Modification of the NA engine

[rollakid]

With this kind of mod, I would advice him to do engine transplant ....much cheaper.

you mean transplat to a turbocharged engine? well yes, you can get all the power of the NA mod with a fraction of the cost by playing with turbo, but you will never get the satisfaction of squizing out every last hp out of that NA engine :D

how i wish there isn't any roadtax... so i can drive around in a 6 liter V8 everyday..

 

[sam1741]

use thinner head gasket increase compression
buy a stroker kit..

 

[llsaw]

"8. do anything to increase your compresion ratio, but with malaysian's ron97 fuel i don't see too much increasement in power without suffering from knocking"

I don't have any problems running on local fuel with 11.9 compression. It's all in the mapping but some Afterburn helps too..

 

[rollakid]

"8. do anything to increase your compresion ratio, but with malaysian's ron97 fuel i don't see too much increasement in power without suffering from knocking"

I don't have any problems running on local fuel with 11.9 compression. It's all in the mapping but some Afterburn helps too..

yes i do know that, tho i've only heard about 11.5 before, so thanks for your info :D but you can't deny that having low octane fuel is robbing precious horsepower especially for NA engine.

 

[llsaw]

97 octane fuel is not considered low.

 

[V8_nutter]

97 octane is low, suitable for on the road use only. If you have more than 11+ compression and high ignition, engine will knock like crazy.

 

[rollakid]

ron97 compare to US sure not low lar.. but compare to the rest of the more developped country sure on the lower side. me still dreaming of pumping 100 octane fuel in petrol station...

 

[V8_nutter]

"8. do anything to increase your compresion ratio, but with malaysian's ron97 fuel i don't see too much increasement in power without suffering from knocking"

I don't have any problems running on local fuel with 11.9 compression. It's all in the mapping but some Afterburn helps too..

If you're running 11.9 and engine is in "safe" condition meaning that your setup is "mild". Im running that compression wif avgas only, cause even V Power will knock like hell.

 

[V8_nutter]

ron97 compare to US sure not low lar.. but compare to the rest of the more developped country sure on the lower side. me still dreaming of pumping 100 octane fuel in petrol station...

If you feel 97 ron is OK, meaning your engine setup is mild.

 

[rollakid]

If you feel 97 ron is OK, meaning your engine setup is mild.

my current engine only need ron89 fuel lar~ the one sitting on the floor going in soon need 100

 

[V8_nutter]

100 is also low, but ok for normal use, not for high performance.

 

[llsaw]

"If you're running 11.9 and engine is in "safe" condition meaning that your setup is "mild". Im running that compression wif avgas only, cause even V Power will knock like hell"

Oops.. this probably means that your mapping is incorrect with too much advance or your dynamic compression is too high from running too small a cam profile/ports or your combustion chamber profile is inefficient with too much hot spots. My setup is as "mild" as 11.9 compression, 292/288 cams and race ported cylinder head with 180+bhp will allow me. Also if you're running a 4G93P head and inlet manifold you might want to disable the EGR along with the EGR code on the ECU as this will cause pinging at light throttle/cruising loads due to dilution of the intake combustion mixture.

 

[llsaw]

Unless your engine setup warrants it, running too high an octane fuel actually will at best result in no increase in power and at worse cause you to lose power. A fuel with a higher octane reading is often more difficult to combust efficiently.

 

[V8_nutter]

"If you're running 11.9 and engine is in "safe" condition meaning that your setup is "mild". Im running that compression wif avgas only, cause even V Power will knock like hell"

Oops.. this probably means that your mapping is incorrect with too much advance or your dynamic compression is too high from running too small a cam profile/ports or your combustion chamber profile is inefficient with too much hot spots. My setup is as "mild" as 11.9 compression, 292/288 cams and race ported cylinder head with 180+bhp will allow me. Also if you're running a 4G93P head and inlet manifold you might want to disable the EGR along with the EGR code on the ECU as this will cause pinging at light throttle/cruising loads due to dilution of the intake combustion mixture.

FYI my mapping is correct and im running high ignition with "maximum" advance possible (aka drag setup). Im not running 4g93p head and im not running that inlet as well, im on mivec head wif fabricated 4 throttle. No point you running 288/292 with mild ignition and safe mapping, dont make sense to me. Disable the EGR code ?? what wiring do you mention ? im not using stock wirings.

 

[V8_nutter]

Unless your engine setup warrants it, running too high an octane fuel actually will at best result in no increase in power and at worse cause you to lose power. A fuel with a higher octane reading is often more difficult to combust efficiently.

Low octane might suits your engine though, it wont suits mine. From 4000 rpm onwards, it will knocks like hell, suitable for low cam but not for my high lift cam.

 

[llsaw]

Bro,

The "mild" term I'm using was in jest. I'm not refering to any wirings either.

 

[V8_nutter]

You talking about hot spot, sometimes these things you can't avoid. What we can do is to minimize it, if your target is to win races you will tend to have a "lean" fuelling setup wif almost maximum ignition available, then to compensate this only race fuel can do.

 

[chris2000]

What V8_nutter is tuning the engine for maximum power with excessive advance ignition which will not be applicable for street use. Hence you will find 97 or even 100 octane fuel is low. Of course with high racing octane fuel you can run higher compression, more advance ignition and more boost if turbo. But it just not practical for a daily street driven car. Like a friend i know running 4G63 big turbine for daily use at 1bar on 92 octane pump gas. then on the dragstrip with a flick of a switch the whole fuel + ignition mapping change to 1.6 bar but this setup can only be use with full high octane drag fuel only!!

LLsaw's car is a Daily Driven putra running high static 11.9 compression with high overlap cams which reduces dynamic compression. He's car is properly tune and map for our regular 97 octane gas churning out all possible maximum power with his setup. So when a car can run properly with 97 octane does not mean it is not tune maximum!!!

So if it is a street daily driven car, and the car pink or knock, then it is definitely that the car is NOT TUNE properly to be daily driven for 97 octane! Just simple as that. Track and race car is total different ball game.

The Honda B18C-R engine, even stock is 11.0 compression, and I'm sure many members are running fine on regular 97 oct gas.

The MME race spec B18C-R engine are slightly higher at 11.2 to 11.5 comp, and it had no problem running on 97 oct for 12 hours non-stop race! The MSS race spec B18C-R engine are even higher at 12 to 12.5 comp with high overlap cams doing perfectly fine on 97 oct gas for short race!! It boils down how you tune and map your fuel + ignition on ECU for the 97 gas you using and the appropriate use of the car.

 

[llsaw]

Don't know what's a drag setup? Drag engines usually last 1-2 races before complete teardown and really not a good benchmark. Likewise the cooling of the engine is not up to it as the engine barely gets hot enough with heat soak in a 400m run. Static ignition should be left at 5 deg BTDC with dynamic advance depending on your engine setup and of course engine load. You control the dynamic advance via your ECU maps. On an engine with big profile cams giving a lot of overlap and with big ports bleeding off dynamic compression the static compression ratio should be increase else you will lose low end power.

Static compression ratio = measured compression when engine is not running
Dynamic compression = compression of the engine when the engine is running.

You can get by relatively high compression if you run big cams. That is the way to go. If you're pinging you're most likely running lean or you have inadequate cooling of the intake charge. Having an airbox with CAI setup or better still water injection into your inlet manifold will help in this aspect.

 

[llsaw]

"You talking about hot spot, sometimes these things you can't avoid"

Of course you can avoid or minimize these. This is where the skill of the porting and the cleanup and reshaping of the combustion chamber from manufacturing irregularities comes in..