I Want To Get More Revs!

[ginger]

Hey guys,

Looking at making my rb25de rev harder.

What do i need to do???

All help is good

Thanks

[Eug]

chip it and remove the rev limiter.

the harder you bury your foot the harder it revs.

simple really

[ginger]

Do i need to change valve springs at all, or do anything like that??

[inthisglass]

Eug, when you say chip it, what chip in particular?

cheers

karl

[bryyy]

You may want to look at getting more power rather than more revs.

Whats the point in revving if your not making power?

[funkymonkey]

high revs are for small displacement honda's... see if you can make more torque out of the RB25 down low in the RPM.

But if you want to rev higher you'll need to remove the rev limiter on the ECU using either a cut defender or a modded ECU. You'll also have to make sure your engine and cooling can support higher revs.

[scathing]

  funkymonkey said:

high revs are for small displacement honda's...

Don't those hardcore GT-R motors spin to 11,000RPM?

[funkymonkey]

  scathing said:

Don't those hardcore GT-R motors spin to 11,000RPM?

only momentarily till their passenger side floorwell comes apart at the welds, flies free and chops someone's head off.

[scathing]

  funkymonkey said:

only momentarily till their passenger side floorwell comes apart at the welds, flies free and chops someone's head off.

Surely you'd be yelling "shut up" first, and slamming your laptop lid down.

[funkymonkey]

  scathing said:

Surely you'd be yelling "shut up" first, and slamming your laptop lid down.

The thought did cross my mind when it started flashing "danger to manifold".

[skyla]

  bryyy said:

You may want to look at getting more power rather than more revs.

Whats the point in revving if your not making power?

Have to agree with this, no point having a car thats revving it's nuts off, all that you end up doing is making more noise and no extra power.

Here's a dyno chart of my car to prove that more revs don't equall more power. The dyno was done in 3rd gear and let go untill red line. Btw my car is running an after market ECU (GTS Link), I've kept red line at the factory limit as my car stops making power at around 6200rpm.

If you are wanting more top end power and get the engine reving harder you will need to open it up and replace the standard cams with something a little bigger, the down side of this it gets very expensive very quickly and you will also need to replace the stock ECU.

Edited October 15, 2007 by skyla

[ztuned]

a lil off topic, but does anyone know when the speed cut kicks in, in a r33 gtst series 2? the car has a piggy back SAFC, would that make a difference? cheers

i know this is the NA section, but shouldnt make a difference right...

[funkymonkey]

afaik its just a fuel and ignition cut at over 180km/h

[ztuned]

if u were referring to my post...i dun quite understand lol

[Eug]

  ginger said:

Do i need to change valve springs at all, or do anything like that??

nah, valve bounce is ideal.

on a more serious note you'd want to do some block and head work to see revs reliably

  inthisglass said:

Eug, when you say chip it, what chip in particular?

cheers

karl

i prefer smith's thins.

you'd be looking at an aftermarket ecu or something like dr. drift (sam's) chips

  funkymonkey said:

The thought did cross my mind when it started flashing "danger to manifold".

lol

  ztuned said:

a lil off topic, but does anyone know when the speed cut kicks in, in a r33 gtst series 2? the car has a piggy back SAFC, would that make a difference? cheers

i know this is the NA section, but shouldnt make a difference right...

  funkymonkey said:

afaik its just a fuel and ignition cut at over 180km/h

  ztuned said:

if u were referring to my post...i dun quite understand lol

he was referring to yours.

basically speed cut at 180km/hr is a fuel & ignition cut. by having an SAFC it 'should' have removed it, check your manual. i know my SAFC2 has removed it.

[GTS4WD]

Im with all of the above..

Learn to abuse the engine with the power it has now.

I do alot of togue style driving. I find that alot of the poke is ~4.5K and above (25DE VCT). Keep it above that when exiting the corner and you'll find the car is accutally quite quick! Even Id call it decently quick! ME! Who always bitches about how slow and heavy my car is!

I think the ideal thing you want that will suite all the criteria, a lightened flywheel. It will make the engine rev out quicker, you wont gain any power, perhaps a minisqule amount of torque. But the engine will be a whole much more user friendly!

Over that, the usual:

Port and polish

Cams (you will need to retune/chip, NA Z32 is a cheap alurnative)

and once cams are dont.. headers and zoers.. or the other way around is better..

BUT then you need block work.. rods, rod bolts.. and while your there.. shave.. and that all time and $$$ lots of $$$ and if you dont know how to do it.. some deadshit putting his paws all over the car.. and you dont know...

then with more power..

suspention - too much $$

brakes - *SPEW!*

oh fcuk it!.. the modification bussiness licks balls..

just be happy with what you have .. or buy an Elise

Edited October 16, 2007 by GTS4WD

[GTS4WD]

besides.. you shouldnt be reving it 7000K anyways.. its brutal.. you look like a kook and your acctually making LESS power AND torque than if you change gears up..

[scathing]

  bryyy said:

Whats the point in revving if your not making power?

As long as you're not losing a great deal of power, a higher cutout gives you a bit more rev range to play with. Even if the power curve falls away a little, it can still have advantages.

I'll put it this way. My generation of VQ35DE has a stock redline of 6600RPM. I've bumped it up to 7200RPM. When me and a mate in similar cars were at Wakefield, we'd come out of Turn 2 and head up the hill. The distance to the next corner means that he hits the cutout probably a second before his braking point. That means he either has to bang it off the cutout, lift off the throttle, or grab another gear (and go back down a gear for the corner). All of which loses time. I just keep my foot pinned, and so I keep accelerating (albeit slowly) up to our braking point.

Even though I'm not making a great deal of power in that extra 600RPM, not having to stop accelerating gives me a major advantage in terms of my point to point speed.

Its the same if you're in a corner where your revs are up near redline. If you grab the next gear you lose a lot of punch, but with the stock cutout you might find yourself too close to the limiter.

Just remember that you can always short shift a car, regardless of what it revs to, and all else being equal the car's behaviour doesn't change. Allowing the engine to overrev past the cutout, on the other hand, is a lot more difficult.

[GTS4WD]

Its just too brutal for me..

I see the advantages in this.. but i just dont think i have the heart to do it..

Stupid question but what exactly is the correct process of short shfting?.. I heard so many different interpretations of this I need to clear this up..

[gtr660hp]

its not real smart revving an RB say more than 500 revs past the factory recommended...unless you are planning to do some internal upgrades...anyway a stock n/a RB wont make any more power by revving it to 8000...it will become breathless and past its efficiency point...all it will do is hurt the engine in the long run