Damn! And I had my hopes up for another set

 

This is why I have PZeros. I was told they have to set the line up specifically for the 305 width and so they only do limited numbers of runs. I tried several different places.

 

Concerning FVD headers: stock and FVD headers were measured in overboost mode on dyno?

( relatively big loss with FVD headers)

 

Did you do a calibration for race fuel as well on the stg 2+?

 

This is a question for Tom to answer. I certainly asked for one as I use MS109 at events. Just don't have the car back yet. I know that my results were on 93 octane.

 

wrs...I understand where you're coming from, I really do. I'm not sure what else I can say to explain to you that we TRIED VERY HARD to get some positive results from the headers. We didn't just slap them on, do a couple dyno runs, and call it a day. We spent a lot of time on the dyno revising the tune, adjusting the tune, and attempting to write custom software to take advantage of the performance gains they were advertised to offer. We did this because that is what the customer asked, and that's what he was paying for. So that's reason #1 that we wanted to see positive results.

Reason #2 that we wanted to see positive results is because we currently don't offer a header solution for the 991 Turbo, and I would have LOVED to save the time and money that we'll need to put into making our own. If the their parts worked as advertised, I would have GLADLY bought them directly from them and made them a part of our package.

I'm not sure what else I can say that will satisfy you at this point.

Yes, we did. He'll have both a 93 octane pump gas tune, as well as a tune for 100 octane or higher race fuel. The majority of the testing we do is with 93 octane since that represents the most common real-world driving condition for most of our customers.

 

I think the FVD headers do work as advertised because they are not advertised with a GIAC tune. I think you can understand why I say that makes a difference? I know that FVD is free to come on this board and defend themselves and since I have talked to the owner on the phone, I know they follow these discussions and they could but they don't for whatever reason. I think if you are going to post this kind of stuff and let your customer believe the product he bought is inferior, then maybe you owe it to FVD to have a public discussion about this. There are plenty of users who would like to know now if headers are bad in general and FVD in particular. What data is there to support that notion because it's now been raised in this thread and another thread. I personally know another user who basically has my setup but in Fabspeed and he is very happy with it on his 2015TTS and I can testify his car is fast from having run with him at COTA.

The other thing I think you should do is to address my comments about the RPM range where the headers seem to show lower hp and tq. The car doesn't run in that range in that gear under most conditions, the driver would have to force the car to run there because that isn't an optimal running condition for the car. You would get your *** handed to you in a roll race if you started from those rpms in that gear so does that drop in HP below 5000 rpm in 4th gear matter at all if the car is never running in that range?

In the higher RPMs, at the shift point between 5200 and 5700 rpm (99-109mph), the FVD headers show higher power and that is actually a very relevant operating point in the profile of the car on the track. What is the margin of error in your hp and tq numbers because above 5000 rpm, there isn't much difference in the two graphs and there are areas where the FVD headers produce more power but that was never mentioned in either your or SDG or _shifter comments. I would think you at least could address that.

Maybe what you really need to do if you are going to evaluate the performance of the car is produce dyno charts in the relevant gears, i.e 1,2,3,4,5. The top gears don't matter much at all but the first three gears are critical and they are not included in your dyno data. I honestly think that dyno data in the 1:1 gear are misleading. On the m5 it's 5th gear and I think a lot of people don't realize how little they use that gear but oh well, it's a sales pitch or it's useful information, which is it?

 

I invite you to attempt an accurate reading on my Mustang dyno in 1st gear in any car.

 

Well then I suppose someone was only to add one single modification to their car, then these headers would be it. But most people don't start with headers, or stop at headers. They start with exhaust, software, etc. FVD is free to come and offer their opinion or add to the discussion, so how do I owe them anything? I simply posted our results...sorry they're not what you (or anyone else) wanted to hear. Is it all headers in general, or just these? I don't know. I can only speak to the results we have tested and verified here at our facility. I can also tell you that we ditched our header program early on because of the same results....do the math on that one. The only reason we're revisiting our own headers at this point is because we're running larger VTG's on our car and it's at that stage where we believe that a well designed header may potentially help. Or maybe it won't...we'll see soon enough.

Asking to dyno in different gears will not prove your point, you're misunderstanding how dyno's work. What gear you're driving in does not change the power output characteristics of the engine, it simply changes the ratio at which that power is delivered to the wheels. It may feel faster or more powerful in 3rd at a certain rpm then it does in 5th gear, but that has absolutely nothing to do with the how the engine is producing power, it's all because of gearing. The engine's output curve never changes, no matter the gear. The only way to accurately measure that output using a dyno is to use 4th gear (or the closest 1:1).

LOL...I'll add second or third to that in most cases.

 

Actually you posted results without really explaining them. You have no explanation for why the headers would do this just that they seem to. You haven't posted results with headers and exhaust only, actually no one has that I am aware of and that is one configuration that a lot of people would be interested in just because of the concerns about what damage tunes of any kind can do to a car. Not that they do but some people are skittish about them. I know that if I had kept the M5, the Dinan piggyback was coming off because of all the trouble I had with the car after putting it on. I would have liked to have dyno data for just the downpipes, exhaust and CAI that I put on the car but there wasn't any posted and I couldn't find a dyno to get one done for the car. So far, the FVD piggyback seems to have helped and not hurt my car. I don't need a special file for race gas, the tune picks it up and the results are nearly instantaneous when the higher octane gas is mixed in. I like that about their piggyback. If their headers are limiting my performance on the track and at the strip, I would like to know why and be sure about it before I pay money to have them taken off.

So you tried to fabricate your own headers and had poor results on the dyno?


That is a change I am probably not willing to make, it takes the car too far from OEM for me. Even the intercoolers seem a step beyond for me.

Well I know basically how they work and I don't think my understanding of dyno's is the issue. I think what you are saying is that the drivetrain power response curve is the same in all gears which is not what I would have expected. However, I am not very knowledgeable about power response curves for cars so I will withhold any comment on that issue.

So now, back to accuracy, you didn't address my question about margin of error nor have you addressed the operating range issues I raised. Again, after first gear, the RPMs at which the headers subtract power won't be used at the track or in a drag race, right?

Would you mind addressing the issue of shift points and where and how this loss of power is going to manifest itself? I ask you this because it's important. If this loss of power is basically insignificant, then maybe the headers do provide a benefit you are overlooking.

I am trying to determine if I should remove my headers for better performance and from my analysis, the dyno chart doesn't provide enough data to lead me to conclude the headers need to be removed. They also add to the sound of the car and of course irrespective of performance, that is something I am interested in. I know they improved the sound because I added them after the exhaust.

 

Why is that and what is the accuracy of these devices in the first place? I think that is an important consideration. So are the plethora of articles such as this one.

http://www.caranddriver.com/features...-lying-feature

 

I haven't done this because to be quite frank, it's not my job to evaluate every product this industry offers. The ONLY reason this test of the headers was even performed in the first place was because SDG sent his car here for custom tuning, with the headers as part of package. When I explained the results to him, he opted to remove them. End of story. I'm not going to sit here and test every possibly hardware combination of someone else's parts. If we're going to invest that kind of time, it will be for our own parts.

If I were you, I would not take them off until you can have your car put on a dyno and tested. Then, if you're willing, you can have them removed and tested again. That would be my recommendation. Again...as I've said a few times already, I'm only stating the results we saw here in our testing. I'm not making a universal statement about their product.

Correct. We did not see any benefit and in fact, observed the same slight losses in certain areas. This was exactly what we expected, as it mirrors the results we saw on the 997.2 Turbo. The headers only became beneficial once we added a larger turbocharger, which is why we're revisiting them now on our own 991 Turbo S.

And this is exactly what you should do. Shift points, drag racing, road racing...that's all sort of irrelevant because everyone has a different style of driving and a different way they use their car. Some people short-shift manually, some people rely on Sport or SportPlus, some people never hit the kick-down switch for overboost mode...so many variables. Whether or not the effects on performance from the headers will effect you or not is entirely up to you to decide. You seem like you might be a slightly analytical guy, so this is a good opportunity for you. I'm simply presenting a results (heck I didn't even want to present it, but SDG did) and allowing the readers to draw their own conclusions. I've been totally transparent about how we performed the tests and the ways we tried to adjust for the part. After that, it's up to everyone else to decide.

 

Unfortunately there are no awd dynos available to the public in Austin. I have tried to find one and cannot.

Only one question you have left to answer, what is the accuracy and margin of error in your dyno? I think you have a Dynojet right?

 

WRS, I completely feel your frustration as a consumer. It appears that your are wondering about the real value of the headers, why not just take them off, put the OEM ones on and get back to us with your impression after? I know there is cost for doing this, but this will give yourself peace of mind. And it's a price we pay in pursuit of our passion to have faster cars.
SDG did himself no favor by telling everyone about the result of his newly purchased headers. But he shared it with us to give us some data points to make informative decisions.
Just my 2 cents.

 

1.) Cost as you pointed out

2.) The data doesn't convince me that the power loss will matter if it even exists in my configuration.