The more I drive my car with headers, the more I feel like the car needs more air. Power has increased, no doubt about it, but low end response feels sluggish compared to when the 2nd stage intake opens up, at that moment there is a big surge in power. I wonder if keeping the 2nd stage intake opened would make a positive difference now, I know it didin't do it for me previous to the headers. What about an open element air filter? We all know that the JoeZ intake pipe performs better than any other intake on the market, but what about after headers? Has anyone done some testing?

The best way to find out would be taking the car to a dyno, but I don't feel like spending $100 just to satisfy my curiosity. Any thoughts on this?

 

juan there is a way to let the second intake stay open. I think a member posted the mod. try it out before you buy an intake. if that doesn't satisfy u get the joe z or hps. i'll try to do some testing as i will soon be joining you.

 

^^^ Yes, I tried it on my previous ISF and found out at the track that my times were 0.1s to 0.2s slower on the 1/8 mile (and about 2 MPH lower) keeping the 2nd stage opened. As soon as I put eveything back to normal my times improved. Now with the headers, and due to how strong the car runs as soon as the 2nd stage opens, I guess this cheap mod may make a difference.

 

I would have never thought of doing that little mod to it and see if that helps. Please tell us what your findings are. Thanks

 

I say take it to the track again!

 

Headers (if designed correctly) are "supposed" to create a scavenging effect that pulls more air quickly into the motor...almost like "supercharging" the motor if you will.

 

It has to do with your intake, we have 3 ISF with headers here, no sluggish here , all joez intakes, 2 sikky headers and ppe header. Y not swap intake with a local member and see what is the real problem ?

 

there is no problem just wanted to see if there is more of a gain now with headers involved with the intake.

 

Not really. You're way oversimplifying what happens. If they're designed correctly, they will promote better scavenging at certain rpm and throttle positions. It is impossible to pull air. All the headers do is put a low pressure area in the right place to create a greater pressure differential across the intake valve which encourages more air - but if there is a restriction upstream, there is no amount of encouragement you can do at the valve to get more air in the cylinder, and that's what Juanca is asking about.

A whole lot of this depends on the rpm and load. It's also possible there is a small range of operation where there is reversion going on and the exhaust isn't fully scavenged from the cylinder which leads to a dead spot in the powerband. The amount of R&D going into the header design determines a lot of this. Some of it can be done mathematically, some of it is inescapable because of some other limiting factor like the intake length and diameter or the valve size, or port size and shape.

Also, Juanca is in South Florida where humidity comes with warmer temperatures where California does not have significant humidity despite the warm temperatures, and finally, Florida has 93 octane and California's best pump gas is a very weak 91. So there's a lot more than just a simple "put an intake on it and all will be fine" to consider.

The flap does two things - increases the velocity and pressure drop across the airbox, but probably most importantly, it reduces intake noise for EPA testing in the most common range of operation. We all know from actual tests (thanks for doing this so long ago Juanca!) the engine makes less power if you disable the flap with the OEM intake and exhaust. We also know the CCS car has the intake flap completely disabled. So, there's plenty to think about.

 

^^^ I forgot about the CCS, you're right Lance, I'll give the flap mod a try again and I'll post my results.

As Evil said, my car has no problems, it's making more power throughout the whole powerband compared to OEM, I was just wondering if there were some low end ponnies left that I can get with a different intake setup. As I explained on my initial post, the car has a good surge of power once the second flap opens up, that left me wondering... I'll probably post some info after the weekend, if I have time to go to the track.

 

The ccs car has the flap completely disabled but also they have the ability to tune the cars engine so that also must come into thought.

 

I've been a big advocate of the DIY Flap Mod, and I dyno'ed my car to show that there was some benifit. The full thread is here.. Also here is the dyno comparison of the stock intake with the flap enable and DIY Flap Mod (run 7 is stock, run 9 is with the DIY Flap Mod):


I remember when Juanca took his car to the track and it showed a slower ET, but I always noticed a increase in power with my car (confirmed with my dyno's). But like Lobuxracer stated, this maybe due to multiple thing, but I suspect I've showed a increase in HP due to less restrictive exhaust (JoeZ) that I had where those who were noticing a decrease were with stock (more restrictive) exhaust. Anyway, give it a shot and take it to the dyno if you can and see if there is a measurable difference....Darshana S...

 

Dynos are OK, but for intake mods, nothing beats 1/8 or 1/4 mile. Trap speed never lies, and the car is moving so there are no fans or open hoods skewing the results. Besides, the dyno is only there to help us understand change and the belief is the change will make the car faster. If you measure the car directly on the road, there's nothing to guess about.

 

You're right Darshana, I had the muffler/cat delete as opposed as a full exhaust. I don't believe in seeing gains from an intake on a dyno, having the hood opened and a huge fan blowing cool air straight to the engine bay will give a reading that won't represent the day by day driving experience. As Lance said, trap speed will tell the truth.

 

Personally I would try the open flap thing just to see if the car feels more responsive on the road. I thought it was just unplugging the solenoid hose so that should only take a second to do and a quick drive around the block.

I don't have headers (or exhaust any more...for now) but I do notice that with the K&N intake (stage 2 flap disabled) I have a lull in the <2500 rpm range. People claim it's mostly heatsoak but I think it's the tune and stage 2 flap expectation to be honest. In the near 100-degree weather this week it def seems worse, but not by a large margin (but yes, noticeable). In cooler weather it's still there but the car just gets up quicker for obvious reasons.

Once past that "meh" area, the car screams (literally) and things are as expected though. To me it does feel more responsive in the upper RPMs than stock.

By no means is this the same as headers but I do think it's related to the "feel" of speed and possibly having a lower-rpm dull area based on changing air-flow on the stock tune in general. That's what I'm pondering right now anyway....