Most HP made on factory bottom end?

[Mikie]

Ok guys,
We all know that once you go over 400 rwhp that the factory rods and pistons in the 4.6 is possibly on borrowed time.
Post up some of your high hp numbers and how long you have been going on your factory bottom end.
Im at 419 right now and want a few more. I have been told that with my safe tune on the car, I can get 460 or so and be ok.

Lets hear your numbers....

Edit* We are talking 2v only

 

[02nightmaregt]

460! Damn that would be kick a$$. Now im intrested too

 

[mrvax]

IMO, even a safe tune >400rwhp and you live on borrowed time. I knew of a turbocharged 4.6 on a stock bottom that was up to 450rwhp before it grenaded.

Just have either the $ or a forged block lying in wait. Good luck!

 

[navarro98gt]

My friend has been running 459rwhp 396rwt on his stock bottom for the last two years without a problem. He even runs it at the track quite frequently (11.58 @119.4mph)

 

[bhuff30]

The amount of power you can make safely really depends on the setup. For example, you can make more rwhp safely with a turbo than a blower because blowers draw their power from the crank. That means the power going through the rods and pistons is what you are making at the wheels plus the 40hp it takes to spin the blower. So if you are making 400 at the wheels, then the pistons and rods are seeing 440hp while the rods on the turbo setup would see a true 400. Their are of course other losses, but those are the same weather you are blown, sprayed or turbo'd, so we are ignornig them.

It also depends on peak cylinder pressure, and thus the peak loads on the crank. Obviously, detonation will do a lot of damage quickly. But also, if you run less timing and more boost, you can make more power safely. By doing this, you increase the average pressure in the cylinder during the combustion stroke, without increasing the peak pressure.

I'd argue that rpms have a major factor in connecting rod failures as well. The forces that rpms see from rpms are greater than what you'd see during a normal combustion event. It is much easier for a rod to resist compression than being pulled apart by rpms.

Considering all of these, I'd consider a stock block with a centrifigual blower that you are reving high to be more risky to make big power on. A turbo setup would be safer, and a roots blower would be somewhere in the middle.

 

[cobra killer]

This 2v has been running for 1 year with this setup.

487 rwhp / 431 lbft - stock block 2V on pump gas - MPH Forums

 

[justinschmidt1]

There was a thread like this on corral...Im pretty sure there was a guy over there makiing a bit over 500 rwhp for years.

 

[Tim2002GT]

PM hotmustang331. I think he had his stock bottom end GT over 500 whp before the accident.

 

[CobraRed_96_GT]

PM hotmustang331. I think he had his stock bottom end GT over 500 whp before the accident.

Yup, stock bottom end:

But his daily set-up i believe was 477/466

 

[SaleenGT2001]

my buddy has 60K on his KB setup

447/463 on 93 and he beats the crap out of it.

also has ran it on the race side of the chip with 110. not sure of the power but i'd guess over 475.(stock KB tunes) the car has had the blower since the first 100 miles it was driven from the dealer

 

[04GTMustang]

these 2vs can take a good bit of power. i sprayed 150 shot on mine for a while and a 200 shot a few times and now im on 11psi with my kb with the kb tune.

i know a guy making 440rwhp on his stock motor with a kb at 11psi he has a dyno tune though.

 

[justinschmidt1]

Whats with all the "400hp" limit stories then?


How many people have actually grenaded a 4.6 becuase of too much power?

 

[CobraRed_96_GT]

Whats with all the "400hp" limit stories then?


How many people have actually grenaded a 4.6 becuase of too much power?

First of all I've always seen it being the 420-430rwhp recommended ceiling. And this is an area that's in consideration of keeping the reliability of the car. Also - the limit isn't platform specific which makes it vary as well. A ported head with accommodating cam set-up making less psi but the same power is more suited for running reliably. Also a turbo set-up is less strain than a positive displacement set-up. Lot's of variables.

 

[02nightmaregt]

First of all I've always seen it being the 420-430rwhp recommended ceiling. And this is an area that's in consideration of keeping the reliability of the car. Also - the limit isn't platform specific which makes it vary as well. A ported head with accommodating cam set-up making less psi but the same power is more suited for running reliably. Also a turbo set-up is less strain than a positive displacement set-up. Lot's of variables.

Thats what i was thinking. Turbo doesnt shock the DT as bad. MMMMM Turbo stang

 

[Mustang92]

Whats with all the "400hp" limit stories then?


How many people have actually grenaded a 4.6 becuase of too much power?

Because of people from the late 90's to early 00's that grenaded their engines making 450-475RWHP on a stock bottom end. I've personally witnessed two cars a 99 GT and a 02 GT both put holes in the side of their block after a rod snapped it half. People like that did it and told others to keep the power below 450 and that info just gets passed on so people don't make the same mistakes they did.

Bill

 

[blubullett]

Its all in the tune...page 190 mmff aug 2007: 654 hp and 547 lb-ft, on an engine dyno.

 

[mklovell]

The common denominator is a good tune.

I have run 440rwhp (on the dyno) in drag tune which taking into consideration a 15% drive train loss puts the engine just over 500hp. This is a setup I have run going on 2 years now.

Still running stong even with drag strip runs running into the 6500rpm red line through the traps.

Keep the 93 octane in it, good fuel pressure and treat the engine respectfully as in keep it off the rev limiter when it's cold, or for that matter keep it off the limiter unless really necessary and you'll be fine.

It's really a matter of using it and not abusing it......

 

[the98stang]

It depends on the type of forced induction used (turbo, centrifugal, roots), what AFR you run & timing, previous engine condition, etc. There are too many variables to list. Some pop at 380 while some can take over 500. I have been running over 400whp for almost 3 years now (I'm most likely pushing 430-440 right now).

If you tune it for conservative AFR with moderate timing and your engine is healthy (compression) to begin with, 400-430 would be just fine. Especially with a turbo or centrifugal blower, as roots blowers cause more stress on the engine.

 

[PonyboyIsaac]

been at 388rwhp and 401rwtq for 2yrs. Had 378rwhp 392rwtq for a year before that.Not the highest power levels but still decent and she hasnt given up on me yet. I dont drive the car to much anymore,only about once or twice a week but when i do drive it, i do give it a good thrashing as shown on this vid. YouTube - Quick highway pull in Kenne bell Gt, some blower whine
I'm not abusive with it but i do get on it, and i havent had a problem yet. Had the car custom tuned, like already stated i think that is the key to surviving for a good while.

 

[hotmustang331]

Yep, as the above have said...I made a peak of 550RWHP. That was with the boost climbing until he (dyno operator) shut it down, because it was having trouble building boost due to the light load the dyno puts on the car.
I daily drove the car @ 9-10 PSI which was somewhere between 47X and 500...I really cant remember and it depended on the PSI. I think 10PSI was 499RWHP. I went WOT ALL THE TIME....I wasnt easy on it by any means.

That car gave me almost ZERO trouble....infact I have had more problems out of my 03 cobra making just 476RWHP and 29K miles than I did with my GT @ over 70,000 miles. It was turbo charged around 55K miles....before then was cammed since around 20K miles and seen an uncountable number of 6200-6400RPM shifts.

My cobra started missing the other day....and now tonight its breaking up @ WOT and the miss is pretty bad at idle. Its like one thing after another and I just hope its nothing serious. So far just alot of more or less minor problems.