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What To Do Now?

Insomniac

By Insomniac,
in Engines & Forced Induction

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Insomniac

Posted
Posted

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!

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342Four Grand Master

342Four

Posted
Posted

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

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Johnny Cash Experienced

Johnny Cash

Posted
Posted

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!

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scathing Grand Master

scathing

Posted
Posted
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:

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cookie300zx Explorer

cookie300zx

Posted
Posted

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!

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Greg Veteran

Greg

Posted
Posted

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.

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Yo-Yo Grand Master

Yo-Yo

Posted
Posted

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?

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chowetime Enthusiast

chowetime

Posted
Posted

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

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