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exekiel what are you using to stop detonation? you say your using pump are you also using methanol/water injection? sounds like allot of boost for 10.2:1
no methanol injection. no water injection. just fuel and air mate

my point is ... static compression has SFA to do with how much boost you can run

or how about one of the other cars ... 9.5:1 and 14psi ... and the only reason why it wasnt pushed to 20psi was because of factory valve springs being weak as piss

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Because NA engine arn't designed to run boost, hance the higher compression on NA engine. Put some positive boost into the old girl, and you'll end up splashing all your oil and a piston or two on the road.

If you were to run positive boost on an NA engine, it would be wise not to go above 5psi, though running that little boost would decimate most turbo's cause of the already high compression from the NA engine.

If your interested in running boost, if would be best to purchase a decompresion head gasket (possibly copper, but not always) to run anything over 5psi.

On that note, running 5psi on an NA engine, and driving her hard all day, you'd end up pushing out a few pistons onto the road again. so you have to be careful. Some engine are different to others though, so if you dont try you'll never know!

WTF? I was aiming for REAL results. Back up your 5psi max theory.

Cause I just posted that I have been driving around in my SR20DE+T with 9psi (which spikes to 12 or so) for at least 6 months. Its been kicking around for over 12months as it is though, I bought it like it is. Previous owner drifted it regularily.

This NA-T car has been my most reliable car yet. More so than the 3SGTE Celica and FAR more so than my R32 GTR, both of which were running close to stock boost on engines that were "MEANT" to be boosted.

Now REAL results anyone???

untitled118mx.jpg

mmmmmmm boost. Just make sure you don't drive it too hard :(

The VLT (RB30ET) doesn't run oil squirters......

I'd say 400rwhp is pushing near the limits of any RB. The Rb30's tend to have issues with much over 450rwhp, all though they have been known to hold together under street driven conditions at close to 500rwhp. They do run less rod angle than the rb25/26's so this may have some thing to do with it.

so u got it back then dan?

some people dont know what they ar talking about :)

one of the main things that limits compression ratio is the quality of the fuel

you wouldnt want to run 91RON on a 10.2:1 engine cause she would be pinging like a bitch (thats what ive seen - although hondas are pretty high comp, but i think they need premium??)

and that is especially important on a high comp turbo engine

with the turbo forcing compressed air into the piston increasing charge density and the added affect of the high comp, 91RON wold kill it, 95RON or even 98RON would be best (you can buy high comp v8 crate engines running 12:1 comp - but they have a warning not to run pump fuel unless its like 100RON or something - but only in america :P )

that is why typical turbo cars run lower comp than there n/a partners so that the added affect of the increase in charge density doesnt require a different fuel (lower comp, higher charge density allows the same fuel as a higher comp lower charge density essentially)

there is nothing wrong with decent boost on high comp as ezekial and cubes were saying - as long as your fuel is good quality and the setup is able to handle it

as ezekial said the only thing limiting the boost was the springs

wnat more boost - upgrade springs

my 2cents :D

PS thought there is nothing wrong with high comp lowish boost mmmmmmmmm :D

would sound very very nice

Amen to that = P

Turbo chariging my 96 NA GTS4 in 2months at boostworx. It be running 10:1 comp with about 5-7psi of boost, the mechanic said with good tune it be possible to run 12psi(but that requires more $$$$ > < or engine go BOOM)

. About 50% increase in power he said. If standard turbo ECU wont work he said he Remap my current Ecu.

Btw guys, My rides auto -_- (yeh yeh i know, not many gts4 came out in man). Is the Na gear box handle powerincrease? Im changing to a GTR gear box at the end of the year when i have enough mumbo $$ ^ ^ .

4wd trubo = )

NA-t all the way lol

Edited by shorty_01

Nah the pics were from when it was sitting at AAMI...they wanted $15K buyback for the wreck....so just took the full payout and bought my GTT <====

I think the stock turbo ECU will be fine for what you're doing, the timing and fuel is fairly conservative, so may match up with the high-comp turbo setup extremely well. Good luck!!!

The trick to running a high comp on pump fuel is to ensure there is minimal back pressure. Correct turbo selection.

The reason big turbo's make more power on the same boost level has everything to do with uncorking the hot side allowing the motor to expel its gas much easier, as there is less back pressure much less of the nasty hot already burnt charge sits around in the combustion chamber waiting to 'dirty' the new clean charge.

So

less back pressure = better cylinder filling = bigger bang

less back pressure = less dirty charge left behind that contaminates the new charge, the contaminated new charge is heated and as a result either less ignition advance needs to be run or a higher grade fuel used.

A GT42 running 20 odd psi on an na 10.2:1 bottom end is quite possible. Thats not looking at large cams that bleed off cylinder compression and once again improves ve (cylinder filling).

A stock turbo with a steel wheel pushing 20odd psi. Not likely. :wave:

shorty, I'll be keeping an eye on how you go down boostworx. Shall be interesting. What turbo are you running?

Hey cubes,

Running Standard S2 turbo.

Im not sure if its boostworx now because adel turbo tune (south Rd) offered me a cheaper rate.

6psi seem to be safe boost level with standard intercooler. Front mount i can boost to further.

AT the end of the day shaun from boostworx n mark from turbo tune concludes by saying its all about tuning ie. Ignition Timiing etc.

Yeh ill keep u guys posted. Conversion be completed 31 sept (thats when i have all the mumbo $$$)

BTw people just to let u know about H2P insurance (in conjunction with RAA). Theyare cheaper then Just cars etc and many others. Im currently P plator n drive na GTS4. Compre insurance = 1g. I contacted them 2day saying im modifying my engine eg turbo. Asumming my preimum will go up in the hundreds... suprisling it was $0.00 (any mods under $4,000g doesnt affect). They were nice people n knew about skyline etc... lol. Give them a Try.

Edited by shorty_01

Shorty, if I could suggest one thing. Seriously consider one of the sliding performance high-flows, at under $900 it would be awesome on the high-comp engine, plus you'd bennefit from the much larger, better flowing exhaust side. You could sell your S2 turbo to cover most of the cost.

If I had my n/a + t experience again, I'd do this no questions asked!!!

I've got this turbo on my car at the moment and think it's great with 9:1 compression :D

The trick to running a high comp on pump fuel is to ensure there is minimal back pressure. Correct turbo selection.

The reason big turbo's make more power on the same boost level has everything to do with uncorking the hot side allowing the motor to expel its gas much easier, as there is less back pressure much less of the nasty hot already burnt charge sits around in the combustion chamber waiting to 'dirty' the new clean charge.

So

less back pressure = better cylinder filling = bigger bang

less back pressure = less dirty charge left behind that contaminates the new charge, the contaminated new charge is heated and as a result either less ignition advance needs to be run or a higher grade fuel used.

A GT42 running 20 odd psi on an na 10.2:1 bottom end is quite possible. Thats not looking at large cams that bleed off cylinder compression and once again improves ve (cylinder filling).

A stock turbo with a steel wheel pushing 20odd psi. Not likely. :D

shorty, I'll be keeping an eye on how you go down boostworx. Shall be interesting. What turbo are you running?

now you're talking

my example is the VH45 engine ... and yes i have large cams but i'm only going to use them IF i need to effectively bleed off some compression

for the mean time i can use the motec to switch vvt off (push inlet closing out 20 degrees LATER) once it reaches a certain boost level which will cause detonation ... its going to take some time to get it right but will be interesting none the less :P

Because NA engine arn't designed to run boost, hance the higher compression on NA engine. Put some positive boost into the old girl, and you'll end up splashing all your oil and a piston or two on the road.

If you were to run positive boost on an NA engine, it would be wise not to go above 5psi, though running that little boost would decimate most turbo's cause of the already high compression from the NA engine.

If your interested in running boost, if would be best to purchase a decompresion head gasket (possibly copper, but not always) to run anything over 5psi.

On that note, running 5psi on an NA engine, and driving her hard all day, you'd end up pushing out a few pistons onto the road again. so you have to be careful. Some engine are different to others though, so if you dont try you'll never know!

Aswell as, if you were to turbo your car (In QLD anyway) you have to upgrade the brakes to the right size, for eq; Id turbo my Silva (Rb20DE) Id have to upgrade to the R32 5 stud brakes to comply with ADR rules, and be able to get it mod plated for the turbo.

On top of that, The gearbox would need to be replaced, and the dif. After driving it around for a while, you'd end up blowing them both.

Its cheaper to just buy a factory turbo, and not bother turbo'ing an NA car.

On top of the turbo, you have;

Dump pipe,

intercooler piping

exhaust,

brakes,

steering alignment,

wheel alignment,

wheels, :wave:

gearbox,

tailshaft (If need be)

diff,

Hicas,

ECU,

wiring loom,

plugs,

injectors,

fuel pump,

probably a fuel regulator,

compliance and,

Mod plates.

Its really not worth it in my opinion!

Mate WHAT THE f**k??

Did u just blurt out everything uve been told by mates or some shit??

For starters any engine can handle positive boost as long as it is setup correctly and in the hands of tuner that knows what he is doing.

Perhaps you would like to have a chat to my NA engine running 10.5:1 comp on 12psi thats making 300+ RWKW and tell it that it should have left a piston or two on the road... WTF... seriously mate dont spout shit if you have no idea what your talking about.

As for upgrading brakes there are ways around that with QLD main roads ADRS, something along the lines of adding a bigger engine or turbo, the car will require 4 wheel disc brakes.... that is all.. so i would talk to your engineer or do a little more study aswell.

Sorry for the rant but i hate that...

The Action Begin in 2 weeks :(

im going to have to stick with my NA 2.25 inch exhuast with cannon but installtion does inc Front n dump. Just no money for good exhuast yet :|

666DAN ,

Did your car drone when u had turbo put on due to NA exhaust or was it mellow?

I got a silencer on my car atm... taking it off it horrible :D bloody droony :O

Edited by shorty_01

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