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Ford Voodoo V8 and why it is exotic
Posted: Mon Sep 19, 2016 6:20 pm
by kevm14
Exotic in this way, though:
I've seen a different type of problem with a GT350 track pack right in front of me, at VIR. Blew heavy smoke from the engine compartment area, owner said it was the oil filter slightly unscrewing itself due to engine vibrations at high RPM.
Yah the oil filter loosening up has been an issue. A lot of dealers aren't torquing them correctly (yup, it needs to be torqued to 18lbs).
Also, some that are torqued correctly have been still loosening up after a few thousand miles. The Voodoo has a lot of vibrations. There are new threads on the Mustang forums about wiring a safety harness/strap to the filter.
Nasty, nasty vibes. I don't trust these in the long run. I could be wrong.
But, I'll take the LS even though it is less interesting.
Re: Ford Voodoo V8 and why it is exotic
Posted: Mon Sep 19, 2016 6:27 pm
by kevm14
having owned an E30 M3 with an S14... if these V8 Mustangs revving to 8K are having issues with vibration right now this early.. just wait til accessory brackets for alternators and a/c start breaking and transmission and motor mounts begin failing... buzzy shift knob etc..
This is from a BMW forum BTW.
Re: Ford Voodoo V8 and why it is exotic
Posted: Tue Jan 30, 2018 10:13 am
by kevm14
Interesting discussion on the Voodoo.
https://www.ferrarichat.com/forum/threa ... 269/page-2
As recounted to me by a ford engineer the motor though, while putting out the power is a bit of a sales gimick. A flat plane crank of this size had never been done before simply because mo one saw how to solve the Vibration. Fords solution is massive counterweights on the crank, which negates the benefit of the low rotational mass inherant in a flat plane crank.
One could argue which sounds better a V12 or a bent V8, but the flat plane does not match up to either(maybe the ferrai flat plane has a unique sound at high revs). You can also see that ford sells an aftermarket Voodo block V8 with a traditional bent crank that has the same Hp and Ill bet like many a bent crank V8 it sounds sweet and is a smooth rever.
I also hear that the Cf wheels reduced the nurbering lap time by 10 secs alone which is a fantastic step forwards, their low weight/rotational mass probably has a big effect on accleration and braking too. .
So nothing against the Gt350R, of the current crop of cars it has to be in the top 5 and that includes exotics, its just that the flat plane crank in the motor is more of a sales usp than any real benefit. We'll see if or when the camaro looses a few hundred punds of lard and gets a real track motor how it measures up.
My guess is the z28 has to beat the Gt350R as a track machine. Fords followup will be the Gt500 which will be a turboed voodo block with bent crank somewhere north of 800hp. Maybe not an ideal track machine then but pretty unbeatable. Given all the lowly 400hp mustangs loosing control coming out of cars and coffe one wonders where it will all end.
maybe this Hp war will be put to bed by the insurance industrry as it was in the 60's. Given what we know about the rewriting of the EPA emisions and fuel economy regs from a technical standpoint I think 1000 hp is not too far off.
Still as we know 500hp and 3000lbs for a trackable car is infinitely preferable to a 3700lbs car regardelss of the Hp the heavier car may have. So hopefully we will see some lightweight specials too.
Notice the part about Ford selling a crate Voodoo with a regular split crank, and the twin turbo Voodoo in the GT500 is also a split plane. Their flat plane crank is really just a marketing exercise, with a lot of compromises. And apparently no future. Plus they just upped the output on the Coyote anyway.
Re: Ford Voodoo V8 and why it is exotic
Posted: Tue Jan 30, 2018 10:15 am
by kevm14
Not Voodoo related but the weight discussion was interesting.
problem with weight loss is customers want the comfort, convenience, status, luxury with their performance even on cars they take to the track
how many cars that have opt out a/c and stereo are actually delivered that way? i would say next to none. people want sound deadening, good stereos, etc. hard to sell a $100k plus stripper even to track drivers.
how many track drivers can actually tell if their 500+ hp car weighs 3500 or 3300 lbs? i bet very few but everyone can tell if it has a/c
Yes!!
You are exactly right. Specs and gadgets sell and so do "more" of things that most people can't understand.
500 of something is better than 400. 4 cams are better than 1, more buttons in the cockpit are better than none, etc.
The Viper ACR and some of these extreme track models are perfect for us but they don't sell. It is sad...
So when the Hellcat has 707hp, everyone talks about it. When the new ZL1 is the same speed, no one talks about it because it has "only" 650 hp.
No one quotes hp/lb. Everyone quotes horsepower. That is why I quote trap speed because it is the result of all of the fluff. I also like it because it is not traction dependent. 0-60, for example, depends greatly on a LARGE number of variables including:
- Tires
- Rear suspension setup
- Transmission (manual vs auto)
- The surface used
- THE DRIVER
Of those I'd say the biggest influence of trap speed is the transmission, due to shift times mainly. In the past, the extra losses of the auto were a big detriment to performance. Not today.
Re: Ford Voodoo V8 and why it is exotic
Posted: Tue Jan 30, 2018 10:18 am
by kevm14
These guys are surprisingly pragmatic. They actually race cars on tracks.
Yes, OHC *could* produce more power and more revs but it will *have* to in order to offset its significant disadvantages. The car will have to lose weight from everywhere. We'll have to see carbon bodywork, lighter glass, totally different suspension tuning. New shock valving, different springs, etc. Trans ratios would likely have to be shorter and using a higher numerical final drive so that any potential loss in low rev torque wouldn't be noticeable. Then, after having done that, the MPG would likely decrease.
All of that so you can see an extra 1k redline?
From an engineering sense, the updated Coyote *has* to rev to 7400 to keep up with the larger LT1. You can spin it as a desirable thing but that is the mechanical engineering reality. The other mechanical engineering reality is that the 6.2L LT1 is pretty maxxed out N/A. It either needs more displacement, more RPM or forced induction. They already did F/I with the LT4 and now LT5. They are looking at more RPM with the LT6 or LT7 whatever. And more displacement was done with the LS7 and I don't see that coming back. So I see DOHC in the near future for GM V8s.
Re: Ford Voodoo V8 and why it is exotic
Posted: Tue Jan 30, 2018 10:24 am
by kevm14
Man I should register.
Except that displacement doesn't really correlate to performance. Engine size, weight, mpg and CG is what really matters. Is it efficient in relation to how much fuel it consumes? Is it efficient based on what the engine actually weighs? Is the weight down low? Or is it up high?
Weight is precious...it must stay at a minimum.
Fuel is precious...must use less when possible.
Displacement is not precious.
It's a convenient number that most associate with efficiency. That correlation is questionable at best. Why should we care if our 550bhp, 400 lb engine that gets 25mpg is 1.1 liter or 8.1 liter?
We should care about which engine is larger in physical size, heavier or more thirsty. The HP/Liter ratio doesn't measure any of this.
And, I agree with you 100% on your point that most buyers don't look at or care about weight. OHC is there because it sells and most manufacturers know that "more" of everything sounds cooler on the website. Also, it would be expensive and embarrassing to switch engine architecture.
Thankfully, this site is not most buyers and we can have a good technical discussion that most buyers will not have.
And, like most of you, I hope the manual trans is always available in performance cars.
This guy is preaching!
Re: Ford Voodoo V8 and why it is exotic
Posted: Wed Jan 31, 2018 7:14 am
by Bob
I can personally confirm the visible tailpipe emissions from the GT350. I followed one up a windy road in California in my rental 430i. There was smoke every time he let off as he was hammering on it.
Re: Ford Voodoo V8 and why it is exotic
Posted: Wed Jan 31, 2018 8:07 am
by kevm14
Physics doesn't want that engine to exist.