bigmacks

i have an ls/vtec with approx. 10:1 compression, just wondering if i was to buy a turbo kit how much boost can i run safely? also do i need to upgrade injectors and retard timing?

NOTORIOUS VR

That's such a general question... it'll all depend on what turbo u'r running, how well you are able to tune the car (are u using standalone? and FMU? custom chip?), if u'r internals are forged or not, etc, etc...

Most likely you will need to upgrade u'r injectors to supply enough fuel and adjust your timing... but this has to be done on the dyno.

If you're buying a turbo kit, then I suggest you goto a reputable shop (like one of our sponsors) and they'll know exactly what will work with/for your car. If you're buliding u'r own kit then i suggest you read up and do some research.

Get-U-$um

iTrader: (1)

Do the right thing and put some 8:1 forged pistons in it and some H-beam rods. Then you can run whatever your fuel system will handle without melting the motor. Low boost high dollar turbo systems for high CR cars are ing GAY. Do it right.

v8_kllr

wouldnt doing that(8:1 pistons) basically kill the point of having ls vtec? its like having a vtec gs motor.if you run whatever your stock fuel system will handle, and think the pistons will save your ***, i think you are mistaken.

if you are running 10:1, might as well go all motor. dropping the compression is like throwing money out the window. stresses on the motor are already high enough with the ls/vtec. i say choose one or the other. all motor or turbo.

but i might be stupid.

NOTORIOUS VR

I don't think there is anything wrong with running a mild boost setup @ high compression... but you do need forged internals and a good engine management to do that.

but if you want to make serious boosted power, you'll need to drop the CR a little... 9:1 is more then enough... plus VTEC isn't dependant on CR, it'll help either way.

v8_kllr

what i was thinking of was if you are running boost on high CR, its raising your static CR to an unsafe level. i was under the impression that one of the previous posts said drop the CR(to run more boost w/o detonation) on stock fuel systems. hearing that, i was iffy on running high CR w/boost.

to each thier own i guess.

bigmacks

so i could run 5-7 psi boost and be safe or even lower then that? also what about a super charger anything different with that. i just want more power without ripping the engine apart.

v8_kllr

i personally would just bolt on the turbo without any boost controller.
obviously, get more fuel into the motor for cooling. regulator/bigger pump/etc.

air to air coolers are important.but are expensive if bought new.
notorious might have more to add, wait to see what he says as well.

SuprAdam

I did it last year by just using the wastegate to controll boost.

v8_kllr

damn you beat me to it

v8_kllr

if i ever make it out to one of the meets ill run you, and just let me win to make my heap look fast :thumbsup

NOTORIOUS VR

Like it's already been said... It all depends..

You're asking for theoretical numbers here... which really you shouldn't be worried about. PSI is not what you should be worried about. Since the CFM of the turbo is what should be more of an interest to you. And for that you'll need to know what type/size turbo you plan on using, and the VE of your engine.

Then it comes down to engine management and fuel supply. Fuel supply is easy... A set of bigger injectors, a bigger fuel pump, etc... will take care of that. But how are you going to control it? How much money are you willing to spend on this setup? You'll need an intercooler to keep the air temp's in check with that CR for sure, boost controller isn't needed if you set u'r waste gate to the desired boost level.

Ask yourself if boost is right for what you'd want... You could always go to a more radical N/A setup.

It basically comes down to cost. Proper tuning will be critical for you since u'r not going to go with forged internals, so that pretty much leaves out the "cheap" alternative of an FMU. So it's either you spend money (~$1-2g's) on a standalone unit or get someone to tune your ECU on a dyno. Then u need a manifold, turbo, intercooler, fuel system upgrades, guages, charge piping, etc, etc, etc... the list just goes on.

This isn't a small project. So let me ask you, are u planning on doing this yourself? Or are you going to have a professional shop do the work?

v8_kllr

it sounds like he hasnt even thought about the work involved with a turbo, even more work on an ls/vtec. i think he needs to think about what he wants long term with his car, before he decides if its going to be n/a or turbo.
to correct a misconception...you cannot just slap a turbo on, and it will work.
someone needs to make this kid realize what he wants before spending any money. i have a feeling he will be going all motor.