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And to add to my previous diatribe:

Two stroke engines have no torque [its argueable but generally agreed].

Turbos add torque to a motor in big gobs when they are boosting.

Think about a long stroke motor, it revs slower, but compresses a lot more volume [swept volume is usually greater], then when the bang comes it pushes against a much smaller cross sectional area because the piston/bore is smaller, the motor is 'undersquare'.

A turbo on a motor tricks the engine [tricks isn't the right word but it'll do] into acting like its compressed more volume because its added volume that is pumped in rather than drawn in.

A short stroke motor has less swept area, so it compresses a smaller amount of volume [this doesn't affect its compression ratio, it can still be as high as a long stroke and is usually higher]. And the energy from the bang is transferred to the piston crown over a wider area.

Probably boring to many, and apologies for the OT hijack.

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god of knowledge :sick:

nah it's good to have stuff lol explained very clearly

quick update car is coming along alot quicker than planned AUTOTECH are awesome they got the old motor out in no time at all which is been sold tomorrow and now i'm actually holding them up cos i'm not picking up the new motor till next saturday when i will also be picking up new radiator and fuel pump

so i think i will actually make the chrissy cruise :P

Edited by Slither

so I take it you naysayers would suggest that the 2.8l Z tune is a 'light' truck motor then?????

:laugh:

no...really...I think as many people as possible should stay with the RB26; that way if a 3l should drop to 5 cyl on the track the driver can hear the buzzing of a 9K rpm RB26 coming up behind them. not to mention that you're doing your part for aftermarket sellers in this country what with parts that either grenade or need replacing when they live at those rpms...cams, clutches, oil pumps, gears, bearings...

then there's the fitness advantage to an RB26. a part flies a long way when it lets go at 9K rpm - even if its flight is impeded by the block - so it's a long walk home, and even longer if it flies in the opposite direction and you have to go pick it up.

slither I assume you know about the pdf FIY guide for rb30 conversions? take your time and it will come together nicely, just don't get frustrated by the little detail things as they make the difference between god/dog installation. sorry if i'm teaching you to suck eggs. are you getting a new rad because your old one is buggered? what ecu are you running?

cheers

Edited by Scooby

yeah i read the rb30 guide nd was about to grab a rb30 block when i came across this http://www.skylinesaustralia.com/forums/in...&hl=rb30det for the price i really couldn't refuse, with buying anything second hand theres always a risk especially when the motor hasn't even been started yet, but the risk can some times pay off and for 1100 if there is a prob it will still work out cheaper than starting from scratch :)

Tom the guy that built this motor is a really switched on block and i feel really sorry for him spending a year buying parts and building an engine only to sell the lot to pay for a split second accident it pays to get 3rd party something i really should do!! been through a similar thing

the ecu i'm running is a link gtst i know ppl aren't to fond of these but once again got it for a steal and the features it offers a pretty sweet, map sensor, launch control, ability to control boost by the factory boost solnoid,

and pete at autotech actually seemed to really enjoying tuning it on the lap top so if he's happy than i'm happy :sick:

and yeah picking up another radiator cos the top hose connection is busted and the hose was been held on a bit dodgy didn't have any drama's but thought since it's out should do away with it and grab another one going to wollongong motorsport centre he's got 3 there 120ea so i'm thinking atleast one of them has to be in good nick

Edited by Slither

also if anyone else needs parts from sydney i'm going up next saturday with the BFV (big f*cken van) so if it's not to far out of my way i'd be happy to do a parts run for ppl

tom's injectors wouldn't be a bad buy or the turbo lol

  • 3 weeks later...

hey scooby,

yeah it seems to be coming along pretty good had a few little drama's with the motor been 4cm taller than the rb25

but it got started up on friday minus exhaust due to the dump pipe not reaching lol apparantly it sounded absolutely nuts :mellow:

motor seems to be the goods was running on all 6cyl with no knocks or anything

now it's just has to go on the dyno to have the link retuned to the new motor interested to see if beats the 25's figure of 211rwk that i ran on that dyno only 2 months ago should cos i'll be running more boost and a hi flow fuel pump now

so yeah coming along pretty good with any luck it'll be on the road for the modified nissan cruise this thursday :O

by the way for anyone interested in this criuse cos they are really good fun been on a few with the MN people there a great bunch feel free to pm for details

yeah currently it's just got the stockie on it which is going to be pretty gay really really nice down low lol but yeah probably run out of puff not far after 5 i reckon, so i'll be pretty mauch losing 2000rpm till i get a bigger turbo thinking gt35/40

speaking of which does anyone know what sort of cost you'd be looking at to get one fitted if you were to purchase a complete kit from gcg (hi mount manifold, ext wastegate, and all hoses)

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