E85 On Stock 2017+ Cars Specifically
 

Hey guys. After only two and a half years of ownership, I suddenly got the urge to make some power gains. Not that the car needed it, but I was stupid and read a bunch of posts in the tuning section and it got me excited.

So of course the best way to go is to get aftermarket headers and then tune for E85 for max power. But from reading the forum a bit, it appears that the 2017+ headers are better flowing from the factory compared to the previous MY's.

In this case, can I just stick to stock headers and not worry about having to go aftermarket? (I understand that you can run e85 with stock headers) The reason I'm questioning this is because even if I were to go aftermarket, my choice would be an equal length catted header anyway, so not too sure if it would be substantially different from stock headers.

It would be great to hear from 2017+ owners (or any MY) if they can give some experience and feedback whether stock car + E85 is worth the money for a tune, ie. if it helped with torque dip a lot or better overall torque. :thanks:

I would pick up open flash tablet and give it a try. 500 bucks new. E85 tune will get you to max na power levels. After that you can add a header to fill in the midrange a little.

I have a 2017 and I'm gonna be honest... I went e85 first then header and noticed next to nothing in terms of gains from the header. Still worth it for the sound though. Rumble rumble rumble

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Most of the gains of cheap headers is with the removal of the precat, so I doubt the larger/better MY17 headers are equivalent. An expensive Ace 4-2-1 header will be better still.


To run E85 you will need injectors, flex fuel sensor/kit, ECUtek or some tuning software, a tune, and if you want to be proactive/safe, even if it is probably not necessary, upgrade the fuel pump. If you go ECUtek then you need the key, their obd2 dongle, a license and then the tune, which all in is around a grand, so you can expect to pay $2-2.5k for everything then if you want to add a header then add $500-1500.

I'm assuming you got a new tune after the header, right?

The 2017+ have 5hp more from intake manifold, header, and new tune. So I doubt the new header is making more then 3 extra hp alone. Just look at before/after dynos of headers and subtract 3hp from the difference. Basically instead of 10hp you’ll get 7hp.
E85 is good choice. Flex fuel is highly recommended to both maximize the gains and minimize the risks.
You’ll want a custom tune for header + E85 to really get everything out of it.

The cats in the car really strangle the performance.

If you don't require cats, because race car, your fine, but it you do then even high flow cats restrict the flow.

This is where it gets tricky, the cat after all needs to function, there is more to it, but cell count is the main shopping point, 100 cell cats are all well and good, until a emmisions test is done, Euro 5 standards to be precise.

This is where you need a real cats and/or tuning and maybe fuel.

I've seen people who have been done for emmisions and sent for testing, they replaced their decat or punched out cats with aftermarket cats proir to the test, and failed the test.

If you can remove your restrictions there is some good power to be had.

In all honesty I recommend that you talk to your tuner, hopefully he has the knowledge and experience to point you in the right direction and if required, pass a emissions test.

There are no specific tunes for headers with e85 using OFT.

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As for the 17+ header, the primaries and secondaries are much larger than the pre 17 headers, they are actually larger than some of the aftermarket headers, the cat is the issue.

Whilst not as efficient as a ACE header, the OEM sans the cat flows extremely well.

For tuning I would look at Ecutek and find a good tuner (easier said than done), the added features and experience will pay off remarkably if you are trying to squeeze as much power as you can out of it.

I wish I had easy access to E85.

I’m not really familiar with OFT, sorry, so how are adjustments made? You can’t install headers and not do a tune and expect gains, so does the user make adjustments on their own?

N/A on e85 you don't need injectors or fuel pump at all. There's TONS of capacity in the fuel system. If it's boosted on e85, then it'll need injectors (and pump for safety).




I think they were saying there isn't canned/OTS tunes for it for e85/headers. A tuner can still custom tune it. Same basic process as EcuTek, just different tools.

Fuel pump is $189 for a DW300c and the DW700cc injectors are like $329, so subtract $500ish from my quote, but good to know. I’m boosted on E85 and always though E85 required a fuel upgrade, regardless. My mistake.

That is what I am saying, did he get a tune? Any significant change from the intake to the cats needs a tune or there can be losses. There are YouTube channels where they tested a CAI, headers, etc and found sometimes less power was achieved when a tune wasn’t used. He said headers made no difference, so I’m trying to understand how that could be.

Once you close in on 200 whp gains from additional components are minimal

Once you have reached 200whp, the next step is weight reduction. For NA purposes.