I Want More Power? Help Please... Rb25de

[bikerboy14]

i have an r33 non turbo and i want more performance there are so many things that have been done to it but i still find it hard to get from 0-100 in less than 9seconds i crack 8seconds wen im lucky. i shift every gear at about 6 and a half grand so i dont think its running the way it should. because it has CAI,pod,high flow exhaust 3" all the way extracter as well. so i dont understand why im not getting what i what.

this is all i want 0-100kmh in 7 seconds thats it, thats all.... What do i need to do because that one second is letting me down..... will a tune do the job? an LSD? please help... i dont want to blow the engine up or have any illegal things.. and i dont want to spend to much... unless its werth it

[TwoCents]

Shed weight... spend nothing??

[carcouture]

i have an r33 non turbo and i want more performance there are so many things that have been done to it but i still find it hard to get from 0-100 in less than 9seconds i crack 8seconds wen im lucky. i shift every gear at about 6 and a half grand so i dont think its running the way it should. because it has CAI,pod,high flow exhaust 3" all the way extracter as well. so i dont understand why im not getting what i what.

this is all i want 0-100kmh in 7 seconds thats it, thats all.... What do i need to do because that one second is letting me down..... will a tune do the job? an LSD? please help... i dont want to blow the engine up or have any illegal things.. and i dont want to spend to much... unless its werth it

Maybe your exhaust is too big - you need more backpressure. When did you change oil?

[SKiT_R31]

There are zillions of these threads atm...

Legal mods? There aren’t many... When my car was N/A the first thing I did to it was fit an ultra lightweight flywheel (like 4kg), if you can find one second hand its not too pricey and it made my car a lot zippier (great improvement for off the line acceleration in a low powered car). Next would be an LSD for better launches (factory turbo would be fine, just get an auto diff so you don’t lose your short gearing), then light weight rims.

Make sure your car is in good service shape, run decent low viscosity synthetic oil, fresh spark plugs and good coil packs, using copper washers to index the plugs to face the intake will give you a small gain as well. Clean the AFM, professionally clean and flow match the injectors (to factory specs, if not possible buy new ones), high flow non oiled panel filter, check your thermo fan is loose to spin, when they get old they will tighten which over spins them and saps power (and makes your car sound like a falcon). Personally I prefer electronic thermo's (I've had a bad run, lost 1 water pump and 2 radiators to these bastards) but each to their own, just make sure its in good shape - if not then replace. Turn off your A/C!!!

Run ethanol blend fuel like E10 98ron this is just my opinion, not all share it (imo N/A RB's run better on ~ E10, leans out the richer mixes and cleans all the carbon and shit out of them, plus bonus is its cheaper) replace your fuel lines if you are concerned about them (I have never had a problem but its cheap and easy to do).

Advance your ignition timing to match the fuel, 20degree's is usually recommended but I was able to go a considerable amount further without any detonation issues with performance gains.

Weight reduction never hurts, chuck out your sub or any other crap in your car, keep less fuel in your car and just top it up more often (i.e. live on 1/4 and just put $20 in it every time you pass the servo), in some states its legal to ditch the spare wheel/jack/tools and just have that tyre fix in a can.

Thats pretty much all you can get away with doing to your car, it should make it quite snappy and run smooth as well as net you excellent economy.

Edited September 17, 2010 by SKiT_R31

[mad082]

an aftermarket ecu will help you. but ultimately there is only so much that you can do to the car without spending big bucks, and if you are the weakest link in chain then fixing you is the easiest way to drop the times. reving out to 7000rpm or 7500rpm will drop the times a bit as even though power is dropping off you will still accelerate faster in 1st gear than in second. also not sure on the gear ratios of the natros, but the turbos will do over 100kmh in 2nd, as will the natro sr20's (the missus pulsar will do about 110kmh in second).

tyres can make a difference. grippier tyres will allow you to get a better launch. also make sure you have the correct pressure in them. lower in the rear will give you better grip off the line, but after that it slows you down. too low in the front will slow you down from the moment you start moving.

if you have stiff suspension, such as coil overs, then that will be slowing you down as well because you can't get off the line as quick with stiff suspension. you will get more wheel spin.

[MBS206]

an aftermarket ecu will help you. but ultimately there is only so much that you can do to the car without spending big bucks, and if you are the weakest link in chain then fixing you is the easiest way to drop the times. reving out to 7000rpm or 7500rpm will drop the times a bit as even though power is dropping off you will still accelerate faster in 1st gear than in second. also not sure on the gear ratios of the natros, but the turbos will do over 100kmh in 2nd, as will the natro sr20's (the missus pulsar will do about 110kmh in second).

To determine shift points, you actually need to put them on a dyno, and perform a torque run in each gear.

It has often been found while it "feels" faster revvin it's nuts off, because the motor produces peak torque a 4000RMPf or example shifting early to drop back into this peak torque is often beneficial.

[Abe2]

buy a rb25det lol

in my opinion you can spend alot of money making a non turbo car go like a turbo car

but why go threw hell and back to do it when there is a easyer way

[WYTSKY]

bikerboy14 heres how to get more performance, but first these questions:

1. Are you under 21?

2. Do you live in a state where there is P plate restrictions for power/turbos?

3. Do you only have a small amount of money to spend car?

If you answered Yes to either 1 & 2 or 1/2 & 3 then unfortunately the simple answer is you can't get much more out of it until you answer no to them.

If you answered No to the questions then its pretty simple:

save up $2,000. Either get a rb25det and put it into the car or +t your current rb25de. U'll get alot more out of it then spending little bits here and there and you will be really happy with the results.

Unfortunately this is the blunt truth when modifying for decent power.

gl.

[mad082]

To determine shift points, you actually need to put them on a dyno, and perform a torque run in each gear.

It has often been found while it "feels" faster revvin it's nuts off, because the motor produces peak torque a 4000RMPf or example shifting early to drop back into this peak torque is often beneficial.

depends on the gearing though. while you can get back into better torque values, the speed that the car accelerates in the lower gear can cancel this out. in higher gears where you are spending time at the high rpm for a longer period of time this is more where you may want to shift earlier. in the case of first gear though (and second to a lesser extent), it revs up so quickly that the time it is spent past peak power outweighs being at a slightly thicker part of the torque curve. and since the OP is only talking about 0-100kmh then we don't need to bother much about the higher gears, which is why i also made the comment about whether or not it will do 100kmh in 2nd or not, because changing out of 2nd at 6500rpm will produce a slower time than reving out that last 1000rpm to get over 100kmh. this is actually the reason why in the early 90's the manual falcons were slower in 0-100kmh than the manual commodores, but were faster over the 1/4 mile. second gear in the falcon maxed out at just under 100kmh and the commodore was just over 100kmh.

then it comes down to how the car revs out as well. if the car had stock exhaust then it would start to choke at well below redline so even reving out first would be a waste of time. but the car in question is stated as having extractors and a 3" system, so it should rev out to redline reasonably well.

[SKiT_R31]

The dyno will give the torque reading at the wheels, so if you did it in each gear you could find the ideal shift point which includes both engine output and gearing.

My factory N/A does ~ 53kmph in first and ~88kmph in second, 140kmph in 3rd and 180kmph in fourth, 4.36:1 Final Drive Ratio with R32 GTR gearbox (a couple kph taller than the stock N/A box) RB25DE's run similar gbox ratio's to RB20DET gearboxes, so longer first, not sure about second.

Edited September 17, 2010 by SKiT_R31

[KezR33]

Launch downhill.

[PM-R33]

There are zillions of these threads atm...

Legal mods? There aren’t many... When my car was N/A the first thing I did to it was fit an ultra lightweight flywheel (like 4kg), if you can find one second hand its not too pricey and it made my car a lot zippier (great improvement for off the line acceleration in a low powered car). Next would be an LSD for better launches (factory turbo would be fine, just get an auto diff so you don’t lose your short gearing), then light weight rims.

Make sure your car is in good service shape, run decent low viscosity synthetic oil, fresh spark plugs and good coil packs, using copper washers to index the plugs to face the intake will give you a small gain as well. Clean the AFM, professionally clean and flow match the injectors (to factory specs, if not possible buy new ones), high flow non oiled panel filter, check your thermo fan is loose to spin, when they get old they will tighten which over spins them and saps power (and makes your car sound like a falcon). Personally I prefer electronic thermo's (I've had a bad run, lost 1 water pump and 2 radiators to these bastards) but each to their own, just make sure its in good shape - if not then replace. Turn off your A/C!!!

Run ethanol blend fuel like E10 98ron this is just my opinion, not all share it (imo N/A RB's run better on ~ E10, leans out the richer mixes and cleans all the carbon and shit out of them, plus bonus is its cheaper) replace your fuel lines if you are concerned about them (I have never had a problem but its cheap and easy to do).

Advance your ignition timing to match the fuel, 20degree's is usually recommended but I was able to go a considerable amount further without any detonation issues with performance gains.

Weight reduction never hurts, chuck out your sub or any other crap in your car, keep less fuel in your car and just top it up more often (i.e. live on 1/4 and just put $20 in it every time you pass the servo), in some states its legal to ditch the spare wheel/jack/tools and just have that tyre fix in a can.

Thats pretty much all you can get away with doing to your car, it should make it quite snappy and run smooth as well as net you excellent economy.

What the hell, that's a new one

[mad082]

yeah it's supposed to put the open side of the spark closer to incoming air/fuel mix. there is 1 major flaw in this idea and that is that by the time the air has come into the cylinder, the valve has closed and the piston has then travelled all the way back up the bore and compressed the mix, the air is going to be all over the place so it's not going to do much at all. i reakon that you'd struggle to notice the difference even on a dyno. the reason being that by using washers (even small ones) to get the plugs pointing in the direction you want, you are removing the spark plug from the chamber a bit, so you may be slowing down the amount of time it takes for all the fuel to burn, and you want it to burn as fast as possible so it is expanding while the pressure is at its peak.

[WYTSKY]

its an interesting theory, but yeh I would think spacing it out a little to make them face a certain direction would be more hindering. Personally I dont like the idea of fiddling around that area with small spacers and stuff because if anything dropped into the block ( fillings or other small bits ) ... what a pain in the ass/ motor could crap itself.

[SKiT_R31]

It’s obviously not going to gain big numbers but there is a gain, some engines benefit more than others - some like the plug facing other directions as well. The idea is also that you start the burn on the intake for it to burn across in the direction of the exhaust, intake side is also generally the most fuel saturated and colder side so any help to even the burn is good.

As long as you have the right sized copper washer it can’t go down the hole (as it has to fit around the plug thread) and once squished is going to take sfa of the plug out of the cyl, you are not going to lose power from any change in compression, that’s like saying multi-ground electrodes make more power because they take up more space (but they lose power as they cover the spark).

I'm also a big fan of having all cylinders symmetrical, if all your plugs are matched, your cyl's have equal compression and your injecting the same amount of air (and most ideal if your intake runners and exhaust primary's flow equally) you can usually get that extra couple degree's timing or slightly leaner mixtures to produce more power before you start to get detonation (whereas normally the lean hot cyl will ping earlier than the rest making you lax the tune early).

But yeah, it’s just one of those basic efficiency's, it doesn’t hurt you to do it and nets a kw or 2, if your chasing power that’s hard to get (like in an N/A) every kW counts.

[mad082]

i wasn't saying that it will alter compression, i was saying that it removes the spark plug from the chamber a little bit. yes it's SFA, but the more central to the chamber the spark plug is the better the burn will be.

if you light a fire from the centre it will burn outwards and burn faster than if you start it at 1 side