Jump to content
SAU Community

Recommended Posts

Just after some advice, as I've been getting conflicting information...

I have a N/A R33 RB25DE (S1 I'm pretty sure - Nov'93) - so far (other than aesthetics) I've done the K&N panel filter, extractors and full 2.5" exhaust, but the cat converter stayed (apparently it was fine) and I haven't put a resonator on it as yet.

I've been told the next thing I need to do is the spark plugs and getting it tuned, but others have told me that with a N/A, it's pointless/unable to be tuned cause it's a N/A with a stock computer. Is this true?

What should I do next? I know with a N/A I'm limited with what I can do, and that perfomance gains are going to be small, but what are your suggestions? Another suggestion is getting the cams done - what sort of improvement will this make, and what sort of price would I be looking at (if it's worthwhile getting this done, where in SE QLD would you recommend)?

Thanks in advance!

Link to comment
https://www.sau.com.au/forums/topic/122117-what-to-do-now/
Share on other sites

i dont no what you been told but a n/a can be tuned

go for a couple hours on a dyno with a professional dyno tuner and see what they can do - all that really will be done is timing and ignition to a degree but it will be enough to possibly extract a little more power and also make the car more reliable (less chance of detonation)

what should you do? well, with an n/a, after letting it breath properly and letting it exhale properly, the next steps usually cost big bucks.

you start getting into head work (ie cams, porting polishing, possible flow bench testing for extreme porting) and then after that is engine work (lighter conrods and pistons, changing the comp ratio higher etc, nitriding and balancing the crank etc)

something that can be done tho, that may be worthwhile, is getting a lightened flywheel and maybe balance the driveshaft. this will allow you to rev up quicker and will allow you to handle some power without destroying anything back there.

in term of cost? i wouldnt have a clue, but all those will be rather expensive

Link to comment
https://www.sau.com.au/forums/topic/122117-what-to-do-now/#findComment-2255296
Share on other sites

Ahh, the world of N/A tuning. I was into Honda's for ages, and read so much of this stuff I got sick of it...

If you're after N/A tuning, this is a very basic run-down:

1) Intake and Exhaust (inc. Extractors and High Flow Cat)

2) Plugs, Computer and dyno tuning (to maximise flowing int & exh)

3) Lightweight Flywheel and Heavy Duty Clutch

4) Time to open up the motor!

Link to comment
https://www.sau.com.au/forums/topic/122117-what-to-do-now/#findComment-2255473
Share on other sites

Leave na tuning to hondas...

Why? Nissan managed to pull over 120hp/L from their SR16VE years before Honda managed it with the K20A. Then there's the KPGC10. NA, and I don't think it'd be a good candidate for a turbo engine. If I could afford to make one into a track toy and couldn't make enough power out of the S20, I'd probably look at putting in a worked RB25DE in instead.

And there are plenty of turbo kits for Hondas out there, especially in the US. And they are making very impressive numbers.

But there's something about a hard-tuned NA engine. Its response and sound at WOT is incredible, and its something that no turbo car can match. Its just not cheap to get there. :thumbsup:

Link to comment
https://www.sau.com.au/forums/topic/122117-what-to-do-now/#findComment-2258713
Share on other sites

get a tune with an SAFC or something, bump the ignition timing a bit, get a high-flow cat before the tune, then if you need a new clutch, get a lightweight flywheel as well. after that, give up, gonna cost a shitload of money for small gains. with the stuff mentioned, you will have an enjoyable street driver, not huge power, but alot of fun i would say

Just after some advice, as I've been getting conflicting information...

I have a N/A R33 RB25DE (S1 I'm pretty sure - Nov'93) - so far (other than aesthetics) I've done the K&N panel filter, extractors and full 2.5" exhaust, but the cat converter stayed (apparently it was fine) and I haven't put a resonator on it as yet.

I've been told the next thing I need to do is the spark plugs and getting it tuned, but others have told me that with a N/A, it's pointless/unable to be tuned cause it's a N/A with a stock computer. Is this true?

What should I do next? I know with a N/A I'm limited with what I can do, and that perfomance gains are going to be small, but what are your suggestions? Another suggestion is getting the cams done - what sort of improvement will this make, and what sort of price would I be looking at (if it's worthwhile getting this done, where in SE QLD would you recommend)?

Thanks in advance!

Link to comment
https://www.sau.com.au/forums/topic/122117-what-to-do-now/#findComment-2259070
Share on other sites

Have you decided what you are going to do?

I'm considering going that extra step with my car over exhaust/intake. I was considering selling and buying a turbo for a while, and I still may. Fuel prices have got me a little worried though. Also the responsiveness of a turbo motor off boost is a concern. Would be hard to find another 'line in as good condition too. And then there is the transfer of all my aftermarket suspensions, selling my car, hassles..

Anyway I would do:

- SAFC & dyno tune (~$600)

- Lightened flywheel (~$600)

Wishlist:

- Cams (~$1000)

- Carbon fibre driveshaft (~$2000). There was a group buy thread a while ago where you could get some info.

Link to comment
https://www.sau.com.au/forums/topic/122117-what-to-do-now/#findComment-2268026
Share on other sites

Quick question,

What size extractors are the best for the rb25de?

Have they made any noticeable gains in your cars? I already have a 2.5 inch catback/piping, hotdog resonator

& looking into getting some extractors & maybe a metalcat convertor.

I was asking the guys at the exhaust shop & they said not to bother with changing the cat converter?

Link to comment
https://www.sau.com.au/forums/topic/122117-what-to-do-now/#findComment-2269024
Share on other sites

there is still a few things that can be done and it will cost but it is usually worth it... a hi flow cat is always good much less restrictions how much extra hp is unceratin but anything that creates less restriction has to be good a larger T.B and while there get the intake mani port and polished - again these will only give you maybe 10- 15hp but will make the car more throttle responsive then look at what N/A cams are available and tuning a greddy e manage is a very cheap unit to buy these days and they work very well

also look at your suspenssion does not give hp but helps make car faster on launches

Link to comment
https://www.sau.com.au/forums/topic/122117-what-to-do-now/#findComment-2269524
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Wheel alignment immediately. Not "when I get around to it". And further to what Duncan said - you cannot just put camber arms on and shorten them. You will introduce bump steer far in excess of what the car had with stock arms. You need adjustable tension arms and they need to be shortened also. The simplest approach is to shorten them the same % as the stock ones. This will not be correct or optimal, but it will be better than any other guess. The correct way to set the lengths of both arms is to use a properly built/set up bump steer gauge and trial and error the adjustments until you hit the camber you need and want and have minimum bump steer in the range of motion that the wheel is expected to travel. And what Duncan said about toe is also very true. And you cannot change the camber arm without also affecting toe. So when you have adjustable arms on the back of a Skyline, the car either needs to go to a talented wheel aligner (not your local tyre shop dropout), or you need to be able to do this stuff yourself at home. Guess which approach I have taken? I have built my own gear for camber, toe and bump steer measurement and I do all this on the flattest bit of concrete I have, with some shims under the tyres on one side to level the car.
    • Thought I would get some advice from others on this situation.    Relevant info: R33 GTS25t Link G4x ECU Walbro 255LPH w/ OEM FP Relay (No relay mod) Scenario: I accidentally messed up my old AVS S5 (rev.1) at the start of the year and the cars been immobilised. Also the siren BBU has completely failed; so I decided to upgrade it.  I got a newer AVS S5 (rev.2?) installed on Friday. The guy removed the old one and its immobilisers. Tried to start it; the car cranks but doesnt start.  The new one was installed and all the alarm functions seem to be working as they should; still wouldn't start Went to bed; got up on Friday morning and decided to have a look into the no start problem. Found the car completely dead.  Charged the battery; plugged it back in and found the brake lights were stuck on.  Unplugging the brake pedal switch the lights turn off. Plug it back in and theyre stuck on again. I tested the switch (continuity test and resistance); all looks good (0-1kohm).  On talking to AVS; found its because of the rubber stopper on the brake pedal; sure enough the middle of it is missing so have ordered a new one. One of those wear items; which was confusing what was going on However when I try unplugging the STOP Light fuses (under the dash and under the hood) the brake light still stays on. Should those fuses not cut the brake light circuit?  I then checked the ECU; FP Speed Error.  Testing the pump again; I can hear the relay clicking every time I switch it to ON. I unplugged the pump and put the multimeter across the plug. No continuity; im seeing 0.6V (ECU signal?) and when it switches the relay I think its like 20mA or 200mA). Not seeing 12.4V / 7-9A. As far as I know; the Fuel Pump was wired through one of the immobiliser relays on the old alarm.  He pulled some thick gauged harness out with the old alarm wiring; which looks to me like it was to bridge connections into the immobilisers? Before it got immobilised it was running just fine.  Im at a loss to why the FP is getting no voltage; I thought maybe the FP was faulty (even though I havent even done 50km on the new pump) but no voltage at the harness plug.  Questions: Could it be he didnt reconnect the fuel pump when testing it after the old alarm removal (before installing the new alarm)?  Is this a case of bridging to the brake lights instead of the fuel pump circuit? It's a bit beyond me as I dont do a lot with electrical; so have tried my best to diagnose what I think seems to make sense.  Seeking advice if theres for sure an issue with the alarm install to get him back here; or if I do infact, need an auto electrician to diagnose it. 
    • Then, shorten them by 1cm, drop the car back down and have a visual look (or even better, use a spirit level across the wheel to see if you have less camber than before. You still want something like 1.5 for road use. Alternatively, if you have adjustable rear ride height (I assume you do if you have extreme camber wear), raise the suspension back to standard height until you can get it all aligned properly. Finally, keep in mind that wear on the inside of the tyre can be for incorrect toe, not just camber
    • I know I have to get a wheel alignment but until then I just need to bring the rear tyres in a bit they're wearing to the belt on the inside and brand new on the outside edge. I did shorten the arms a bit but got it wrong now after a few klms the Slip and VDC lights come on. I'd just like to get it to a point where I can drive for another week or two before getting an alignment. I've had to pay a lot of other stuff recently so doing it myself is my only option 
    • You just need a wheel alignment after, so just set them to the same as current and drive to the shop. As there are 2 upper links it may also be worth adding adjustable upper front links at the same time; these reduce bump steer when you move the camber (note that setting those correctly takes a lot longer as you have to recheck the camber at each length of the toe arm, through a range of movement, so you could just ignore that unless the handling becomes unpredictable)
×
×
  • Create New...