More Power

[sil25]

hi all this is my virgin post on SAU hope that someone out there can give us a hand

I've got an rb25de powered silvia and am looking to get the most out possible looking for things that people have done or know work below is a list of things already done. any and all help is appreciated.

custom made exhaust

custom made extractors

cams

cam gears

wolf 3D version 4

pod filter

custom cold intake

lightened flywheel

heavy duty clutch

Q45 throttle body

looking for really responsive engine and some more revs any ideas?

[sil25]

i've read a bit about grounding kits and voltage stablizers do these work much on NA cars if they do what sort of improvements did you get what sort of money for them? anyone had experience with them on rb25's think that they are worth having?

[NA power]

soz had to ask. what cams do you have in your engine

????

[scathing]

High compression, lightweight bottom end? You've done pretty much all the bolt-ons.

The only other thing I can think of is an intake manifold with shorter runners. That will shift your power band up in the rev range, but I have no idea what an RB25DE bottom end will rev to before breaking.

[slip]

rb30 bottome end. get it prepped, but it will sit up a bit higher (taller block on rb30).

or just build the 25 to rev hard with new valve springs and a lightweight, built bottom end.

dry sump?

personally id do the rb30, you've got everything else to make a sweet RB30DE, just needs a bottom end! 7-7500rpm, decent compression, party time in a silvia.

[Eug]

ahhh dont bullshit slip... although an RB30 block would be sweet.

RB26 head is where its at... so although he has the components to build one, they arent the best..

[screamin']

Sil25, what power is it making with those mods?

Have you had it dyno tuned, cause if you've just thrown the parts together you wont be getting the full benifit.

I've never found the 25's to be all that revy when compared to the 20's, probably just a capacity and compression thing.

What size exhaust?

You might want some bigger injectors and/or a fuel pressure regulator. A friend of mine has an RB25 with some mods, and she's had issues with the air/feul ratio, which has really killed her power output.

Cheers

[Eug]

yeah i'd like to also know power output and dyno graphs.

what is it like to drive?

[illusiVe]

carbon tail shaft?

carbon everything/strip the car do... anything u can to lightweight the car

[andylaurel]

RB26 head with open ITB's

upgrade cams to 304 duration and higher lift

stiffer valve springs

Shave the head and use dome top pistons for around 12:1 compression

some port work

should make close to 200 rwkw

[Eug]

RB26 head with open ITB's

upgrade cams to 304 duration and higher lift

stiffer valve springs

Shave the head and use dome top pistons for around 12:1 compression

some port work

should make close to 200 rwkw

tuned length extractors and to a cat-less exhaust hanging out the side and you have one hell of an NA.

not to mention a lightened flywheel and upgraded diff.

thinking about those ITB butterflies makes me wet..

[sil25]

as muh as i would love to crack the head open it is not a valid option at the moment because it is just to expensive.

the extractors that i had made are tune lenght to match the cams, i also have a hi flow cat.

I did some research into ITB's and couldn't justify the cost i went the Q45 option machined with a heavier spring. If this acts as fast as i hope it will then it should do just fine.

to put it in no uncertain terms getting the air fuel ratio right was an absolute b#$ch. it took the best part of 2 months. forgot to mention that before 600hp fuel pump and unpgraded fuel lines.

injectors are coming just looking for a good set of 440 or 444.

made 170hp at the wheels with exhaust, wolf, fuel pump, pod.

haven't done tune since the last round of work still sitting in the workshop, looking for around 270rwhp

it drives amazingly. Very responsive, smooth as silk to take off and power band is very long due to the down low torque. I strongly recommend this transplant for anyone who love the NA

hope that i answered all your questions keep the coments coming its appreciated and good to see there are others out there who respect what it takes to build a NA motor.

[2rismo]

Bottle it.

[2BNVS]

hehe i was waitin for someone (particularly adrian) to mention the bottle

ben...

[sil25]

true but it only good for a quater run. are you still considered NA if you have nos?

[Eug]

true but it only good for a quater run. are you still considered NA if you have nos?

hmm.. its debateable hey...

it is some form of forced induction, but its not something thats always used.

my stance on it is that you can run nos and be NA, its just "another mod".

same with those that consider cars that run semi-slicks to be "track cars" to me is just another mod.

[NA_R33]

In drag racing terms Nitrous is considered chemical supercharging in alot of classes... but its still naturally aspirated engine personally i would still conder it NA, stick a 75hp shot into it ull love it!! mine ran for years on it and still ran as good as the day i got it! i used to use it all the time too not just for racing, we got a bit silly with it and changed the tps activation position and started drifting with it

[scathing]

In drag racing terms Nitrous is considered chemical supercharging in alot of classes... but its still naturally aspirated engine

How is injecting a molecule stored under pressure in a bottle that breaks down into oxygen and nitrogen in any way "natural"?

[scathing]

my stance on it is that you can run nos and be NA, its just "another mod".

Where do you draw the line between "just another mod" and any other kind of mod? Everything is "just another mod".

Not trying to be argumentative - I'm just really curious about the thought processes behind how manually adding a chemical not found in the atmosphere into the intake reconciles in people's head with the definition of "natural".

[NA_R33]

Whats natural about an engine at all, or adding octane booster or different fuels. Your missing the last part... "Asperation" the engine still breathes on its on... the intake charge is under no pressure other then atmospheric... Therefore its still natural.

Going on your theory ram air intakes are the same as having a turbo...

Edited October 12, 2006 by NA_R33