PureDrifter

iTrader: (10)

any word on GS headers fitting the LS?

or will it be the same at flange rotating issues as the S&S?

JBrady

Should be the same as the GS4xx, rotated flange, differret angle, shorter by an inch or so.

User 82021

i know paul was working on fitting some on a gs400 after mine were done so there may be hope for you GS guys

PPEHeaders

iTrader: (4)

Yep, the GS will be here on Monday so we can get a direct fit version for the GS cars.

I just made a new thread that has some more info on the headers
https://www.clublexus.com/forums/per...-gs-ls-sc.html

JBrady

I am VERY pleased to see PPE creating headers. This is good news for everyone. That said the before/after dyno sheet posted needs a closer look to get better perspective.

Dyno runs typically have "peaks" and "valleys" that usually are smoothed out. Hard to see on the pic but looks like some smoothing is applied but noticeable peak/valley waves are present. What is normally considered is the average of the waves.

The screen shot has the dyno line placed at the peak power on for the header run is also on top of a "peak". It happens that that is also a "valley" for the before run. This changes the total gain by 3-4hp. Averaging would raise the before 1-2hp and lower the after power by 2-3hp. Not a big deal but worth noting as back to back dyno runs often differ by 5rwhp and often more. Also important is the conditions present. If the before run is a colder day than the after run or the humidity or the barometer is different the comparison is not as accurate even if correction factors are included due to the way our engines/CPUs respond to weather conditions.

As GSteg accurately noted the run was only from 4250rpm to 6100rpm. The stock engine rating has peak torque at 3400rpm. Hard to get dyno data down low due to the transmission shifting at WOT but important to realize that the gain/changes at lower RPMs are important to driver "feel".

The dyno posted does NOT have peak torque going from 203 to 223 but rather apx 228tq to 241tq. Maximum torque difference is apx 20 but peak difference is around 13tq.

No mention was made of other exhaust changes so I presume stock.

Per PPEs thread they chose 1.625" primaries and 2.5" collectors. It would be great to get solid data on how this size and design compares to the 1.5" sized primaries.

Again, great to see these on the market and I am sure more dyno data to come.

User 82021

yes the car is completely stock other than the headers

GSteg

iTrader: (15)

What does your butt dyno tell you about the low end?

User 82021

it is a definite increase. honestly i am surprised that they made that much of a difference.

Rock-a-Lex

iTrader: (4)

Guys...for your reference as far as gains with headers.

1st dyno graph - with Intake, exhaust (rear section), TM spark plugs and Apexi Neo

2nd dyno graph - with all mods listed above AND S&S headers (with a re-tune of the Apexi Neo)


***I dyno'd a 3rd time after I had my cats replaced; it yielded about 5whp LESS and 10WTQ LESS than my 2nd dyno because it was about 30 degrees WARMER out AND I had my heavy AS$ 19" wheels on. So, this obviously sapped some power up.

JBrady

On the PPE thread I was asked would it be worthwhile to change from the S&S headers to the PPE headers. Not wanting to hijack that thread I will answer here.

No.

I doubt there will be any noticeable power between the 2 designs in the 4000-6300rpm range.

From 2000-4000rpm my best GUESS is that the S&S will be SLIGHTLY better.

We only have one dyno of the PPE and that is on an otherwise stock LS430. We do not know what the specific conditions of each dyno (which is needed) and we will never be able to compare the low end power, response and part throttle dynamics with a dyno sheet.

From the one dyno sheet the PPE gained 19rwhp (227rwhp to 246rwhp) and 13rwtq (229rwtq to 242rwtq). While some/many people may think that dyno numbers are absolute more than a few of us that have been down this road understand that dyno numbers vary for MANY reasons. It is not uncommon to see 5rwhp or more on back to back runs of on the same car on the same dyno session and 10+rwhp variance is not unheard of.

The VERY well documented and multiple third party dyno and racing testing of the JoeZ dual exhaust for the IS-F was NOT enough when one customer found NO gain after an installation. Read thread here: https://www.clublexus.com/forums/is-...ower-gain.html

The bottom line is exhaust dynamics are very complex and even the REAL experts still debate the reasons for gains and losses. Both the S&S and the PPE headers are compromises. Both do a good job compared to the stock manifolds. I would LOVE to see THOROUGH back to back testing of both designs because I am a data nut.

I look forward to future test results.

TLcoats

iTrader: (11)

Bumpin this to see if there's any updates from PPE?

passnu2

iTrader: (33)

so according to what jbrady has posted the only true difference would be quality. I see that S&S had issues with the welds so this could be the reason to make the change. I havent read of any issues with the ISx50 members having any issues with PPE. I do agree that the power is going to be very similar between the 2 and I wouldnt make a change unless you are having issues with your current ones.

So what is the status of this GB? anyone else still interested in long tube headers?

JBrady

Actually what I said was until we have more data it is hard to say which design would make the most power. At this point my best GUESS is that the S&S design will have better low RPM power and response and that both designs will be VERY close in peak output... probably within dyno error. More importantly than peak power of 1-5hp will be responsiveness.

Cracking was a problem on the original design S&S headers which was resolved (AFAIK) by increasing tubing wall thickness and adding slightly more welding. Quality was not at issue. Cracking is common on exhaust manifolds and happens frequently to OEM manifolds as well as aftermarket. Short tube headers have less material to absorb heat expansion. PPE is a quality shop and we hope will have no issues with cracking but of course until a design gets thousands of miles of use it is VERY difficult to pre-guess problems. I do not know the thickness of the PPE tubing. Many headers use .049" (18 gauge) wall thickness while the original S&S used thicker .065" (16 gauge) tubing that was upgraded to the final .083" (14 gauge). Both the S&S and the PPE designs are mild steel with ceramic coating. The PPE uses 4-1 design with 1.625" primaries into 2.5" collectors while the S&S used 1.50" primaries, 1.75" secondaries into 2.5" collectors.

I see no reason to replace S&S headers with PPE unless some other issue is encountered. I also see no reason to run long tube headers for MOST Lexus applications.