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  #21 (permalink)  
Old 07-25-2020, 05:30 PM
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  #22 (permalink)  
Old 07-25-2020, 05:41 PM
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  #23 (permalink)  
Old 07-25-2020, 11:24 PM
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Not trying to cause any friction here, but I am interested in the engine build. I understand some things may be proprietary. That is huge power and I would love to know more about it.

Again not trying to annoy you, but I would point out that to get an N/A engine to breath in more than twice the air that it displaces requires tuning to perfection the intake runners and ports and the exhaust ports and pipes. That is much easier to do on an engine dyno than it is to do with an engine installed in a car with intake that fits under the hood and exhaust that fits the car. This is especially true if power robbing side pipes are used. This engine sounds like it would be very interesting to run on an engine dyno and then on a chassis dyno after the install.

I personally find things like this extremely interesting. Call me an engine geek, if you will.

Also how peaky is the torque curve?
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Old 07-26-2020, 03:08 AM
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Lets give the OP the benefit of the doubt an assume he actually did buy two (!!) Roush Yates FR9 NASCAR engines. If we use the claimed 900 HP target which is in the ball park for an FR9 engine and accept the engine produces the power in the neighborhood of 7500 rpm then that only requires 630 ft/lbs of torque. There are many large displacement engines in cars on the site here, that produce that level of torque and more at decidedly lower engine speeds that do not seem to experience the mechanical failure the OP has experienced.

Even if he actually does use an FR9 engine, 639 ft/lbs torque is nothing particularly remarkable and certainly not adequate to do that level of damage out of the box so to speak. I am still of the opinion the car was abused, not maintained and eventually failed most likely because it was not maintained.

The OP's representation of 900 FWHP and 875 RWHP is a significantly different FWHP to RWHP loss than any replica owner on the site that has ever posted. The OP's claim to have measured his RWHP at 875 would imply a chassis dyno session and obviously documentation from the shop that did the pull. He could easily put the doubts to rest by producing a copy of that pull.

As olddog has already pointed out, the side pipes alone cost two bushel baskets of TQ and HP. Ignoring side pipes it is not uncommon to see powertrain losses approximating 15% if not more. That means the 630 ft/lb torque number would drop to a 530-ish number at the wheel in a best case scenario. My guess is likely lower. This brings us back to abusive operation and inadequate maintenance or perhaps no maintenance at all, as the culprit.

I am obviously still suspicious. To the OP, I am sure we all would like to see a picture of the engine in your car and some supporting dyno pulls to validate the RWHP differential you reported. Additionally the PM you sent me claiming a 208 MPH top speed for your Cobra seems, like a number of your other claims, a bit optimistic. If we ignore the fact that a 208 mph top speed would put you among the one or two fastest Cobra's ever (and likely the fastest in that elite group), I find it more than a little interesting that the mechanical failure did not happen at 208 mph !?!?!

Bottom line though, the failure comes back to minimally a maintenance issue and probably an abuse issue also. If it was the previous owner that abused the car then the pregnant question becomes, after putting an engine that is that powerful into the car why did you not do a thorough vehicle and in particular powertrain inspection before putting yourself and potentially others at risk and certainly before driving the car 208 mph.

As olddog observed and I think the OP had indicated, some of the damage may have predated his ownership of the car. Certainly he had to see the diff mounting issues when he installed the driveshaft and once again before driving the car 208 MPH — right?

I am still smelling a rat and it is not a Chevrolet ...


Ed
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Last edited by eschaider; 07-26-2020 at 04:40 AM.. Reason: Spelling & Grammar
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  #25 (permalink)  
Old 07-26-2020, 07:55 AM
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In general, the torque of a normally aspirated engine is directly related to and limited by its displacement, so a 358 ci engine has a maximum potential torque of about 450-500 ft lbs, depending upon multiple factors including compression ratio, dry sump?, etc.

Horsepower is a measure of work, is a calculated number based upon the torque an engine generates and its corresponding rpm, such that mathematically the numbers are always the same at 5252 rpms.

You can do the calculations, so for a 358 ci engine to make 900 hp , it would have to run likely higher than 9000 rpm’s , generating near maximum torque at that rpm.
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  #26 (permalink)  
Old 07-26-2020, 12:18 PM
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Conceptually you are spot on Tiony. Mathmatically you missed by a fat finger press probably.

Horsepower is torque per unit time divided by 5252, as you indicated. The formula is;

HP = (TQ * RPM)/5252

We can do a little algebraic reshuffle of the basic formula to solve for TQ instead of HP. To do that we need to first multiply both sides by 5252 to remove it from the right hand of the formula. When we do the formula becomes;

HP * 5252 = TQ * RPM

Now we can easily solve for TQ by dividing both sides BY RPM and we get;

(HP * 5252)/RPM = TQ

I suspect the FR9 engine hits peak power at 7000 to 7500 RPM with a max engine speed of 8500 maybe 9000 RPM — this is after all a purpose built racing engine.

If we use the 7500 RPPM number and plug in the original numbers he claimed (before changing his opening post) to the TQ solving version of the formula we get

(900 HP * 5252) / 7500 = 630 ft/lbs of TQ

Not all that much although still impressive, particularly for the engine displacement and the rpm it can deliver it at.



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  #27 (permalink)  
Old 07-26-2020, 05:18 PM
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Everything except the failure of the metal bracket. In the process, I also picked up the trolls on the blog. That's great. You guys are awesome. I appreciate the help. I'm out.

Last edited by Moto Guru; 07-27-2020 at 12:31 PM..
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Old 07-26-2020, 11:02 PM
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You come on here asking for help, yes.

People were honestly trying to give you help.

Then you started slandering a well known, well built, well liked manufacturer. Correct?

You really didn't base your claims against the manufacturer with indisputable facts.

Others pointed out that alternative possible reasons that may have been the root cause of the failure, which you dismissed outright and continued to blame the manufacturer.

Now on top of this the Hp claim, although not impossible, are suspicious. So it was questioned. Admittedly in the end, asking you to back up the claims with some proof.

Your response was to delete all your posts and call us trolls.

So you think that you can ask for help on your first post, make baseless, slanderous charges against a good manufacturer, ignore our thoughts, and we should all kiss your a$$ and help you without any question of all your questionable claims. If not, you will call us trolls and take your ball and go home. Well P H U C K that.

That all said, I would still like you to hang around and tell us more about the engine. Your still welcome.
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Old 07-26-2020, 11:33 PM
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According to Roush, the 358 Cup engine can make over 900 hp at 9300rpm, but the engine needs to idle at 2500 rpm.

Now is that a street engine?

No doubt, a fantastic engine, but completely useless in a street/occasional race car.
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Old 07-27-2020, 12:29 AM
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Originally Posted by Gaz64 View Post
According to Roush, the 358 Cup engine can make over 900 hp at 9300rpm, but the engine needs to idle at 2500 rpm.

Now is that a street engine?

No doubt, a fantastic engine, but completely useless in a street/occasional race car.

Thanks Gary, that adds additional texture to the investigation. If we use the Roush supplied data the engine torque is

(900 HP * 5252) / 9300 = 508 ft/lbs of TQ at the flywheel

If we use a conservative 15% powertrain loss, the Rear Wheel Torque comes out to 432 ft/lbs of torque — best case. This is essentially the middle of where most of us are, if not a bit below the middle for a typical Club Cobra enthusiast. Curiously none of us have experienced the OP's mechanical failure woes.

It is increasingly apparent the OP was a BS artist and like Rick (olddog) so eloquently put it, began slandering a well respected replica manufacturer without any evidence of the manufacturer causing or being the cause of the failure

I am more than ever convinced this guy or perhaps the previous owner abused the car, never maintained it and then the new owner (this guy) continued the abuse again without maintenance or even inspection prior to operation until mechanical failure occurred.

I seriously doubt there ever was a FR9 engine anywhere near the car. As Gary indicated, Roush's engine specs show the engine idling around 2500 rpm and as he so accurately pointed out this doesn't work well or otherwise for a non race car.

This was the OP's PM to me;

Quote:
Originally Posted by Moto Guru
NEXT TIME YOU WANT TO LOOK GOOD ON THE BLOG BY SHOOTING PEOPLE DOWN DO YOUR HOMEWORK.
YES I HAVE 900+HP
1/4 mile sub 10
Top speed 208.

https://roushyates.com/engines/ford-fr9-carb/
All his claims appear to have been fabricated. I find the 208 mph claim particularly interesting. I have never seen a 9 second drag car trap at 208 mph so that means the 208 mph has to be some sort of closed circuit performance. If I am not mistaken 208 mph in a Superformance Cobra is either the fastest or second fastest Cobra in the world.

I doubt this performance ever occurred. With a rear diff mount so badly damaged there is no way that car could even come near that sort of performance. I doubt he could get much past 100 mph, if that fast, without mechanical failure and serious on track vehicle control issues.

I call BS on all his posted facts and claims. I also seriously doubt he has even one, let alone two FR9 engines.

You and Gary were kind, Rick.


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Last edited by eschaider; 07-27-2020 at 12:51 AM.. Reason: Spelling & Grammar
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  #31 (permalink)  
Old 07-27-2020, 01:33 AM
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Roush Yates 358-cube NASCAR Sprint Cup Engine
RPM HP TQ
6,100 596.4 522.0
6,200 613.4 528.1
6,300 631.1 534.6
6,400 646.2 538.7
6,500 658.9 540.7
6,600 668.9 540.5
6,700 680.1 541.2
6,800 691.1 541.7
6,900 703.8 543.6
7,000 715.9 544.9
7,100 728.3 548.2
7,200 753.4 549.5
7,300 766.9 551.7
7,400 778.7 552.7
7,500 786.7 550.9
7,600 795.2 549.5
7,700 802.9 547.6
7,800 811.3 546.2
7,900 818.3 544.0
8,000 823.3 540.5
8,100 828.8 537.3
8,200 833.5 533.8
8,300 837.5 529.9
8,400 843.1 527.1
8,500 847.9 523.9
8,600 850.9 519.7
8,700 852.1 514.4
8,800 853.6 509.4
8,900 853.8 503.8
9,000 850.2 496.1
9,100 847.0 488.8
9,200 844.6 482.2

My numbers were a bit out,
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Old 07-27-2020, 01:39 AM
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I thought I remembered an 850-ish number but that was a couple of years ago Gary, so I gave the OP the benefit of the doubt and used his now obviously inflated numbers.

Stunningly good Sherlock Holmes work!.


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Old 07-27-2020, 03:01 AM
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Quote:
Originally Posted by eschaider View Post
I thought I remembered an 850-ish number but that was a couple of years ago Gary, so I gave the OP the benefit of the doubt and used his now obviously inflated numbers.

Stunningly good Sherlock Holmes work!.


Ed
The Cup engine is not quite as much as the OPs FR9 engine which is quoted by Roush at 900hp. I could only lay my hands on the Cup engine dyno data, to show a typical 358 torque/horsepower curve.

So I won't take Sherlock status on this one.

Gary
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Old 07-27-2020, 10:44 AM
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Well we said our piece. I think Elvis left the building, and I doubt he will return. No point in beating on a dead horse.

It's a shame, especially in these trying times of the plague.

Again the OP is still welcome.

Just understand when you jump to unsubstantiated assumptions, someone will point it out. We are not here to slander the manufacturers that makes this club possible. If a manufacturer does indeed deserve a bad reputation, we will call it out, but one unsubstantiated claim doesn't meet that threshold, in my opinion.

Opinions expressed here are only the opinions of this poster and do not speak for this site or anyone else.

Last edited by olddog; 07-27-2020 at 10:56 AM..
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Old 07-27-2020, 11:09 AM
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Quote:
Originally Posted by olddog View Post
You come on here asking for help, yes.

People were honestly trying to give you help.

Then you started slandering a well known, well built, well liked manufacturer. Correct?

You really didn't base your claims against the manufacturer with indisputable facts.

Others pointed out that alternative possible reasons that may have been the root cause of the failure, which you dismissed outright and continued to blame the manufacturer.

Now on top of this the Hp claim, although not impossible, are suspicious. So it was questioned. Admittedly in the end, asking you to back up the claims with some proof.

Your response was to delete all your posts and call us trolls.

So you think that you can ask for help on your first post, make baseless, slanderous charges against a good manufacturer, ignore our thoughts, and we should all kiss your a$$ and help you without any question of all your questionable claims. If not, you will call us trolls and take your ball and go home. Well P H U C K that.

That all said, I would still like you to hang around and tell us more about the engine. Your still welcome.
Add to that not willing to accept any responsibility that the root cause is his engine. Yeah, I think he had the role of troll reversed.
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Old 07-27-2020, 11:16 AM
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Originally Posted by olddog View Post
Well we said our piece. I think Elvis left the building, and I doubt he will return. No point in beating on a dead horse.

It's a shame, especially in these trying times of the plague.

Again the OP is still welcome.

Just understand when you jump to unsubstantiated assumptions, someone will point it out. We are not here to slander the manufacturers that makes this club possible. If a manufacturer does indeed deserve a bad reputation, we will call it out, but one unsubstantiated claim doesn't meet that threshold, in my opinion.

Opinions expressed here are only the opinions of this poster and do not speak for this site or anyone else.
Add that: Be Truthful. Don't exaggerate. With the collective centuries of experience and knowledge, it's practically impossible to pull the wool over our eyes.
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Old 07-27-2020, 12:47 PM
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By the way, Took out the entire bracket today. It crumbles if you bend it by hand. No-one every did anything to it, no modifications no tinkering anything at all there. Paint weld everything original.
1. SP F*cked up on that weld and metal choice. (weld is not continuous, spot welded only). Don't get me wrong nothing else wrong with it, still keeping it (car). But it's a f-up there in the manufacturing.
2. Metal is somehow crystallized, breaks easily. hand strength (not back and forward, single bend break).
3. Bracket was manufactured with 3 pieces of steel, with their 45 degree angles, but only 2 spot welds on one of 45 degree sides.
4. tested driver side (solid) no issues. Welded continuously, good and Not crystallized in any way. alloy is good/solid. (still going to re-enforce it from below).

thank you.
Have a great day.
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Old 07-27-2020, 02:40 PM
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And how did you go 208 mph in that car ...


ed
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Old 07-27-2020, 07:05 PM
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Quote:
Originally Posted by Moto Guru View Post
By the way, Took out the entire bracket today. It crumbles if you bend it by hand. No-one every did anything to it, no modifications no tinkering anything at all there. Paint weld everything original.
1. SP F*cked up on that weld and metal choice. (weld is not continuous, spot welded only). Don't get me wrong nothing else wrong with it, still keeping it (car). But it's a f-up there in the manufacturing.
2. Metal is somehow crystallized, breaks easily. hand strength (not back and forward, single bend break).
3. Bracket was manufactured with 3 pieces of steel, with their 45 degree angles, but only 2 spot welds on one of 45 degree sides.
4. tested driver side (solid) no issues. Welded continuously, good and Not crystallized in any way. alloy is good/solid. (still going to re-enforce it from below).

thank you.
Have a great day.
Contact a dealer or take samples of the metal to them and have them look into this. If the metal is crystallized, I believe heat had to be involved. It could have been when the metal tube for the frame was made (before being sold to SPF), or when welded, or after the sale. It is possible it was caused by flexing around half broken (metal fatigue). In any event, SPF should be made aware. If they bought a bad batch of tubing they would want to know. Perhaps they employed someone for a short period of time and that person also worked on a few other cars.

You truly believe it was a manufacturers issue, so do the right thing and inform them. You could save someones life, or cost someone their life by not reporting this, if you are correct.

My mind was on the frame, but you were talking about the bracket. Everything still applies, but it is the bracket not the frame.
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Last edited by olddog; 07-27-2020 at 07:11 PM.. Reason: Correction
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