Wat can I do to get more low end power??
02-17-2011, 08:59 AM
#1
Wat can I do to get more low end power??
I've got a 98 5spd.. And the car is quick but the power doesn't really kick in until around 3000 rpm.. I've got a warpspeed y pipe and it has a fresh tune up, but past that it's stock. I plan on doin a 00vi swap soon, but from what I've read that just boosts top end. Suggestions please...
02-17-2011, 09:53 AM
#3
02-17-2011, 11:46 AM
#6
I've got a 98 5spd.. And the car is quick but the power doesn't really kick in until around 3000 rpm.. I've got a warpspeed y pipe and it has a fresh tune up, but past that it's stock. I plan on doin a 00vi swap soon, but from what I've read that just boosts top end. Suggestions please...
02-17-2011, 11:48 AM
#7
while yes it does drop revs quickly, but if you're actually racing, you'll learn quickly how to solve that problem
02-17-2011, 12:04 PM
#8
Ok so next step will be the flywheel. Now my question is.. Obviously the fidanza would be the best option, but I saw an eBay one that was fairly cheaper. So the question is, is that gonna be one of those get what you pay for deals where it's gonna be something that I hbe to replace again soon? And also should I go with a stage 2 clutch while I'm in that neighborhood?
02-17-2011, 01:01 PM
#12
Go with a larger TB, install some headers, Port match all intake and exhaust mating surface junctions....add more ignition timing, install a NWP spacer kit, and lengthen you intake system slightly.....
02-17-2011, 01:44 PM
#13
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Join Date: Dec 2008
Posts: 162
02-17-2011, 02:21 PM
#15
where can these parts be had? obviously the port match is not a part to buy
02-17-2011, 03:48 PM
#18
port match the entire intake and exhaust to ensure uninterupted air flow...NWP spacers (we have you been?), larger Pathfinder TB, go with a Hybrid SRI featuring a 6"intake filter and velocity stack and adapter, 15" super lightweight wheels and a JWT ECU if not affordable a 2 degree advance from a local dealer and some headers......search it's all there!
I'm a believer in the 00VI IM, a lightweight flywheel accelerates just as fast as it decel's....So it not as important if this is a Mostly street ride
All this stuff is found if you search the classifieds or search for them.....the 4th Gen are awesome cars and if you have the money JWT would be the first thing I would do.....or the last thing if you're short on money...I have one on my 3rd and it's night and day when compared to the stock ECU!!!!
All this stuff is found if you search the classifieds or search for them.....the 4th Gen are awesome cars and if you have the money JWT would be the first thing I would do.....or the last thing if you're short on money...I have one on my 3rd and it's night and day when compared to the stock ECU!!!!
02-17-2011, 03:52 PM
#20
All this stuff is found if you search the classifieds or search for them.....the 4th Gen are awesome cars and if you have the money JWT would be the first thing I would do.....or the last thing if you're short on money...I have one on my 3rd and it's night and day when compared to the stock ECU!!!![/QUOTE]
yeah i thought of an ecu but i have a 99 so for me its not so easy
yeah i thought of an ecu but i have a 99 so for me its not so easy
02-17-2011, 08:06 PM
#24
unfortunately 4th gens dont work the same way 5th gens and up do. the advance can be done, but it goes away as soon as you turn the car off. with that being said, if yall want timing advances you gotta do it indirectly or with an EU or jwt or something like that.
03-21-2011, 11:28 PM
#26
You're up to date on ALL maintenance? Our cars are attention ****** when it comes to fuel/spark related things....
If you don't want any more bolt ons then work on making anything that turns lighter... EG. Crank Pulley, Wheels, Flywheel....
Last edited by aackshun; 03-21-2011 at 11:31 PM.
03-22-2011, 12:28 AM
#27
yea i am.. i have brand new NGK plugs, new coils, new fuel filter, and K&N drop in air filter.
And i dont mind bolt ons.. like i said i just bought the underdrive pulley... in the process of buying an 00vi...and im looking for an orger selling a fidanza but as far as my wheels... i love my g35s. i dont think im ready to get rid of them yet.
And i dont mind bolt ons.. like i said i just bought the underdrive pulley... in the process of buying an 00vi...and im looking for an orger selling a fidanza but as far as my wheels... i love my g35s. i dont think im ready to get rid of them yet.
03-22-2011, 12:32 AM
#28
yea i am.. i have brand new NGK plugs, new coils, new fuel filter, and K&N drop in air filter.
And i dont mind bolt ons.. like i said i just bought the underdrive pulley... in the process of buying an 00vi...and im looking for an orger selling a fidanza but as far as my wheels... i love my g35s. i dont think im ready to get rid of them yet.
And i dont mind bolt ons.. like i said i just bought the underdrive pulley... in the process of buying an 00vi...and im looking for an orger selling a fidanza but as far as my wheels... i love my g35s. i dont think im ready to get rid of them yet.
... but right now i have my blacked out stock 16s on the front and the staggered g35s on the back...
03-22-2011, 06:21 AM
#30
The two main ways to increase torque (more commonly referred to as low end power when speaking in terms of relatively low engine speeds) are to get more air into the cylinder (bigger boom), and time the spark so that as the gases in the cylinder are expanding after ignition, they reach their maximum pressure just as the crank shaft is 90 degrees relative to the connection rod (better mechanical advantage).
The thing that complicates engine tuning is that for a given engine speed, the flow dynamics of the intake and exhaust gasses will be different than at any other speed. For low engine speed, you want to keep the velocity of those gases high to increase the charge efficiency in the intake, and the scavenging effect in the exhaust. This helps get more air into the cylinders. For high engine speeds, you also want these velocity's to be high, but the problem is the volume of gas is much, much greater as well. So if your intake and exhaust remain constant, you must make a trade off somewhere. To tune an engine to perform best in the lower rpm range, the intake piping should be relatively long, and the exhaust piping relatively narrow. Think cold air intake, and stock exhaust diameter. Both should be free flowing as well - think port matching and aftermarket y-pipes.
Another way to get more air molecules into a cylinder is to lower the intake temperature (make the air more dense). This is where the NWP spacers come into play, especially with the vq30 USIM, which is made of aluminum, a very good conductor of heat. You can also physically force more air into a cylinder with a turbo or super charger, but these setups can be expensive and maintenance intensive.
Spark timing needs to be tuned to obtain maximum cylinder pressure when the connecting rod and crank shaft are 90 degrees relative to each other. This is what the Emanage Ultimate is for, though I believe you can advance timing using a VAFC as well by tricking the ECU and causing it to use different cells in the timing map. There is an EU on sale right now in the classified for a good price. This tuning is most effective on a dyno. You can also set your air fuel ratio using the EU, which can make combustion more efficient, by also allows you to control cylinder temperatures somewhat to achieve more spark advance. You can have too much advance, though. Consider a cylinder in which the combustion gasses reach maximum pressure after the connection rod and crank shaft pass 90 degrees relative to one another.
Lightening anything that spins is a good way to "unlock" power that was used before to change the speed of the spinning object. If your flywheel weighs 20 pounds, it will take twice as much power to increase its speed as it would take to increase the speed of a ten pound flywheel the same amount in the same span of time. This is where light weight flywheels and light weight wheels come into play. An old adage in racing is one pound taken off any rotating part equates to two pounds taken off any static part. While not physically accurate, the point is that taking weight off the spinning parts of your car will absolutely make the car feel more powerful than the same amount of weight taken off any non-spinning part.
I think the bottom line with the VQ30 is that unless you want to use forced induction (turbo/supercharger), to get good power naturally aspirated, you need to get the rpms high and have the engine properly tuned for high rpms. The main limiting factor here is the displacement, and there isn't much you can do about that except moving to a bigger engine (VQ35).
The thing that complicates engine tuning is that for a given engine speed, the flow dynamics of the intake and exhaust gasses will be different than at any other speed. For low engine speed, you want to keep the velocity of those gases high to increase the charge efficiency in the intake, and the scavenging effect in the exhaust. This helps get more air into the cylinders. For high engine speeds, you also want these velocity's to be high, but the problem is the volume of gas is much, much greater as well. So if your intake and exhaust remain constant, you must make a trade off somewhere. To tune an engine to perform best in the lower rpm range, the intake piping should be relatively long, and the exhaust piping relatively narrow. Think cold air intake, and stock exhaust diameter. Both should be free flowing as well - think port matching and aftermarket y-pipes.
Another way to get more air molecules into a cylinder is to lower the intake temperature (make the air more dense). This is where the NWP spacers come into play, especially with the vq30 USIM, which is made of aluminum, a very good conductor of heat. You can also physically force more air into a cylinder with a turbo or super charger, but these setups can be expensive and maintenance intensive.
Spark timing needs to be tuned to obtain maximum cylinder pressure when the connecting rod and crank shaft are 90 degrees relative to each other. This is what the Emanage Ultimate is for, though I believe you can advance timing using a VAFC as well by tricking the ECU and causing it to use different cells in the timing map. There is an EU on sale right now in the classified for a good price. This tuning is most effective on a dyno. You can also set your air fuel ratio using the EU, which can make combustion more efficient, by also allows you to control cylinder temperatures somewhat to achieve more spark advance. You can have too much advance, though. Consider a cylinder in which the combustion gasses reach maximum pressure after the connection rod and crank shaft pass 90 degrees relative to one another.
Lightening anything that spins is a good way to "unlock" power that was used before to change the speed of the spinning object. If your flywheel weighs 20 pounds, it will take twice as much power to increase its speed as it would take to increase the speed of a ten pound flywheel the same amount in the same span of time. This is where light weight flywheels and light weight wheels come into play. An old adage in racing is one pound taken off any rotating part equates to two pounds taken off any static part. While not physically accurate, the point is that taking weight off the spinning parts of your car will absolutely make the car feel more powerful than the same amount of weight taken off any non-spinning part.
I think the bottom line with the VQ30 is that unless you want to use forced induction (turbo/supercharger), to get good power naturally aspirated, you need to get the rpms high and have the engine properly tuned for high rpms. The main limiting factor here is the displacement, and there isn't much you can do about that except moving to a bigger engine (VQ35).
03-22-2011, 07:51 AM
#31
I think the bottom line with the VQ30 is that unless you want to use forced induction (turbo/supercharger), to get good power naturally aspirated, you need to get the rpms high and have the engine properly tuned for high rpms. The main limiting factor here is the displacement, and there isn't much you can do about that except moving to a bigger engine (VQ35).
What is your definition of good power? Cause in the world of motors neither motor makes good power..... Decent at best.
There are tons of motors making great power at the low end, it's all about where your peak VE is, on our motors Nissan intended it to be around 4.5k, you can tune (modify) your power band anywhere you want, just how much $$$ and time are you willing to put into it? Don't just fall for the Honda philosophy, Screw TQ, make HP. Shelby said it best, TQ wins races, HP sells cars.
Last edited by aackshun; 03-22-2011 at 07:54 AM.
03-22-2011, 09:09 AM
#32
Wheel diameter alone will not affect performance one bit.
03-22-2011, 10:56 AM
#33
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I think the bottom line with the VQ30 is that unless you want to use forced induction (turbo/supercharger), to get good power naturally aspirated, you need to get the rpms high and have the engine properly tuned for high rpms. The main limiting factor here is the displacement, and there isn't much you can do about that except moving to a bigger engine (VQ35).
OP, If u still got stock wheels then i wd say to try those out and see how the car responds.
03-22-2011, 11:02 AM
#34
My scope was limited to an N/A VQ30de(k). "Good power" means 90-100 hp per liter with a nice smooth power curve from about 4.5k up. Even if the VQ30 had a peak VE at 2000 rpm, it still is only 3 liters, and you can only get so much boom from 3 liters.
03-22-2011, 11:22 AM
#36
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The point of a car engine is to power and drive a car, not to make power.
03-22-2011, 11:30 AM
#38
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Location: Worcester, MA
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I think the problem u have is that your exhaust is setup to be high flowing up top. What kind of exhasut system u got?
03-22-2011, 11:34 AM
#40
Dude that's totally doable. 270 WHP VQ30DEK. 100 hp per liter is brake horse power, not wheel horsepower. Maybe I should have specified.