4.4 to a 4.6is motor, oh what a thing.

[Plattus1000]

Originally Posted by crystalworks

On a 4.6L Mustang GT I gained quite a bit by going long tube equal length headers. I can't remember exactly how much as it was so long ago... but I remember it was over 30rwhp.

I would not be surprised to see gains... but if the S62 got 26hp, I'd be expecting 15-20hp out of the M62.

To be fair, the 26hp gain was OVER a Dinan headers/exhaust system. So over a stock s62, you could be looking at 50+hp just from bolting them on and with a good tune, even more.

Now on a stock 4.6, I'm thinking 40+hp after a good tune. 30 would be fine too but I expect better than that.

[crystalworks]

Originally Posted by Plattus1000

To be fair, the 26hp gain was OVER a Dinan headers/exhaust system. So over a stock s62, you could be looking at 50+hp just from bolting them on and with a good tune, even more.

Now on a stock 4.6, I'm thinking 40+hp after a good tune. 30 would be fine too but I expect better than that.

True, forgot that dyno was over Dinan.

At any rate, I am interested to see what such a ludicrously expensive (I understand the asking price, just could never personally justify it) set of headers does to the M62b46. With tune, I still think it will be closer to the 20-30whp range over stock. Still very interested though. I'd be excited if in your shoes.

[Plattus1000]

I'm about to burst with excitement. I'm so looking forward to getting rid of my cats and running free.

[bcredliner]

I think we should keep this discussion to X5 V8s. It is easy to make header results confusing as ranges of improvement vary by the product, vehicle and the existing HP/TQ at that point of installation.

I view before and after mods dyno tests as directional. The only definitive test to me to confirm I made the right choice of mod is how much less time it takes to get from point A to point B. How much I paid for each tenth of a second reduction in time from 0-60 mph. Torque gets you going and HP keeps you going. Torque is king. Look for packages where all components are matched to a tune with documented results. Otherwise it will be pure luck if you don't spend too much to get the results you want and be on that dreaded path of two steps forward one step back.

When you start doing other mods, especially those that allow or force more air into the engine, header benefits become a more important consideration but largely because of the cost per the tenth of a second improvement in 0--60 time for an X5 4.4, 4.6, 4.80, I don't think headers come near to making the short list of best mods. When you ask a tuner what mods to do, the response is always something like---how fast do you want to go. That's how to decide when headers fit the go fast budget.

[Plattus1000]

BCredliner - - - I agree to a point but as you know from our past, I go with my heart first with a bit of the cerebellum mixed in. I'm optimistic, more so than I think you are. Not for any reason other than optimism's sake.

It will be a neat test to be going on a stock 4.6. I wish it was also a stock exhaust to begin with to give a real test to the new headers/exhaust but I think it'll be great fun just to hear them fire up.

I'm a keen admirer of your butterfly cutoffs. Something tells me that in Seattle tunnels, that would be good fun.

[Plattus1000]

JUST ARRIVED!!!










I will to the best of my ability, try to have a before and after dyno posted before mif February. Done @ DUDMD's shop so he can tune the engine. That and, it's Dima.

I'll still get another dyno before all that on this tune so that question gets answered.

Jed made these for the s62 but they'll fit the holes for all these blocks so we'll get an idea what gains can be had on a non s62.

If by chance you've got a spare m5 steering box, m5 sway bar or anything else I should mod while in there, I'd be forever grateful. These last few months wiped me out. I think we'll drop the engine so it'll all come out. Good time to look for leaks and whatnot on this girl's heart. Perhaps a good time to attach those engine badges I had made up.

In any case, I think it will be great to see what Dima can pull out of these on my 4.6 because on the 4.9 s62 Jed got impressive numbers. 26hp over Dinan M5 headers doing the math, thats over 65hp over stock.

I might need a muffler. Any way I can cut and weld 2 small ones together at an angle to replace the resonator? Butterfly cutout... Yes. I hope, it all costs $ I guess.
On the headers:

If you were on the fence about purchasing a set, I know they're expensive and you'll probably wait till dyno numbers come in but this might just might be the thing to push you over the line.

Just look at what you get as extras!!!





There are decals too but I'll post pics of them on the car once applied.

On to that dyno. Yo Dima! I'm bring'n the heat.

[Plattus1000]

Update;
I ran on 2 different dyno's today to confirm but the results were, odd to say the least.

I've lost 20 hp since the tune and my afr is goofballed. I'll deal with that when Jed and I are done with the exhaust. My departure keeps getting pushed back by details but I'll leave this Saturday at the latest.








This one shows last year pre and today's post tune but the difference is about a year's time and not very impressive concidering the higher numbers were from a stock 4.4 DME tune.

[dannyzabolotny]

Man those are some crazy low numbers, what happened? A stock 4.4 puts down more power than that...

[Plattus1000]

Cam position sensor and an o2 sensor on bnk 2 keep coming up.

As to the numbers, each machine reads completely different and I don't remember the equation to get close to true rwhp but I don't think a stock 4.4 would run higher numbers on these machines.

DUDMD is the guy to explain all the info and how it gets processed, he totally has his dyno understood and can explain pretty much everything to a guy. (minus that 4th readout down. That was a freaky thing to see when it happened) That, a stock 4.4 would destroy.

We were all wondering what happened there but 5 minutes later things got better. Not terribly better but better. Still wondering why the AFR wanders all over the place and why the advance is so off.

I have my stock 4.4 dyno in here somewhere. (this thread)

[crystalworks]

For RWD I think there is a 10-15% drivetrain loss, but those numbers are still very low for a 4.6. Even at 20% loss it should be in the 260rwhp range. So something is amiss.