Independent DYNO Proven results by "Caymandive" - no BS here!!
10-18-16, 07:12 AM
#286
Maybe I'm wrong, but he is asking about the intake filter, not tube. The aFe filter is NO DOUBT a better filer than the stock one. Much better design and air flow.
The tube on the other hand, has def been a long questionable subject on changing it out or leaving it stock. Mine is stock.... haven't changed it out because I'm not seeing the gains to cost ratio in my favor. Just not justifiable. With the option we have out here though, if I were to change it out, it would probably be HPS to get my money. Never hear anything negative about it with heat soak/hp loss, and people have actually seen 4-7whp gain (very minor, but still a gain) with it.
Of course the tuned intake from RR Racing has show much higher gain, but that's in conjunction with the tune....and I'm just reluctant to get ride of my stock 2 stage airbox....
Caymandive, have you brought it to there attention about all the problems you found?? Even if you don't want anything back from them, you need to make sure they know you found and experienced issued. Hell, they may be thinking you're a super happy customer right now and praising their guys for a "job well done" on your car. I say make a separate thread on your findings, frustration, experience. A lot of people have planned and already have gotten them to do the new v2 headers so people need to know so they can check their vehicles over to make sure there were no hack jobs done.
V.
The tube on the other hand, has def been a long questionable subject on changing it out or leaving it stock. Mine is stock.... haven't changed it out because I'm not seeing the gains to cost ratio in my favor. Just not justifiable. With the option we have out here though, if I were to change it out, it would probably be HPS to get my money. Never hear anything negative about it with heat soak/hp loss, and people have actually seen 4-7whp gain (very minor, but still a gain) with it.
Of course the tuned intake from RR Racing has show much higher gain, but that's in conjunction with the tune....and I'm just reluctant to get ride of my stock 2 stage airbox....
Caymandive, have you brought it to there attention about all the problems you found?? Even if you don't want anything back from them, you need to make sure they know you found and experienced issued. Hell, they may be thinking you're a super happy customer right now and praising their guys for a "job well done" on your car. I say make a separate thread on your findings, frustration, experience. A lot of people have planned and already have gotten them to do the new v2 headers so people need to know so they can check their vehicles over to make sure there were no hack jobs done.
V.
Yes I immediately contacted JE/SIKKY. See post number 267 in this thread. After I found all the problems I notified them and this was the response I received. "Wow, I'm sorry to hear that. I understand your frustration." There was no accountability for the shotty workmanship at all!
As for the intake/filter. In all my testing and runs at the drag strip I've never seen solid evidence of any benefits to running anything except for the stock intake setup. I've hit over 120mph in the quarter mile a few times on the stock intake/filter and that's enough reason to stick with what I know works fine. I've even tried running no filter on the dyno and at the strip and saw no gains.
Check out my AFE testing post here: https://www.clublexus.com/forums/is-...ml#post5781792
Last edited by caymandive; 10-18-16 at 07:16 AM.
10-18-16, 11:29 AM
#287
Pole Position
Kinda wish I didn't have the cats on my car at the moment for some apples to apples dyno testing, but the GESI cats claim no loss in power and from my experience with high flow cats the power can be a bit higher than without out on N/A applications. I remember when I had high flow cats installed on my old JOEZ exhaust. I picked up a tiny bit of power.
Can you explain the science further behind this, (because if so there would be no complaints from me
)?Thx
10-18-16, 12:11 PM
#288
My guess would be due to increasing/altering the exhaust piping diameter/design, therefore altering the flow characteristics, may have a negative effect on the exhaust scavenging. It's possible that by adding the cats it could optimize the scavenging ability thus increasing power output.
With forced induction, this wouldn't matter, but NA I could see it playing a role.
With forced induction, this wouldn't matter, but NA I could see it playing a role.
10-18-16, 12:18 PM
#289
I know that GESI claims that you lose no HP (which is awesome!), but curious as to why you would gain any HP on an N/A engine with high flow cats like what you described above with your Joe Z and picking up power???
Can you explain the science further behind this, (because if so there would be no complaints from me)?
Thx
Can you explain the science further behind this, (because if so there would be no complaints from me
)?Thx
Check out the link below on my pre/post cat testing.
https://www.clublexus.com/forums/is-...ml#post6015477
UPDATE: I have dyno testing scheduled for next Wednesday the 26th pending weather conditions.
10-18-16, 12:39 PM
#290
^^^^It's really not about back pressure, it's about flow. Any Impediment placed in the exhaust system, like a catalytic converter, will have a negative effect on power.
Read this:
http://www.dsmtuners.com/threads/exh...essure.168578/
Lou
Read this:
http://www.dsmtuners.com/threads/exh...essure.168578/
Lou
10-18-16, 01:41 PM
#291
^^^^It's really not about back pressure, it's about flow. Any Impediment placed in the exhaust system, like a catalytic converter, will have a negative effect on power.
Read this:
http://www.dsmtuners.com/threads/exh...essure.168578/
Lou
Read this:
http://www.dsmtuners.com/threads/exh...essure.168578/
Lou
10-18-16, 02:49 PM
#292
Pole Position
My guess would be due to increasing/altering the exhaust piping diameter/design, therefore altering the flow characteristics, may have a negative effect on the exhaust scavenging. It's possible that by adding the cats it could optimize the scavenging ability thus increasing power output.
With forced induction, this wouldn't matter, but NA I could see it playing a role.
With forced induction, this wouldn't matter, but NA I could see it playing a role.
I wish I were smart enough to be able to explain the science behind this, but in a nutshell N/A engines often require a bit of backpressure for optimal power. This could come in exhaust diameter, cats, bends, etc. Anyway I believe it may have something to do with scavenging, exhaust timing and exhaust flow velocity. I've seen gains on my old SIKKY/JoeZ setup with high flow cats and talking to a few others they've seen the same on N/A applications. I'm not saying in all cases high flow cats yield power as some truly are more restrictive for a balance of performance and excellent emissions, but high quality high flow cats on an N/A car can result in a slight bump or no loss in power.
Check out the link below on my pre/post cat testing.
https://www.clublexus.com/forums/is-...ml#post6015477
UPDATE: I have dyno testing scheduled for next Wednesday the 26th pending weather conditions.
Check out the link below on my pre/post cat testing.
https://www.clublexus.com/forums/is-...ml#post6015477
UPDATE: I have dyno testing scheduled for next Wednesday the 26th pending weather conditions.
^^^^It's really not about back pressure, it's about flow. Any Impediment placed in the exhaust system, like a catalytic converter, will have a negative effect on power.
Read this:
http://www.dsmtuners.com/threads/exh...essure.168578/
Lou
Read this:
http://www.dsmtuners.com/threads/exh...essure.168578/
Lou
So it's all about velocity and gas flow, this is where I think the GESI cats will do what they need to do and not lose any power as they have stated? Hopefully next week we'll find out if Cayman loses any power or gains power??
Here is the main quote of that post for some people who don't click on that link:
Since many people get confused about backpressure, scavenging, exhaust sizing, etc., I wrote this up for another board. I just did a quick cut and paste here, so enjoy...
There is a common misconception that engines need backpressure in order to run properly, generate low end torque, etc. That is simply untrue. Backpressure is a bad thing. Always. Take a look at a top fuel dragster...how much backpressure do you think those zoomie headers make? Very little, and those engines produce 6500 hp.
So, what is backpressure? Any fluid flowing through a pipe experiences drag on the walls of the pipe. This depends on a number of factors, including the diameter of the pipe, the smoothness of the inside of the pipe, the viscosity of the fluid, and the velocity of the fluid. This drag results in a pressure drop through the pipe. In order for the fluid to flow at all, the pressure on one end of the pipe must be higher than at the other. In an exhaust system, that pressure drop is what we refer to as backpressure. It's pretty obvious that the engine has to produce this pressure differential, so the less power it has to spend making pressure to push the exhaust out, the more power it can send to the wheels.
Given that exhaust pipes are pretty smooth, and that we can't change the viscosity (thickness) of the waste gas being forced through the pipes, we are left with basically 2 parameters we can have any control over: The pipe diameter and the gas velocity.
Unfortunately, the pipe diameter controls the gas velocity since the volume of gas is prescribed by the engine. So, we really only have one thing we can change. So, bigger pipes allow less pressure drop for a given volume of gas because the velocity is lower. The pressure drop (backpressure increase) is proportional the gas velocity squared, so if I double the gas velocity (by reducing the cross sectional area of the exhaust pipe by half) then I quadruple the pressure drop.
Well, there's an easy solution for that: Just make the exhaust pipe bigger. Bigger pipe, lower gas velocity, less pressure drop, so less backpressure. Wow, that was easy. After all, this is the way it's done for basically any type of commercial plumbing system. Need less pressure drop on a chilled water pipe or a natural gas line? Just make the pipe bigger.
But wait, there's a problem....Having a huge exhaust pipe has killed my low end torque!!! What's different? Oh, there's no backpressure!! Therefore backpressure makes torque!
Wrong.
An exhaust system is different than just about any other plumbing situation. How? Because the flow is pulsed, and this turns out to be a big deal. Every time a pulse of exhaust gas runs through the pipe, a strange thing happens: it as it passes, it has a little area of vacuum behind it. Just like a NASCAR stocker running around the track, the pulse generates a little bit of a vacuum behind it. In NASCAR, a driver can take advantage of another driver's vacuum by getting right behind him and driving in it. The wind resistance is drastically reduced. This is called drafting.
Well, how big the vacuum behind each pules is depends on the gas velocity. The higher the velocity, the bigger the vacuum the pulse has behind it.
Now, this means that I can "draft" the next pulse, just like in NASCAR. In NASCAR, it's called drafting, in an exhaust system, it's called scavenging. You've probably seen this term used when talking about headers, but the same concept applies in the pipe.
I get the maximum scavenging effect if the gas velocity is high, so the pipe needs to be small. By maximizing the scavenging effect, I help to pull pulses out of the combustion chamber, which means the engine doesn't have to work as hard to do that.
This has the most effect when there's a bunch of time between pulses...in other words, at low rpm. As the revs rise, the pulsed flow becomes more and more like constant flow, and the scavenging effect is diminished.
So, at low rpm I need a small pipe to maximize scavenging, and at high rpm I need a big pipe to minimize pressure drop. My exhaust pipe can only be one size, so it's a compromise. For a given engine, one pipe diameter will make the most overall power (i.e., have the largest area under the curve on a dyno chart).
So, the loss of torque has nothing to do with backpressure, and everything to do with gas velocity. So you need exhaust components that are not restricive (manifolds/headers, mufflers) and that are sized correctly for your application.
To further dispel the "backpressure is necessary" theory, try this if you want. If you have access to a vehicle with open headers, make a block off plate that will bolt to the collector. This plate should have only a 1" hole in it for the exhaust to flow through. That will give you PLENTY of backpressure, and zero scavenging. Then you can report back on how much low end power it has.
The one exception to sizing an exhaust is for turbo cars. Since the turbo is in the exaust stream, the gas flow spinning the impeller tends to come out of the turbo with the pulses greatly diminished. In this case, you can get away with running a larger pipe than on an equivalent HP N/A engine because you can't take as much advantage of the scavenging effect.
Last edited by MileHIFcar; 10-18-16 at 10:15 PM.
10-18-16, 03:41 PM
#293
Pole Position
You should try sourcing your own piece of aluminum, getting the degrees of bend and diameter just right, welding the two outlets at precisely the right place and angle (which is not an easy 90 degree bend), and then anodizing them. Oh, and don't forget to include the airbox and throttle body sleeves and clamps (which isn't nearly as easy as it sounds). And make sure it looks nice and smooth, too. Price that out and see what it costs you to make ONE before you post about something you've obviously never done before.
Javier
Javier
10-18-16, 04:08 PM
#294
This might need to be its own thread to get any attention. If this is the install job people expect to get with the new design, I doubt anyone is going to shell out this kind of money.
10-18-16, 06:05 PM
#295
^^^^It's really not about back pressure, it's about flow. Any Impediment placed in the exhaust system, like a catalytic converter, will have a negative effect on power.
Read this:
http://www.dsmtuners.com/threads/exh...essure.168578/
Lou
Read this:
http://www.dsmtuners.com/threads/exh...essure.168578/
Lou
Good read and you're right it's about flow. So my question back to you is, if the cats are sized right for the power output of the engine, are they even considered an "impediment?" Based on testing with the F in the past with the Random Tech cats they proved to not be an impediment to exhaust velocity/flow. The slight bump in power I saw could be a result of numerous variables, but the fact remains I sure didn't lose any power with cats in place. I'm going to reach out to my V8 engine building buddy who I was talking to the other day to see if he can give me a better explanation. Anyway, love the discussion.
Last edited by caymandive; 10-18-16 at 07:20 PM.
10-18-16, 08:26 PM
#296
Pole Position
Interesting............ so where is the best place to weld in the GESI cats?? I was thinking right after the secondary (downstream) O2 sensors that way I don't have to have a muffler shop move the O2 bung??? So basically just a little bit further down then where yours were welded in?
Is that an ok spot to weld them in?
Is that an ok spot to weld them in?
10-19-16, 04:02 AM
#297
Interesting............ so where is the best place to weld in the GESI cats?? I was thinking right after the secondary (downstream) O2 sensors that way I don't have to have a muffler shop move the O2 bung??? So basically just a little bit further down then where yours were welded in?
Is that an ok spot to weld them in?
Is that an ok spot to weld them in?
10-19-16, 09:21 AM
#298
Pole Position
Ok, thanks good to know. I like how they welded the extension for the O2 bung on the Joe-Z/Random Technology set-up.
My thought process was to weld them in behind the current position/set-up and have them be like the secondary cats on the stock exhaust which would still clean the exhaust stream and allow it to pass emissions testing. The only requirement at that point to avoid the CEL is the RR-tune or a conditioner/sim correct?
My thought process was to weld them in behind the current position/set-up and have them be like the secondary cats on the stock exhaust which would still clean the exhaust stream and allow it to pass emissions testing. The only requirement at that point to avoid the CEL is the RR-tune or a conditioner/sim correct?
10-19-16, 02:25 PM
#299
Lou
10-19-16, 02:42 PM
#300
IMHO, any cat is an impediment, because of the honeycomb media it is filled with. It has to affect flow, even if it's high flow. As you are probably aware I have MagnaFlow HiFlows in mine. I few years ago a friend and myself dynod on the same day. He had PPE Headers and a JoeZ exhaust along with a K&N Intake (No Cats). I had PPE headers, PPE Dual Mode Exhaust, the Magna flow cats, and a Takeda intake. He made 400WHP I made 393WHP. I chalked up the difference to the cats.
Lou
Lou
Yeah I remember and the small 7hp difference could be due to a number of different things to include car to car differences. My guess is the Magnaflow cats won't lose any hp either.