Cold Air Intake , hit or miss?
08-04-14, 07:51 AM
#19
^^^^ This is exactly counter to the point of getting cold air into the engine.. You are now sucking 190 degree under hood air when lexus gave you that perfectly good scoop right near the hood latch front and center to breathe in cooler air from in front of the radiator.
08-05-14, 05:10 PM
#20
08-11-14, 06:23 AM
#21
^^^^ This is exactly counter to the point of getting cold air into the engine.. You are now sucking 190 degree under hood air when lexus gave you that perfectly good scoop right near the hood latch front and center to breathe in cooler air from in front of the radiator.
Between the headers, full stainless exhaust, and the intake, I have improved my gas milage. On road trips I get between 26 and 29 mpg.
08-12-14, 12:35 PM
#22
^^^^ This is exactly counter to the point of getting cold air into the engine.. You are now sucking 190 degree under hood air when lexus gave you that perfectly good scoop right near the hood latch front and center to breathe in cooler air from in front of the radiator.
Last edited by User 82021; 08-19-21 at 01:10 PM.
08-19-14, 06:55 AM
#23
Well, I see the scoop but the tube on the other end is not connected so hot under hood air is entering at the filter. A more relevent measure would be temp of intake air with your setup vs. intake air with the factory setup. Coolant temp is not relevant since it is maintained by the thermostat. And why not connect the tube back to a custom made filter box or remove that entire plastic assembly to get some cold air over the radiator and into the engine compartment. The point to this specific thread was examining the value of cold intake air.
As far as the rest of your mods. If efficiency was the goal, you will be churning through a bunch of miles to make back $600 headers + intake + exhaust system with a 2-3 mpg increase.
As far as the rest of your mods. If efficiency was the goal, you will be churning through a bunch of miles to make back $600 headers + intake + exhaust system with a 2-3 mpg increase.
08-19-14, 07:23 AM
#24
Looking at the PPE headers dyno is interesting. Yes, there is a 20 HP gain in the 5700 rpms but look at everything you loose on the low end. I'm almost willing to bet the tradeoff probably does not improve 0-60 times. 
Last edited by Lavrishevo; 08-19-14 at 09:10 AM.
08-19-14, 07:38 AM
#25
There isn't a single loss shown on that dyno, not sure what you're seeing.
It'd be more beneficial to see a dyno where they actually disabled the kickdown switch and started the run below 2krpms though.
It'd be more beneficial to see a dyno where they actually disabled the kickdown switch and started the run below 2krpms though.
08-19-14, 07:49 AM
#26
At about 4400 rpms stock is making 235 foot pounds of torque at the wheels. With headers they are at 195 or so. The additional power and torque are not there until over about 5300 rpms. That is a loss of a lot of low end power. Who wants to drive a LS430 between 5000 and red line to gain hp and torque?
Last edited by Lavrishevo; 08-19-14 at 08:36 AM.
08-19-14, 08:05 AM
#28
No, look at the rpm's to power ratio. Look at the trade off. Changes the motor a lot in my opinion. This is why tuning is so essential. I bet the curve would be a lot more linear if we could tune our cars.
Last edited by Lavrishevo; 08-19-14 at 08:18 AM.
08-19-14, 08:19 AM
#29
Indeed, compare bold to bold (HP), light to light (torque). Green and blue are before/after so there is no loss on the chart but it starts at 4,200 RPM which my LS430 rarely sees.
I'd like to see the plots 2000-4000 rpm where 99 % of my drving is done.
I'd like to see the plots 2000-4000 rpm where 99 % of my drving is done.
08-19-14, 08:32 AM
#30
The light colors is stock. The bold colors is with the headers. You need to compare bold to light at any given rpm. Green is torque. Purple is HP. The power curve I am sure would be very similar at lower rpm's. This is also common on intakes. No wonder nobody is doing this. Not worth the money at all...
Also, the chart can be deceptive. Stock at 5000 rpms is 242 lbs of torque. With headers max power is only really 4 lbs of toque more (246) then the stock system can generate. When you really look at the max power output between the two the gains are actually only about 5 lbs on the torque and HP with the headers. It's deceptive to compare at only a specific rpm for the gains. I'm not impressed. Another example on why without tuning your basically wasting your money.
Also, the chart can be deceptive. Stock at 5000 rpms is 242 lbs of torque. With headers max power is only really 4 lbs of toque more (246) then the stock system can generate. When you really look at the max power output between the two the gains are actually only about 5 lbs on the torque and HP with the headers. It's deceptive to compare at only a specific rpm for the gains. I'm not impressed. Another example on why without tuning your basically wasting your money.
Last edited by Lavrishevo; 08-19-14 at 09:09 AM.