PPE Headers actually work?
10-06-16, 09:05 PM
#17
I appreciate the offer however it will just be quicker and easier for me to take care of it on my end. I have already dropped the headers off elsewhere to get cleaned up and coated so I don't have them in front of me to share pics of what im talking about. The ports and area around the flange are pretty messy (especially for being tig welded?) and there are minimal marks from what I assume was someone running a flap wheel in and out real quick,. There is a noticeable lip on the inside of the collector where it should exit, seems like someone pushed the tube into the collector and welded it into place instead of making it fit properly. I am not sure if this can be fixed without cutting up the headers. The last main thing I would have done differently is that the spike in the collector (can't remember if it was just one or both) doesn't appear to be ideally aligned with the exit. One thing that you might be able to help me with is I had assumed there would be all the necessary gaskets as "gaskets" was listed in whats included. I was unable to find manifold gaskets, are these normally included?
We only include the header to exhaust gaskets. Most people reuse the metal gaskets between the header and engine. If you want to replace them, we recommend dealer gaskets.
10-23-16, 07:32 AM
#18
Well I have had a just a short amount of time to play with my car since installing these headers and I don't believe I have gained anything. I have many logged 40-60 and 60-80 pulls from before installing headers and I see no noticeable increase in maf readings and the times are not any better. I believe that the gain or lack of gain from these headers might just vary depending on the condition of the cats you lose when installing the headers. I have a fairly decent intake setup, as well as a decent custom dual exhaust setup so I don't believe gains from the headers are being held back by some restriction elsewhere. It is my opinion that the real problem and what is preventing these headers from performing well is the primary tube size is too large. I am betting that increase in exhaust velocity using either a 1 5/8" or 1 1/2" primary tube size would make a noticeable difference.
The following users liked this post:
2013FSport (01-06-18)
10-23-16, 05:27 PM
#20
Well I had to remove the battery to install the headers so yeah it was all reset. I want to get new o2 sensors as the car just hit 100k, just haven't yet. Im debating removing the cats from the OEM manifolds and swapping them back in to see if that works any better.
10-24-16, 08:23 PM
#21
Lexus Champion
You not going to feel any gain right away. It'll take about 1,000 miles of driving for ECU to relearn, and adjust more fuel and air to engine. You'll gain for sure because it's cat delete.
Last edited by MWIS350; 10-24-16 at 08:26 PM.
10-25-16, 09:48 AM
#22
I am not sure that is how it works. If the headers had any scavenging effect it would show in the maf readings and it doesnt. If the headers allowed more air through the engine then the car would actually feel stronger before the ecu adds more fuel as it would be running leaner. I noticed this with my intake and it took much less than 1000 miles before the ecu made corrections. I am still sure the problem is that the primary tube diameter is just too large which is just killing exhaust velocity.
10-25-16, 02:26 PM
#23
Mr. H
I know that PPE headers are engineered for each application. I have their headers on my ISF. However, if you're sure what you are saying is an issue, and believe me, I don't. Did you happen to notice that PPE makes headers of the IS250 as well as the IS350. Both are interchangeable as far as fitment goes. But, their tubes are different sizes, to conform to the displacement oil the engine. Maybe you would be happier with a set designed for the smaller engine. I doubt they would work well for you, but you never know.
Lou
I know that PPE headers are engineered for each application. I have their headers on my ISF. However, if you're sure what you are saying is an issue, and believe me, I don't. Did you happen to notice that PPE makes headers of the IS250 as well as the IS350. Both are interchangeable as far as fitment goes. But, their tubes are different sizes, to conform to the displacement oil the engine. Maybe you would be happier with a set designed for the smaller engine. I doubt they would work well for you, but you never know.
Lou
11-03-16, 07:45 PM
#25
someone please share how their car sounds with these headers. I have looked all over youtube and they make the whole exhaust sound raspy as hell. I have the F sport axle back with Megan Racing midpipe (retailing at $1800) and I'm debating on these headers but i want them to sound clean not ruin the exhaust note!
08-03-17, 07:27 AM
#27
Driver School Candidate
I modded my 08' IS350 back in 2011 with PPE Long Tube Racing Headers and Ceramic coating, plus Joez True Dual Exhaust with no cats, and JoeZ intake, and believe me it makes a big difference!
08-03-17, 04:22 PM
#28
Now you jist need a tune!
The following users liked this post:
Polo2is350 (04-01-20)
09-19-17, 08:16 AM
#29
I am not sure that is how it works. If the headers had any scavenging effect it would show in the maf readings and it doesnt. If the headers allowed more air through the engine then the car would actually feel stronger before the ecu adds more fuel as it would be running leaner. I noticed this with my intake and it took much less than 1000 miles before the ecu made corrections. I am still sure the problem is that the primary tube diameter is just too large which is just killing exhaust velocity.
How well are the supplied simulators working as Toyota has historically used the downstream O2 data to bias LTFT. And to your point, STFT are immediate and directly impact LTFT. The ECU should be done making its compensation over the first full range of operation. Agree 100%...
09-25-17, 02:08 AM
#30
@DickH are you saying the midrange took a big hit or 80% to WOT? I could see an oversized primary killing some of the midrange which is where most of the DD spend there days.
How well are the supplied simulators working as Toyota has historically used the downstream O2 data to bias LTFT. And to your point, STFT are immediate and directly impact LTFT. The ECU should be done making its compensation over the first full range of operation. Agree 100%...
How well are the supplied simulators working as Toyota has historically used the downstream O2 data to bias LTFT. And to your point, STFT are immediate and directly impact LTFT. The ECU should be done making its compensation over the first full range of operation. Agree 100%...
I do personally believe that the primary tube size is too large. Having 1 3/4 tubes for a maybe 300hp v6 just seems oversized. Exhaust flow is in the ballpark of 2.25cfm per hp and flow through a pipe is something like 115cfm per square inch. From here we can get approximate required size, keeping in mind too small is restrictive and too large slows exhaust velocity which is detrimental to any scavenging effect which is really where headers help make power. So lets see what we need for 375hp, which gets us around 320 at the wheel. I don't imagine anyone making more than this NA so this is a good best case scenario
375hp x 2.25 = 843.75cfm
843.75 / 115cfm = a required cross sectional are of ~7.33 square inches
7.33/6 = 1.22 square inches per header tube
16ga tube thickness = .0625
inside diameter of 1 5/8 primaries = 1.5 = cross sectional area of 1.77 square inches
inside diameter of 1 3/4 primaries = 1.625 = cross sectional area of 2.07 square inches
Of course there are flow losses due to the bends in the headers and the but the 1 3/4 primaries are still much larger than we need. I imagine that any gains that we do notice are more from freeing up where the oem manifolds might be too restrictive. I would be willing to bet that the headers for the is250 make better power on the is350 than the is350 headers.
If we do the same thing for the rest of the exhaust we see that the 7.33 square inch we see that dual 2.25in exhaust is slightly undersized at 7.1 square inches. Running a dual 2.5in exhaust gives 8.8 square inches which should cover more power than any of us will likely make. I have been debating contacting PPE and asking about getting some headers made with 1 5/8 primaries that will bolt up to a 2.5in exhaust setup made for an IS-F. I think this would make for a close to ideal setup.
As for the rear o2 sensors, I just unplugged mine and had the cel removed by OVT and have not had any problems. Reported AFR from the front o2 sensors appears to be where they should even a year later so I wouldn't worry about how well the sims work.
The following users liked this post:
2013FSport (11-21-17)