R34 25gt Performance Mods - Trying To Keep It Legal

[Eug]

here's a thought... what about a stock GTST exhaust...

they are a 2.5" exhaust standard, and should have the exact same measurements as an NA one... only thing you might need to get made up may be a replacement as to the headers instead of front pipe..

i'm currently looking into this option. its also cheap =)

[mad082]

for that stealth look but trying to get some more power, stick with the stock cat-back.

after all, its an NA car and won't respond to exhaust mods like a turbocharged car

that one of the dumbest things i have ever heard. i changed the cat back on my old magna and it made it a complete different car to drive. much more response, and much more top end.

and did full engine back exhaust and it resulted in about a 20% gain in power. on the stock exhaust it would choke at about 5500rpm, now it revs nicely up to the 7500rpm.

[WazR32GTSt]

so you have dyno results to proce this 20% power claim?

i had an MA70 supra 3L non-turbo

went from stock to aftermarket exhaust and hardly noticed a difference

on my R32 turbo, noticed a HUGE difference as shown by an increase from 106rwkw to 132rwkw from exhaust and timing change

if its "one of the dumbest things you've ever heard" then you must have your head in the sand

yes an NA car will get more power with an xhaust but its won't givve the same power gains that you will get with a turbocharged car

[SKiT_R31]

So you have dyno results to prove this 20% power claim?

I had an MA70 supra 3L non-turbo

Went from stock to aftermarket exhaust and hardly noticed a difference

On my R32 turbo, noticed a HUGE difference as shown by an increase from 106rwkw to 132rwkw from exhaust and timing change

If its "one of the dumbest things you've ever heard" then you must have your head in the sand

Yes an NA car will get more power with an exhaust but it’s won't give the same power gains that you will get with a turbocharged car

That is true, turbo's will respond to exhausts more, with increases in power and with less lag etc. But an exhaust is one of the best things you can do for a lot of N/A cars (maybe not the supra then, though I wouldn’t know). I know on my skyline, from the factory 2" exhaust with 1 muffler (other one previously cut off) to a 2.5" PRESS BENT (though its a f**king good job) with a muffler and a resonator, my car (auto) was completely different to drive, rev's quicker, gained a little low-midrange, and heaps of top end (where before it died in the arse after ~ 5000rpm) it loves it to the limiter.

Maybe a compromise, with the stock exhaust with mufflers changed??

You could always paint your exhaust black (or charcoal mixed with brown ha-ha) as long as you have a standard muffler on it (i.e. no f**king cannon) cops wont notice or care. Its quiet, it looks normal, be it a little oversize but they wont know that, and if they do, its the same difference between putting a stock turbo exhaust onto it, its still bigger...

really though, they cant stop you from replacing your exhaust, exhausts don’t last forever, they need to be done, it was already on the care and since its sound you assumed it was stock!?

I really can’t see 99.999% of cops caring about a stock looking exhaust, esp. one without a tip (not that they can do anything about that)

Its really up to the driver, rules are meant to be broken, it's just up to you to decide if its worth the risk, and at the same time, if your cars quiet and you drive sensibly (esp. in a stockish looking car) I cant see you getting pulled over or harassed at all...

though I am in Tassie and its different than some of your police states, we're still fairly strict, I have a LOUD throaty exhaust (but you only hear it when the foot goes down) way darker than legal tint, lowered, with stock wheels, polished to a mirror, I keep my car clean, and im constantly on the lookout for anything and generally drive fairly softly (but we all have our days/moments).

And even when they see my car cruise past with nothing but a throb (I always spot them first and easy off) I never get any attention. But at the same time, if I got caught being stupid, im sure I would be pretty f**ked...

Edited October 2, 2006 by SKiT_R31

[Viper_5345]

WazR32GTSt, this is for you, what sort of exausht did u put on your N/A skyline to add 30kw at the wheels???

[666DAN]

I've got a full CES custom job, looks as stock as a rock with twin tips and is good for 250rwkw....you've got to bend right up under the car to see it's a full 3" and well pushed up into every crevice to keep it out of sight. You get what you pay for with an exhaust, I'd definately go custom in the future as you just don't get the unwanted attention.

[WazR32GTSt]

WazR32GTSt, this is for you, what sort of exausht did u put on your N/A skyline to add 30kw at the wheels???

i said "exhaust + timing"

i went from having severely retarted timing and stock exhaust to having 3" dump/front and 3" cat-back (Stock cat). also fixed up the timing back to normal 20deg BTDC for the auto ECU

that took me from 106rwkw to 132rwkw

[Viper_5345]

so your car is 170kw @ wheels, what other mods u got? besides the timing and exausht.

[NA_R33]

so your car is 170kw @ wheels, what other mods u got? besides the timing and exausht.

I think your missed that his car is not NA, its a turbo.

[Viper_5345]

ahh ok, well it its quite possible to get a N/A to 170kw @ wheels.

[WazR32GTSt]

ahh ok, well it its quite possible to get a N/A to 170kw @ wheels.

an NA V8 maybe.. not an NA 6

best i've seen is a mate of mine with an NA 300zx who has 155rwkw with a hell of a lot of mods...

as said above, i've got an rb20det for my 170rwkw with FMIC, 3" exhaust, 14psi, rb25 turbo, cams+gears (as far as engine mods go anyway)

[Viper_5345]

its possible, trust me, get a r33, r32 what eva but the 2.5L throw on...exausht, extractors, CAI with pod, upgraded cams, throtle body, lightemd fly wheel, clutch and aftermarket ECU Tuned to all the mods.

that should give around 130 @ wheels minium, plsy u can always throw on 75HP of giggle gas on it, and that would throw it up, way up ^_^

[SKiT_R31]

its possible, trust me, get a r33, r32 what eva but the 2.5L throw on...exausht, extractors, CAI with pod, upgraded cams, throtle body, lightemd fly wheel, clutch and aftermarket ECU Tuned to all the mods.

that should give around 130 @ wheels minium, plsy u can always throw on 75HP of giggle gas on it, and that would throw it up, way up ^_^

it is easy possible to even get more than that... for instance, i know of a few bloody buick V67's (hardly a performance engine) that are pushin around 180RWKW...

look at engines like the L28 etc...

or for example what im looking at building up (after new job and loan clears). I dont know hows its going to turn out, but im aiming for ~ 150-160RWKW...

wont go into too much of the details of it, but im aiming for ~ 11.5:1/12:1 CR (depending on what 98ron BP ultimate can handle) RB25 VVT head on RB30 Block, maximum head porting and polish, matched intake plenum/runners, custom exaust/extractors, Stock cam, and aftermarket ECU with custom dyno tune. Usual lightweight gear (not sure how far ill go) Flywheel, lightweight single piece tailshaft, dont know about pistons - not keen on the rattle, etc.

i mean there will be a bit more to it than that, but thats the gist of things... if it doesnt make 150RWKW ill be surprised and its not really that serious of a build, heaps of daily drivability and response, nice economy when driven mild etc... Though im not soo much aiming for peak power, more for heaps of power/torque through the rev range, dont want to have to rev it too hard to make power (after reliability). - the point is, if i was to expand on that, i could easily pull a few more kw's out of it...

imo anything under 200RWKW isnt unrealistic when it comes to an N/A 6 cyl, it can be done and has been done many times, you just need the time, patiency, low blood pressure and $$$.

Once you start getting over 200RWKW you are dreaming a bit, or you are one rich muf*kr

Edited October 5, 2006 by SKiT_R31

[Eug]

skit_r31 sounds like a v.good build.. will be impressive to see how that goes.

some possible improvements may be an RB26 head with hex throttle bodies, and instead of forged pistons look into those hypereutic ones...

in terms of power i agree that realistically something around the 130-170rwkw is achieveable without nitrous, anything after that and you'll start looking at a higher rev limit and big dollars

[WazR32GTSt]

my mate with the NA zed has a heavily modified machine..

head ported + polished

extractors

twin cats and twin exhaust

pod

larger intake pipes

larger throttle bodies (there's 2 of of them also...)

unichip

and more but i don't remember what else

155rwkw (manual trans)

that's a pretty decently modified NA machine..

all that's really left to do would be cams / gears which at best could see 170-180rwkw

and that's a 3L engine, not a 2.5L like the rb25de.. 500cc makes a huge difference

[Modena]

You can get a shift kit to make it a bit less sloppy on gear-change.

Decent exhaust, porting and cams...maybe something like the new e-manage ultimate to trim the fuel and increase timing and raise the rev limit.

They are NA, they wouldnt need half the things you mentioned. Also losing a lisence should be a lesson not to speed in the first place, wait until you get off your Ps, get a turbo and then start modding.

I dont like being a father figure here but it needed to be said

PS modding an NA skyline for speed is like trying to make a fat chick a ballerina...

[Eug]

PS modding an NA skyline for speed is like trying to make a fat chick a ballerina...

bang for buck wise that may be true, but a few of the people here myself included are simply trying to build a well balanced driveable car that handles well, and has slightly more power than standard whilst maintaining reliability and keeping maintenance costs down.

you are never going to make big power or fast 1/4 mile times with an NA (in reference to a GTST), nor are you going to make big power with a GTST (in reference to lets say a GTR), nor a GTR (lets exaggerate and say a Zonda).

and while your points may be valid and true, NA cars are the base people choose have and want to work with. what i'm saying is that i'm sure most people here know about the futility of making big HP with NA cars and dont need someone telling them otherwise... and that is as a polite f**k off as you'll ever get.

also keep in mind that some of the faster cars around a track are NA, so while the fat chick cant do ballet, i'm sure she can try and do just as well.

p.s - i do not condone fat chicks.

[GTR Power]

bang for buck wise that may be true, but a few of the people here myself included are simply trying to build a well balanced driveable car that handles well, and has slightly more power than standard whilst maintaining reliability and keeping maintenance costs down.

you are never going to make big power or fast 1/4 mile times with an NA (in reference to a GTST), nor are you going to make big power with a GTST (in reference to lets say a GTR), nor a GTR (lets exaggerate and say a Zonda).

and while your points may be valid and true, NA cars are the base people choose have and want to work with. what i'm saying is that i'm sure most people here know about the futility of making big HP with NA cars and dont need someone telling them otherwise... and that is as a polite f**k off as you'll ever get.

also keep in mind that some of the faster cars around a track are NA, so while the fat chick cant do ballet, i'm sure she can try and do just as well.

p.s - i do not condone fat chicks.

GOLD

[Cubes]

its possible, trust me, get a r33, r32 what eva but the 2.5L throw on...exausht, extractors, CAI with pod, upgraded cams, throtle body, lightemd fly wheel, clutch and aftermarket ECU Tuned to all the mods.

that should give around 130 @ wheels minium, plsy u can always throw on 75HP of giggle gas on it, and that would throw it up, way up ^_^

But really why bother.. The loud exhaust note etc.. Is it really worth 130rwkw. 130rwkw is still damn slow and quite boaring.

Id simply fit up an exhaust from a turbo model, do the cam gears, pod with a nice cai and partition then tuned to suit.

[Viper_5345]

so your saying to do what i said but forget the ECU, NOS and throttel?