will i lose torque when going hi comp? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

driftkid316 · 09-30-2005, 11:01 PM

just wondering, if i were to go hi compression in the kade, would i lose any or alot of torque. just wondering because im considering going that route and dont wana lose the wonderful torqueyness of the KA. also, going hi comp, is it gona eat up my gas more like when turbocharging? would i have to up the injectors like in turbo cars also? thanks for the helph

wootwoot · 09-30-2005, 11:24 PM

Would gain torque since there would be more force per combustion event. Yes it will eat more gas and you are going to have to use premium.

ranisron · 09-30-2005, 11:30 PM

won't it be eating more gas above certain rpms?? i.e. 3500 rpm.

I can imagine shitty city gas mileage on a hi-comp.

wootwoot · 10-01-2005, 09:36 AM

It will eat more gas at every rpm

***S14DB*** · 10-01-2005, 11:47 AM

How will it "eat more gas?" Please, explain the physics to me wootwoot...

MakotoS13 · 10-01-2005, 11:51 AM

i seriously think it'd be more productive to build a supercharger kit than to build a high comp NA KA powerplant. you'd have torque and that wonderfull blower whine.

theicecreamdan · 10-01-2005, 12:23 PM

i had an alternator with an open diode and it sounded like i had a supercharger.

Andrew Bohan · 10-01-2005, 03:18 PM

my hi comp ka was fun until i blew it up. (about 150 miles once i got it running right).

it was definately more powerful than a stock KA, but not quite as powerful as a stock SR. maybe about 3/4 of the way between KA and SR. torque was maybe a little closer to SR than that.

wootwoot · 10-01-2005, 03:20 PM

I'm actually not to sure now that I started to think about it. A higher compression motor uses the same volume of air it is just compressed more before ignited. I was thinking "more air is compressed so more fuel must be added" which isnt true. My mistake, had never really thought to much about it before. Is that second thought right atleast?

***S14DB*** · 10-01-2005, 07:46 PM

Yeah, the higher compression the faster the fuel is burned. The faster the fuel is burned the more power you get from the charge. Displacement or Volumetric Efficiency changes are the only reasons you would add fuel. You are increasing the amount of Air getting into the cyl. so, you must increase the Fuel. Higher octane fuel burns slower to reduce chance of pre-ignition. but, also doesn't produce as much power.

Turbo/Supercharging increases the VE while artificially increasing the Displacement and CR.

09-30-2005, 11:01 PM	#1
driftkid316 Zilvia Member Join Date: Apr 2005 Location: corona, ca Posts: 198 Trader Rating: (2) Feedback Score: 2 reviews	will i lose torque when going hi comp? just wondering, if i were to go hi compression in the kade, would i lose any or alot of torque. just wondering because im considering going that route and dont wana lose the wonderful torqueyness of the KA. also, going hi comp, is it gona eat up my gas more like when turbocharging? would i have to up the injectors like in turbo cars also? thanks for the helph

09-30-2005, 11:24 PM	#2
wootwoot Post Whore! Join Date: Jan 2004 Location: sarasota florida biatch Age: 39 Posts: 3,850 Trader Rating: (0) Feedback Score: 0 reviews	Would gain torque since there would be more force per combustion event. Yes it will eat more gas and you are going to have to use premium. __________________ I'm from Florida so I'm probably a bit more strange than you

09-30-2005, 11:30 PM	#3
ranisron Zilvia Addict Join Date: Aug 2003 Location: Bloomington, IN Age: 43 Posts: 766 Trader Rating: (0) Feedback Score: 0 reviews	won't it be eating more gas above certain rpms?? i.e. 3500 rpm. I can imagine shitty city gas mileage on a hi-comp. __________________ U13 and S13 zilvia members are friendly

10-01-2005, 09:36 AM	#4
wootwoot Post Whore! Join Date: Jan 2004 Location: sarasota florida biatch Age: 39 Posts: 3,850 Trader Rating: (0) Feedback Score: 0 reviews	It will eat more gas at every rpm __________________ I'm from Florida so I'm probably a bit more strange than you

10-01-2005, 11:47 AM	#5
*S14DB* AFC #1 Join Date: Oct 2003 Location: 昨晩あなたのお母さんの家 Posts: 20,181 Trader Rating: (3) Feedback Score: 3 reviews	How will it "eat more gas?" Please, explain the physics to me wootwoot... __________________ Comments should be taken as Opinions not as Statements of Fact

10-01-2005, 11:51 AM	#6
MakotoS13 BANNED Join Date: Jan 2004 Location: Texas Age: 42 Posts: 4,205 Trader Rating: (0) Feedback Score: 0 reviews	i seriously think it'd be more productive to build a supercharger kit than to build a high comp NA KA powerplant. you'd have torque and that wonderfull blower whine.

10-01-2005, 03:18 PM	#8
Andrew Bohan Post Whore! Join Date: Apr 2003 Location: Ohio Posts: 8,331 Trader Rating: (2) Feedback Score: 2 reviews	my hi comp ka was fun until i blew it up. (about 150 miles once i got it running right). it was definately more powerful than a stock KA, but not quite as powerful as a stock SR. maybe about 3/4 of the way between KA and SR. torque was maybe a little closer to SR than that.

10-01-2005, 03:20 PM	#9
wootwoot Post Whore! Join Date: Jan 2004 Location: sarasota florida biatch Age: 39 Posts: 3,850 Trader Rating: (0) Feedback Score: 0 reviews	I'm actually not to sure now that I started to think about it. A higher compression motor uses the same volume of air it is just compressed more before ignited. I was thinking "more air is compressed so more fuel must be added" which isnt true. My mistake, had never really thought to much about it before. Is that second thought right atleast? __________________ I'm from Florida so I'm probably a bit more strange than you

10-01-2005, 07:46 PM	#10
*S14DB* AFC #1 Join Date: Oct 2003 Location: 昨晩あなたのお母さんの家 Posts: 20,181 Trader Rating: (3) Feedback Score: 3 reviews	Yeah, the higher compression the faster the fuel is burned. The faster the fuel is burned the more power you get from the charge. Displacement or Volumetric Efficiency changes are the only reasons you would add fuel. You are increasing the amount of Air getting into the cyl. so, you must increase the Fuel. Higher octane fuel burns slower to reduce chance of pre-ignition. but, also doesn't produce as much power. Turbo/Supercharging increases the VE while artificially increasing the Displacement and CR. __________________ Comments should be taken as Opinions not as Statements of Fact