How To Get More Power From A Naturally Aspirated (na) Engine

[dori34]

but then a tune no matter if its na or turbo will works wonders for the car...

[Eug]

you can advance timing without ecu...

my opinion, unless you plan (or have) alot of mods to back it up the ecu wont give you the gains you are probably expecting. it is still going to be an additional 10~20 maybe 30kw.

compression, port, polish, cam shafts, cam gears, intake work, extractors, will net you a sweet figure.

remember the basic formula for power = air + fuel. remember in an NA system you cant just up the boost boost/air, the only way to do that is to make everything flow better, then you can add more fuel!!

[inthisglass]

i would like very much to know how to advance the timing with out the ecu!

i was always under the impression the timing was all handled by the ecu.

so an emanage or a safc2 will sort out my running very rich problems?

[Eug]

not ignition timing though! rotate the crank angle sensor.

[inthisglass]

so i could physically rotate the crank angle sensor on the front of the engine but it would put my ignition firing out of sync?

is it worth doing the timing and ignition or would i be best to just do the air/fuel ratios?

i was thinking that for 98 octane fuel i would need a slight timing advance as the 100 octane fuel over in japan land is alot more resistant to compression etc and the timing doesnt need to be as advanced.

atleast thats my understanding of it, please correct me if im wrong.

[342Four]

i think you would want to retard teh timing a bit

your aim is to advance the timing as much as possible - but it is based on 100RON fuel whereas your running 98RON - so you want to retard it according to that

however - i think you can get away with a few degrees of timing advance on the crank angle sensor without knocking

[inthisglass]

so basically i need someone to rotate the crank angle sensor a few degrees and then get my air/fuel ratio fixed up to sort everything out?

its running really rich and it stinks, literally.

[342Four]

have you tried an ecu reset karl??

not sure on the nissan method of resetting the ecu, but on my excel you disconnect the positive terminal when the car is still warm - leave it for about 15 min, then drain the capacitors in teh ecu by holding my foot on the brake for about 20 seconds

then reconnect the positive terminal straight away and drive the car for about 30 min so the ecu 'gets used to' your driving style

[unarmed_skyline]

yup pretty much the same method, unplug the battery then drain the charge by holding down brake pedal for a while, then start her up and drive round in ur normal driving style be it calm or thrash whatever u do most, and let it learn agian.

[inthisglass]

I reset the ecu yesterday

went for a quick drive to get the car up to operating temperature

got home and took off the positive battery terminal

sat on the break for about a minute

through battery back in and went for a drive for about half an hour

i noticed the car does run slightly smoother now

seems a bit happier after the reset

thanks for the suggestion everyone.

[Gerg_R31]

with that "how to port at home"

majority of info was there but this is whats missing

inbalance flow of all ports and/or ridiculously oversized ports can screw the power and response. always have someone with a flow bench, if not CC match the ports not as effective but can give a closer result

with the rb series motors they use more suction so with the ports the best power gains is from stopping any restrictions, enlarging reduces the sucking effect which in the end reduces power

there is no where 2 actually learn 2 port, porting is mostly trial and error and learning that while something may work with 1 type of head it may not for another

and if you do porting at home as a first time never say "its good enough" its either good or not

also im researching converting the rb25 VCT to non VCT so far I've put a bung into the face of the head, currently looking into replacing the hydrualic buckets with the solid buckets with shims or lash pads,

all i know is the lash pad kit (sits on the valve) from tomeii is like $2k and the extra length of the valve that is needed is under the bucket

where as the solid shim (sits on retainer) pretty cheap gts-r rb26 second hand but would have to replace the retainers and get longer valves

rb25 intake valves compared to rb26 intake valves, the rb26 valve head is wider, over all length is longer, valve stem same diameter

exhaust valves in the rb26 has a bigger head, longer and wider stem, looking at seeing if the rb26 exhaust guides are compatable with the rb25s exhaust guides

[lammy426]

heres my rb25de figures,as anybody got more out of a rb25de,thanks john

heres my latest dyno results,any coments please

Edited July 13, 2008 by lammy426

[-R33GTS-]

Lammy

This thread is about gaining performance out of a Naturally aspirated RB25. without a Turbocharger

You've put a turbo onto your car - you're using Forced Induction.. I'm sure I said that to you in another thread..

By everybody refering to their motor as an "RB25de" for example, they're meaning their car is only a "DE" not a "DET" with a turbo - Like yours.

I know you've added the Turbo after the car's production to technically it's an RB25DE+T - still a turbo.

You clearly haven't stated in the post that your car is a Turbo, Which looks to me like you're wanting everybody to "WOW!!!" "COOL MAN!" "Can we be friends??" etc.

I feel like an asshole saying this.. but stop pulling your willy please

xoxox

[lammy426]

Lammy

This thread is about gaining performance out of a Naturally aspirated RB25. without a Turbocharger

You've put a turbo onto your car - you're using Forced Induction.. I'm sure I said that to you in another thread..

By everybody refering to their motor as an "RB25de" for example, they're meaning their car is only a "DE" not a "DET" with a turbo - Like yours.

I know you've added the Turbo after the car's production to technically it's an RB25DE+T - still a turbo.

You clearly haven't stated in the post that your car is a Turbo, Which looks to me like you're wanting everybody to "WOW!!!" "COOL MAN!" "Can we be friends??" etc.

I feel like an asshole saying this.. but stop pulling your willy please

xoxox

yes i know but months ago i put figures up when i had 350bhp and some people might be interested in what they can get out of their engines and some did show an interest even if you don't

[NZ Slider]

A couple of pages back, cant be bothered finding it, it was stated that all the skyline suspension setups etc were very similar except the r34 sedan. can somebody share a bit more info on this as im planning to swap all my r33 gtst running gear into a r34 sedan. cheers

[dori34]

^ R33 GTST coilovers fit into a R34 GT (non turbo) whether it be coupe or sedan

ive recently purchased G4 coilovers and fitted them up with no dramas.

[GTS4WD]

heres my latest dyno results,any coments please

WOW!!

COOL MAN!

CAN WE BE FRIENDS!?!

Sorry Mitch.. couldnt help myself..

[icred]

sorry if im saying somehting that has already been said

but from my knowledge there are 3 factors in increasing the power output of any engine.

these are factors of combustion

to create a fire you need 3 key elements...Fuel, oxygen, spark

so to create a bigger fire you increase any one of these

but by increasing only one element creates an unbalanced flame

to create a bigger and more efficient fire you must increase all 3 elements

therefore to increase power in an engine you must increase fuel, oxygen and spark.

fuel: bigger pump, bigger injectors, upgraded management to handle increase in fuel

oxygen: less restriction but to a certain degree. intake tract lengths can be played around with to altertorque shift and power band (read: hemi intake)

longer intake runners will create a more torqier engine, shorter intake runners will create more powerful engine.

spark: upgraded ignition eg: msd twinspark ignition system allows more timing without pinging.

great upgrade when changing the power band to encompass higher revs without sacrificing low end drivability.

the next thing to consider is response.

as previously mentioned alterations to heads, shaving, valves, valve springs, high comp lightened pistons

to get really good power out of an N/A engine you need revs or displacement.

revs: think F1. 2.8L v10? 14000rpm

lightweight pistons, short stroke rods, high compression heaps of power high in the rev range anything less than 8000rpm and it runs like shit

but when running more revs reliability decreases

displacement: one area that might not have been touched upon would be stroking. rb32de??

i know it can be done with L series engines but not sure if it would be a viable mod to rb30de.

would involve work on the internals and more specifically the crank. also dished pistons, playing around with bore and stroke.

when playing around with stroking a standard production model rb30e might not be able to be used as the bores maybe too close together.

nissan patrol rb30 block might be another option for longer stroke but not sure whether it would fit or whether it came with efi or whether it would be viable to turn into rb30de.

the r31skylineforums have debated this topic for ages and i know that someone has gone through the motions of extracting 200kw or more NA

keep in mind that the particular build in question was a no expenses spared operation.

i think i may have rambled on for too long

but hey my main point is that there are 3 key elements to extracting more power from any engine forced induction or NA

other than that the previous information is quite correct

again apologies for the long post

[Lithium]

heres my latest dyno results,any coments please

Its in the wrong area, its blatently turbocharged. There is nothing remarkable. There are RB30DETs based on NA RB30 bottom ends running around all over the place making >300kw @ wheels on the stock internals and you don't see any of those guys posting their NA dyno results in this thread. The reason is, they are no longer NA. Much like you.

Have people played around with decent cold air intakes, using ram air or anything?

Edited October 14, 2008 by Lithium

[paulr33]

if i had an n/a and i wanted more power or shall we say better acceleration i would do;

1) ecu tune

2) unretristrict the air intake

3) unrestrict the exhaust

4) diff gears

5) consider weight saving

6) consider engine displacement increase