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...

OK, had another look, this is as you say without headers and also with a full CAI Perrin intake, so not very representative for this case in any sense, really.

I have the P&L EL catted header. I drove it around for about a week before getting the Ecutek tune and could definitely feel an increase across the power band. I felt I lost a tiny bit down low at like 2500RPM but stronger elsewhere.

However, once I got the tune specific for the header it made a huge difference. I definitely wouldn't just buy a header and not get a tune. Dollar for dollar you are probably better off initially investing in the tuning device and tune instead of the header.

I already ordered my FT86 headers, so I shall post dynos once I get it.... wghich should be in about 2 months :cry:

Yep it will be a wait. OK by me, it will probably get a bit better by then.

To repeat myself. I want an improved subjective feel and preferably without a tune. A proper 3rd party tune will cost me more than headers and I actually prefer amending the root cause (header design) rather than (incompletely) patching things up with a remap. A remap also opens up way to many variables I can obsess over and thus destroys the fun of driving the car for me and I'll end up buying something else completely stock. BTDT, know thyself.

So no more "do a remap" please.

I totally feel your frustration...it seems lately, that every and any thread on the engine topic boards seem to get derailed, bombarded and become off-topic very quickly with replies and suggestions of Tuning, to help band aid things.

It makes reading engine threads annoying and un-enjoyable anymore.

People need to stay on topic and focus on the posted part in discussion...instead of jumping the reply-gun, and suggesting or blaming faulty tuning all the time.

@trettios: i'm with you on this. I want to improve the responsiveness without going crazy with engine and tons of driveline mods. That's why my first mod will be lightweight wheels and summer tires. 17x8 with sticky 215's or 225's anymore and it's a reduction in performance. After that, I'll probably be swapping in whileline diff bushing inserts, because the lash is driving me crazy. Once all that is done, if I'm not happy I'll revisit headers, and if the Ft86sf catted header works well (AFR wise) without a tune, I'll probably get it.

Yep fooddude and PMPB, that is my philosophy, moderate improvements, it's very easy to get carried away...

Shipping sorted and ordered! Thanks all for the help.

What did you end up buying?

The Speedfactory UEL catted header. Now just need to play cool in the waiting game...

Am I the only person that thinks that dyno is complete BS? This header has nothing different in it compared to a lot of the ones out there. I would like to see some third party dynos to see if the magical unicorn header that eliminates the dip with no tune really holds up to that chart.

It has been confirmed on one customer car, and butt dyno by all customers that received theirs...
It was just a matter of time till some found the right config, we knew that header design can change the dip...

So in the past two years of tuning this car, one header out of the 10-12 out there eliminates the dip without a tune?

I'm sorry, but I need real proof and not vendor bloated dynos. We'll let the third party dynos do the talking. If there's no dip in the 5-10 people that dyno on it with a stock tune, then I will keep my mouth shut and I bought the wrong header. I'm just saying I think you will be quite surprised about the outcome.

It may attack it a little bit as Rev Works showed that as well with theirs on its own, but to completely eliminate it.... nope.

We'll see in a few months time, for me, or sooner on here.

Till then, I choose to trust the guys at FT86Speedfactory, I have found their product reviews reliable and their dyno was on a stock car. I don't see why they would draw the lines themselves when they know for a fact that would backfire on them big time within months.

And one in 10 sounds like a good statistic. That is about the same chance that one out of ten beginners would not hit a false tune on a violin. If that is prowess or just chance is another question. ;)

It all depends how much R&D time the shop was willing to put into a design. Some places may have had goals they wanted to hit, and when they got there they stopped instead of probing to just see how far they could go.

There's a ton of things that affect how much (and where in the rev range) a header will make more power, and it's all a balance against their goals, and R&D cost.

Just because some vendor was happy with their results doesn't mean someone else won't get better results with more R&D.

I understand you being skeptical and wanting to see 3rd party numbers. I totally agree even though i jumped and bought the FT86SF catted header already. (havent installed it yet though). There is only one problem that i see with your logic. the Borla UEL actually does a decent job of filling the torque dip as well. Look to the Drift Office: UEL Shoot out. http://www.ft86club.com/forums/showthread.php?t=60586

Again i dont blame you for being skeptical as i usually am too but dont go out calling vendors liars right off the bat before you have proof they are full of shit.

There is nothing wrong with being skeptical of a single broken dyno chart (notice the gap in the lines for their header) and claims of being able to completely eliminate the dip without a tune. Those kinds of claims reek of snake oil until actual customers start posting up dyno charts backing it up.

How about you go install your header and get it dyno'd? I don't think the Drift Office shootout was without tuning. They said 'same tuning methodology'. That implies they tuned for each header to get the best possible results with the same fuel.

I'd be amazed if a header alone magically eliminated the dip without any tuning whatsoever. I'd also like to see shops follow a standard instead of some using 4th gear pulls, then the E85 guys comparing 5th gear E85 pulls to 4th gear pump gas...

Again I did say a couple times i dont blame you for being skeptical. Never said you were wrong for being skeptical.

I do plan to get to a dyno as soon as i can after i get mine installed. I haven't the time or money to get a stock base line and a fallow up dyno so the dyno will be done with a CBE, Nameless Combo pipe with cat and res plus the FT86SF catted header. It has been noted through out the forum that a CBE and OP/FP does not fix the dip so the added parts shouldnt skew things too much.

I stand corrected on the Drift office dyno chart. you were right, after doing more digging the dyno on their main page was with tuning.

Just some fyi the main reason i bought this header is because i wanted a header that was catted. Mainly for volume (or the lack of) and while still illegal in Cali i have a better chance of passing emissions with a cat than without.

I do agree that it would be nice if shops would all fallow the same guidelines when dynoing cars. it would make it much easier to compare apples to apples.

I have no problem believing it, there is no reason why there *should* be a torque dip in the first place if exhaust gas pulses are blending evenly across the revrange. The Speedfactory header also cuts some torque peaks before and after the dip so it might be a matter of blending the pulses just a bit instead of attempting to completely avoid interference.

And as pointed out above, with a remap, the whole torque curve even moves up and even peaks on some headers, is that impossible too? That was a rhetoric of course and remaps aren't the subject of this thread...

On the stock map, compared to other good headers we're talking 5hp here or there at the most, so no need getting too worked up about it, really.

You have no idea what you are talking about.

These effects have been explained, and the science behind it is why people are skeptical about the claims here.

Sounds a bit harsh, but ok. Then please point me to the science, not a frequent visitor here. Thank you.

Edit: know what. I do feel a bit offended. You have no idea who I am and on what level I choose to put my explanation. I'm not sure I want to hang around if this is representative of the general tone on this forum.