your original question.Turning 7500 won't be any problem with stock rods,with or without new bolts.

tony413

your answer is YES you can do that. my statement to you is if you already have a LS-T why not keep building that an sell your Vtec head people but them quick so that wouldnt be a problem

Sketch_hs

i used to take my stock block lsvtec turbo to 8500rpms EVERY DAMN DAY for over a year, daily driven.

so yes you can do it. besides ls blocks are cheap!

I think at 7500 rpm you are fine forever...

RC000E

I've built several LS/vtecs with arp rod bolts and acl's. All of them were revved to between 7800 and 8000 regularly without any issues. The stock rod bolts are the first line of weakness when you spin an LS, and it occurs when the piston is crossing tdc after the exhaust stroke. There's no cylinder pressure pushing down on the piston and it basically wants to let the piston shoot to the sky...the only thing stopping it are the rod bolts and it's supported by the subpar stock LS bearings.

Get the rod bolts, have the big end bore then checked to verify it's roundness wasn't distored, then use an ACL trimetal bearing.

TheCheeseWedge

iTrader: (1)

i also have a question not to thread jack
i had swapped 91 b18a1 in my crx is i was able to rev to 7800 rpms and sometimes 8000rpms and it continued to make power that high. i always thought that the redline on those motors are 6800 that is what it is on my current 91 integra? i was using stock ecu and stock motor the motor was pulled out of an oldlady integra with 120k miles. the rpms were measured on an autometer tach and tach on gauge cluster. after a about 2 1/2 years of shifting 7500rpms i spun 3 main bearings
anyone know how reving this high and still making power with this setup could be possible?

NJIN BUILDR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TheCheeseWedge &raquo;</TD></TR><TR><TD CLASS="quote">i also have a question not to thread jack
i had swapped 91 b18a1 in my crx is i was able to rev to 7800 rpms and sometimes 8000rpms and it continued to make power that high. i always thought that the redline on those motors are 6800 that is what it is on my current 91 integra? i was using stock ecu and stock motor the motor was pulled out of an oldlady integra with 120k miles. the rpms were measured on an autometer tach and tach on gauge cluster. after a about 2 1/2 years of shifting 7500rpms i spun 3 main bearings
anyone know how reving this high and still making power with this setup could be possible?</TD></TR></TABLE>

Was that seat of the pants power or measured on a dyno?

HiProfile

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TheCheeseWedge &raquo;</TD></TR><TR><TD CLASS="quote">i also have a question not to thread jack
i had swapped 91 b18a1 in my crx is i was able to rev to 7800 rpms and sometimes 8000rpms and it continued to make power that high. [snip]
anyone know how reving this high and still making power with this setup could be possible?</TD></TR></TABLE>

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

Was that seat of the pants power or measured on a dyno?</TD></TR></TABLE>

Theres a difference between pulling and continuing to make sufficient torque. Even B16/b18c engines will see their torque drop after 6k. For a *** dyno to feel torque drop off, it needs to be VERY significant, so the extent the motor no longer makes enough HP to accelerate the crankshaft.

*** dynos are like non-alcoholic beer. It may seem like it works if you try hard enough, but it really doesn't.

eg6b18boy

i used to take my stock ls with a ebay chip to 8200 daily for a good year

CivicVX94

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eg6b18boy &raquo;</TD></TR><TR><TD CLASS="quote">i used to take my stock ls with a ebay chip to 8200 daily for a good year</TD></TR></TABLE>
ebay chip FTW
I bought one and raised my redline to 10k!!! WHOA!


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rooftop voter &raquo;</TD></TR><TR><TD CLASS="quote">Will that amount of horsepower have any bearing on how safely I can rev, I.E would it be safer to rev to 7500 if I was only making 220whp instead of 320 whp? Another question that's a little off topic, but if someone had a red line of lets say 8 grand, but made their highest horsepower at 5 grand, should they still take it to 8, or should they shift shortly after 5 or around there? </TD></TR></TABLE>

The more power the engine is putting out is going to cause more wear and tare. the higher you rev an engine the more it's going to cause wear and tare. But as long as the engine is healthy you should have no problems revving to 7.5k, but I personally would upgrade the rod bolts for added assurance. Just make sure you get it dyno tuned to find out if it's even worth it to rev that high.
And to your other question, if you make your peak power at 5k, you'll want to rev a little higher, say 5.6ish so that when you shift you don't drop out of your powerband.

blwn95civic

i got a ls/vtec with the b18b block, currently NA, but ive got a skunk 2 chip in it and have been revvin to 8500 for about 8 months now, stock block, and stock rod bolts

but then again, that **** started smokin like a train after those 8 months stock rev limit on a ls is 7200 i believe, and i'm sure shifting at 7500 or a little more wouldnt phase it one bit

tegdude227

i thought the stock rev limit on ls were 6800 and fuel cut was around 7 ?

HickamHatch

my LS-T would rev to 8 no problem, but I didn't keep taking it that high cause it lost torque at 7500. That was the limit for my motor on the powerband so I kept it at 7500. Doesnt have a problem revving that high. I just upgraded to crower dual springs and tit. retainers. KEEP ON REVVIN!

Rooftop voter

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NJIN BUILDR &raquo;</TD></TR><TR><TD CLASS="quote">If your limited by your rods and pistons there is no advantage to the vtec head (w/turbo).Rpm is rpm,it doesn't matter how much hp.I've got less than $400 in forged rods and pistons (used) in my daily driver.
Back to your original question.Turning 7500 won't be any problem with stock rods,with or without new bolts.</TD></TR></TABLE>

But wouldn't there be more power all the way through the powerband because now there are cam lobes for low end and for high end, instead of just one profile?

NJIN BUILDR

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

But wouldn't there be more power all the way through the powerband because now there are cam lobes for low end and for high end, instead of just one profile?</TD></TR></TABLE>

There are way to many variables to consider.We are not talking about two set ups that are optimized.I'm saying that if I didn't have the money to get forged internals and was limiting my rpm to 7500 and hp to 320 I wouldn't spend the money I had on a ls/vtec.It just not needed for your goals.There is just so much potential in a LS-T.

TheCheeseWedge

iTrader: (1)

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

Theres a difference between pulling and continuing to make sufficient torque. Even B16/b18c engines will see their torque drop after 6k. For a *** dyno to feel torque drop off, it needs to be VERY significant, so the extent the motor no longer makes enough HP to accelerate the crankshaft.

*** dynos are like non-alcoholic beer. It may seem like it works if you try hard enough, but it really doesn't.</TD></TR></TABLE>

nah just *** dyno lol but it continued to pull until the rev limit in the crx but my integra the power falls off at around 7k and then hits a rev limit. all other ls motors ive experienced dropped off at around 7k too didnt matter what car it was in. i was just wondering what would explain that

tegman23

i had a stock ls turbo and was taking it up to 8000 and nothin ever went wrong...