Reducing the dip: Header without remap question
 

So, I'm happy with stock power levels* for my driving, but dislike the torque dip. Also dislike the idea of fiddling with a remap, the cost (time and money) of doing it properly is not something I want to do - BTDT.
There are some bolt-on catted headers that without a remap reduce the torque dip. Saw graphs of HKS and P&L (w/o cat), and FA20club and Nameless amongst other long tube headers probably do the same. My question: does anybody have experience with running these headers without a remap? Does it change the character of the engine to such an extent that the torque dip is no longer bothersome? This is purely subjective and that's the part I care about.

In short, if one does not want max. whp or a remap, but just wants a nicer character of the engine, is changing to a long pipe or 4-2-1 header alone a viable strategy or is the difference so little one might as well not bother without considering a remap?

PS: I want to keep the cat for emission and noise reasons, so decatting the stock header is not an option for me.

*have a aftermarket replacement filter (cosworth) and a resonated secondary catback.(Milltek) Works fine.

Stock..no dip...NO tune...nuff said ;)
http://www.ft86club.com/forums/showp...13&postcount=1

FWIW - you can get rid of the torque dip with just a remap for less than some headers.

With the OFT and a stage 1 ROM, the stock engine feels much smoother through the dip.

Wow, thanks!

No EL option that does the same? But UEL ain't bad ;)

+1*1,000,000

But is a header without a tune safe? How does it affect A/F ratio. Most of the time, less backpressure means the engine will be running a bit leaner, with our crap north american fuel and 12.5:1 compression ratio, I don't feel like I want to let this car run lean.

At the same time, more power, without messing around with the ECU is very appealing, especially when it comes to possible warranty work.

Well if your intake is stock, you won't be tricking the ecu in its MAF readings as such, so I can only assume that the makers of this car wanted it to deliver the extra power if the hardware was there?? The ECU has the AFR, load and amount of fuel injected in its programming, not?

No different than trusting generic remaps run on many many different real world configurations. Or no, make that, better to trust the OE mapping!?!

Just my perceptions , not an ECU guru or anything like that.

Seems exhaust mods tend to run rich, intake a bit lean. If I get this, I could log some AFR's on my set-up which is very conservative (see OP).
The more hardware mods, the bigger the need for a properly adjusted remap...

Glad you got some info matey, now go get it and enjoy dip free driving :)

Waiting for a reply from the vendor, but hej, it's sunday ;)

Don't count on it. This has been brought up multiple times. If I get headers I will be getting a tune as well.

Here's the only response to AFR on the ft86SF catted headers that I ever saw. This was the AFR before he installed headers though, I believe. So not sure it helps. Ft86SF has stated that the AFR sensor when they dynoed was broken so they have no numbers:
http://www.ft86club.com/forums/showp...postcount=1412

My experience is the opposite, I installed a 3" front pipe and my Fuel Economy went through the roof (did 31MPG once hammering the car through hills at 90MPH)

Added a KN drop in and fuel economy went down the shitter.... still my car runs leaner than it did from the factory with front pipe, catback and drop in filter.

I know they won't answer that Q as it's hard to answer depending on set-up and individual cars. I'm waiting for a reply for shipping alternatives so I can throw my money at them ;)

The AFR are a bit a gamble, but I intend to keep my stock overpipe and front pipe that should keep exhaust flow within reason even with better headers. And the better panel filter should lean up things again. I mean, it's almost a miracle that flat torque curve without a tune so in my perhaps naive hope is that these perfectly matched headers won't upset too much when keeping other mods minimal...

Haha. All of us perhaps should better say nothing and just wait until a customer measures the AFRs without a tune and this or similar set-up...