can anyone actually provide proof as to which - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

MarketPlayer · 05-27-2002, 03:02 PM

I have heard both arguments, but none of them ever really provided proof as to which is more efficiant for turbo and N/A!  From what i understand...the SOHC is better for lower boost b/c the the air's velocity is higher and creates more torque, and a DOHC is better for higher boost b/c it won't limit the flow of the air as much...  As for N/A I would say that it would be the same right?  Low rpm's (daily driver) SOHC would create more power, and higher rpm's would create more horsepower by flowing more air?  If i am off by a little or a lot please tell me, because i want to build up a turbo 240sx and a N/A 240sx, and need to know which model to buy!  If SOHC is better for N/A then i will build my 1990, but if DOHC is better then i will need to buy a 1991+ 240sx, and then will swap out the KA24e w/ a rb20det, and build the KA24DE.
thanks in advance,
-zac

whateverjames · 05-28-2002, 05:50 PM

DOHC is better either way because turbo kits are easier to find <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt='

'> this is coming from someone who has a SOHC.

MarketPlayer · 05-28-2002, 06:56 PM

I don't care about availability, just efficiency!

rubbersidedown · 05-28-2002, 07:15 PM

first of all, this topic doesn't belong in chat, it belongs in the tech section. i wonder why it hasn't been moved there already. Secondly, both engines are good. And in what way do you mean effecient? both engines have their good and bad points. Pick one and use it. Part of the fun of building up a car is finding out shit for yourself. Now i'm not saying to go into the whole process blindly, but when i mean is learn the basics and whatever else you can and then the rest is purely up to you. that's just my 2 cents.

MarketPlayer · 05-28-2002, 07:43 PM

ok, could someone please move this to the tech section?  By efficient i mean,  Is a DOHC going to make more power if all things are equal or will a SOHC, when going N/A?  And the same for turbo.  All i want to know is which setup is best, when building a naturally aspired engine?  Forget about the turbo...Just N/A...I have decided officially on the RB20det for my turbo engine.  Please someone provide so really good insight into this.  thanks
-zac

rubbersidedown · 05-28-2002, 09:10 PM

i say go w/ the ka24de, specifically from a '91 240sx. The '91 is known to have the more agressive cams and on top of that the ka24de is newer. I know that doesn't necessarily mean the engine is better but i think that a new model engine would be made to be a little better than the previous.

05-28-2002, 05:50 PM	#2
whateverjames Nissanaholic! Join Date: Jul 2001 Location: St. Louis Age: 45 Posts: 2,263 Trader Rating: (0) Feedback Score: 0 reviews	DOHC is better either way because turbo kits are easier to find <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=''> this is coming from someone who has a SOHC. __________________ 02 Blazer X - 90 240SX w/SR oh noes

05-28-2002, 07:15 PM	#4
rubbersidedown Zilvia Junkie Join Date: Aug 2001 Posts: 343 Trader Rating: (0) Feedback Score: 0 reviews	first of all, this topic doesn't belong in chat, it belongs in the tech section. i wonder why it hasn't been moved there already. Secondly, both engines are good. And in what way do you mean effecient? both engines have their good and bad points. Pick one and use it. Part of the fun of building up a car is finding out shit for yourself. Now i'm not saying to go into the whole process blindly, but when i mean is learn the basics and whatever else you can and then the rest is purely up to you. that's just my 2 cents. __________________ 1991 240sx coupe w/ ca18det Bone stock Purchased but not installed parts: HKS adjustable timing gears Electronic Oil Pressure Guage Apex'i Multichecker t3/t04b turbo Stainless Steel, top mount tubular manifold ARC bov 450cc injectors Spearco FMIC

05-28-2002, 09:10 PM	#6
rubbersidedown Zilvia Junkie Join Date: Aug 2001 Posts: 343 Trader Rating: (0) Feedback Score: 0 reviews	i say go w/ the ka24de, specifically from a '91 240sx. The '91 is known to have the more agressive cams and on top of that the ka24de is newer. I know that doesn't necessarily mean the engine is better but i think that a new model engine would be made to be a little better than the previous. __________________ 1991 240sx coupe w/ ca18det Bone stock Purchased but not installed parts: HKS adjustable timing gears Electronic Oil Pressure Guage Apex'i Multichecker t3/t04b turbo Stainless Steel, top mount tubular manifold ARC bov 450cc injectors Spearco FMIC

05-27-2002, 03:02 PM	#1
MarketPlayer Zilvia Member Join Date: Mar 2002 Posts: 251 Trader Rating: (0) Feedback Score: 0 reviews	I have heard both arguments, but none of them ever really provided proof as to which is more efficiant for turbo and N/A!  From what i understand...the SOHC is better for lower boost b/c the the air's velocity is higher and creates more torque, and a DOHC is better for higher boost b/c it won't limit the flow of the air as much...  As for N/A I would say that it would be the same right?  Low rpm's (daily driver) SOHC would create more power, and higher rpm's would create more horsepower by flowing more air?  If i am off by a little or a lot please tell me, because i want to build up a turbo 240sx and a N/A 240sx, and need to know which model to buy!  If SOHC is better for N/A then i will build my 1990, but if DOHC is better then i will need to buy a 1991+ 240sx, and then will swap out the KA24e w/ a rb20det, and build the KA24DE. thanks in advance, -zac

05-28-2002, 06:56 PM	#3
MarketPlayer Zilvia Member Join Date: Mar 2002 Posts: 251 Trader Rating: (0) Feedback Score: 0 reviews	I don't care about availability, just efficiency!

05-28-2002, 07:43 PM	#5
MarketPlayer Zilvia Member Join Date: Mar 2002 Posts: 251 Trader Rating: (0) Feedback Score: 0 reviews	ok, could someone please move this to the tech section?  By efficient i mean,  Is a DOHC going to make more power if all things are equal or will a SOHC, when going N/A?  And the same for turbo.  All i want to know is which setup is best, when building a naturally aspired engine?  Forget about the turbo...Just N/A...I have decided officially on the RB20det for my turbo engine.  Please someone provide so really good insight into this.  thanks -zac