How does a 4 cylinder keep up with a V8??
08-03-2009, 07:37 PM
#21
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She's a little faster than stock now 
When you say gain psi do you mean above ambient air pressure?
, I'm not sure what psi is or how it relates. kinglt-1 was refering to increasing psi levels, and therefore the displacement of the engin.I'm guessing it all related to forced induction, and the quantity it's being forced??
And I'll second guess n2o being cooler increases psi. But I could be well off track with that!
Hmm, I need to spend more time on 'how stuff works.com'!!
08-03-2009, 07:56 PM
#22
On The Tree
Err,
, I'm not sure what psi is or how it relates. kinglt-1 was refering to increasing psi levels, and therefore the displacement of the engin.I'm guessing it all related to forced induction, and the quantity it's being forced??
And I'll second guess n2o being cooler increases psi. But I could be well off track with that!
Hmm, I need to spend more time on 'how stuff works.com'!!
08-03-2009, 08:19 PM
#23
Err,
, I'm not sure what psi is or how it relates. kinglt-1 was refering to increasing psi levels, and therefore the displacement of the engin.I'm guessing it all related to forced induction, and the quantity it's being forced??
And I'll second guess n2o being cooler increases psi. But I could be well off track with that!
Hmm, I need to spend more time on 'how stuff works.com'!!
FI forces more air into the motor which of course means more oxygen wich is necesaary to burn more fuel resulting in more power.
N02 is 1 part N and 2 parts O so it is simply a different method of getting more oxygen into the motor accomplishing the same thing. BTW straight oxygen into the motor would cause catastrophic failure /melted pistons etc... This is an oversimplification but should be start....
Last edited by SOMbitch; 08-03-2009 at 08:20 PM. Reason: spellin
08-03-2009, 08:21 PM
#24
Err,
, I'm not sure what psi is or how it relates. kinglt-1 was refering to increasing psi levels, and therefore the displacement of the engin.I'm guessing it all related to forced induction, and the quantity it's being forced??
And I'll second guess n2o being cooler increases psi. But I could be well off track with that!
Hmm, I need to spend more time on 'how stuff works.com'!!
08-03-2009, 08:55 PM
#25
[QUOTE=taws6;12013439]
Err, , I'm not sure what psi is or how it relates. kinglt-1 was refering to increasing psi levels, and therefore the displacement of the engin.
I'm guessing it all related to forced induction, and the quantity it's being forced??
And I'll second guess n2o being cooler increases psi. But I could be well off track with that!
Hmm, I need to spend more time on 'how stuff works.com'!![/QUOTE ]
psi= boost! The more boost you add to an engine, the more air it flows, wich equals more power. Its all about air flow(cfm). The more (cfm) you flow the more power you make. The reason why you see 4cyl cars with turbos, is simply because they need the turbo to flow the cfm of air required to make that certain power level. A 2.5 in naturally aspirated form can not flow the volume of air rquired to make 305 hp(in a streetable manner). So add 14psi of boost via a turbo to the 2.5 litre and that will increases the volume of air moving thru the engine to make 305hp and keep it streetable. So In theroy a 2.5 litre needs around 14psi boost to flow the volume of air a stock ls1 does. Bigger Displacement is always the best way to go imo. You can make the same amount of power as a smaller motor on lots of boost and be alot more reliable when doing it. Also it will have alot better power curve. Meaning: more power in the lower rpms.
Err,
, I'm not sure what psi is or how it relates. kinglt-1 was refering to increasing psi levels, and therefore the displacement of the engin.I'm guessing it all related to forced induction, and the quantity it's being forced??
And I'll second guess n2o being cooler increases psi. But I could be well off track with that!
Hmm, I need to spend more time on 'how stuff works.com'!![/QUOTE ]
psi= boost! The more boost you add to an engine, the more air it flows, wich equals more power. Its all about air flow(cfm). The more (cfm) you flow the more power you make. The reason why you see 4cyl cars with turbos, is simply because they need the turbo to flow the cfm of air required to make that certain power level. A 2.5 in naturally aspirated form can not flow the volume of air rquired to make 305 hp(in a streetable manner). So add 14psi of boost via a turbo to the 2.5 litre and that will increases the volume of air moving thru the engine to make 305hp and keep it streetable. So In theroy a 2.5 litre needs around 14psi boost to flow the volume of air a stock ls1 does. Bigger Displacement is always the best way to go imo. You can make the same amount of power as a smaller motor on lots of boost and be alot more reliable when doing it. Also it will have alot better power curve. Meaning: more power in the lower rpms.
Last edited by kinglt-1; 08-03-2009 at 09:04 PM.
08-03-2009, 11:12 PM
#26
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ding ding ding.
I would like to see the MPG differences between a ls1 that runs 11.5 compared to a Honda that runs 11.5 and last. I would say the ls1 would definatly last longer, and maybe even get batter MPG if it is a stick
I would like to see the MPG differences between a ls1 that runs 11.5 compared to a Honda that runs 11.5 and last. I would say the ls1 would definatly last longer, and maybe even get batter MPG if it is a stick
08-03-2009, 11:46 PM
#27
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GM rated early ls1 f-bodies at 305 hp at the crank. that was an underrating, but that was the rating. not wheel hp, crank hp. In reality, a4's dyno around 280-290 and m6's dyno 300+, stock.
08-04-2009, 04:52 AM
#28
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Wow, I learn more everytime I get on here.
Before I got on this forum, I had problems changing a tire, now I feel no worries, even confident about my upcomming header swap 
Thanks for taking the time to explain psi to me
Another saying I keep hearing and now understand 
I just wonder how many local 'car guys' I'll confuse telling them on average my car runs at 14.7 psi ......
Before I got on this forum, I had problems changing a tire
, now I feel no worries, even confident about my upcomming header swap Thanks for taking the time to explain psi to me
better power curve. Meaning: more power in the lower rpms
I just wonder how many local 'car guys' I'll confuse telling them on average my car runs at 14.7 psi ......
08-04-2009, 07:14 AM
#29
Lighter cars = a more favorable Wight to HP Ratio and in most races such as "Ricing" from a roll, 85% of suspension and driving ability is thrown out the window. AWD is a curse and blessing, it helps those who cannot hook, the ability to put down some sort of reasonable 60 foot, but at speed AWD is a Parasite on HP.
If I were racing a High output turbo car, I would roll it to the line, let him click the stage, and I would sit on the line and let him burn his car to the ground, or over heat the engine so much that they drop off.
If I were racing a High output turbo car, I would roll it to the line, let him click the stage, and I would sit on the line and let him burn his car to the ground, or over heat the engine so much that they drop off.
08-04-2009, 01:26 PM
#32
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kinda just skimmed through the thread so I dont know if its been stated or not, but dont forget... HP is a function of RPM. An engine with less/smaller moving parts will inherently have less moment of inertia. This means that a smaller engine can *typically* spin at a much greater rpm safely. 300 hp @ 5800 rpm is not the same thing as 300 hp @ 7500 rpm. In this case torque would be a much better number when comparing the two cars.
08-04-2009, 03:28 PM
#33
I don't think anyone mentioned this yet, but how about the simple fact your car is 8 years old already. This is a 2008 STI your talking about running against a 2001 Trans Am, just think of any new GM V-8 400hp 505hp granted they aren't 5.7's but they are V-8s. I always tell people after a race man sucks that my 11 year old car with 130,000 miles just kept up with your brand new 35,000 dollar car doesn't it?
08-04-2009, 04:03 PM
#34
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Yes, it's good to know that even now LS1's can still beat most things on the road, and cost ALOT less. Best HP/$ car ? = LS1 90% of the time 
Last edited by taws6; 08-04-2009 at 04:23 PM.
08-05-2009, 05:15 PM
#35
Launching!
08-05-2009, 06:29 PM
#37
Power to weight, little motors rev to 10-13k rpms, spin faster- cause less recipcating mass, NAZZZZZ for them, boost, they have low friction rings or stock atleast. Tiny tires. O and most of them have the DOHC set where they can use higher lift cams, where we have cam in block and are restricted to a limited size- cam jorunals. O better yet they have VTEC, or a simalar valve altering lift.
08-07-2009, 05:16 PM
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Thought I would just chime in. I got a 91 Eclipse GSX for some carpentry work I did. Put a new head(stock), header, 16G turbo, safc1, hard piped the whole turbo system,bigger intercooler, bigger injectors and had it tuned. 313hp at 18 PSI boost. After about 2 weeks I blew the head gasket. Sold car to some kid and got a 95 T/A. Kid I sold car to fixed headgasket and I raced him with the 95 T/A. WOW did that car pull. Got me by about 2 carlengths from a roll to 120 ish 
. Wish I could find him now that I got a 02 Firehawk. I'd spank his ***.
I'm no ricer but sometimes a 4cyl turbo car will woop you. It's all about the money... I sank $3000 into that Eclipse and it turned out to be a pretty quick car. I was wasting Mustangs with it.
. Wish I could find him now that I got a 02 Firehawk. I'd spank his ***. I'm no ricer but sometimes a 4cyl turbo car will woop you. It's all about the money... I sank $3000 into that Eclipse and it turned out to be a pretty quick car. I was wasting Mustangs with it. 