5.8 Bottom End

[COME CORRECT]

I have two questions:

What is 5.8/GT 500 bottom end rated at horse power wise at the crank.

How much horsepower would that be at the at rear wheels.

We are changing to custom grind cams and springs..

Thanks you in advance.

Charles...

 

[1 Alibi 2]

The 13/14 GT500 5.8L engine was factory rated @ 662 hp / 631 tq.
My stock 2014 put 585 to the tires.

 

[Dusten]

I think he means what can they handle.

Depends, how many rpm do you want to spin

 

[raustin0017]

Many, many 13/14 owners are getting over 700 to the rear on stock internals.
There is a limit and some have found it with critical failures.

 

[Jam421]

There are a bunch of guys who'd know way more about max power for the 5.8. I've been told around 850HP? But very much likely depends more on how high you spin it, fuel and tune. Guys have popped motors in the torque band peak range not even up top with less than 800HP. There are also guys here on the forum making WAY more than 850HP on stock internals.
Chassis dyno shops in our area with dynonometers typically estimate 15% drivetrain loss. So..on that estimate 680RWHP would = 800 crank. Mustang Dynos give lower rw #'s. Once I did a tune eval pull at 2 shops one month apart. Temps were about the same. Can't comment on air quality. What pulled 658rw on a Mustang Dyno pulled 716rw on a Dynonometer. Gears also have some effect on dyno numbers. You could also do 2 pulls...one week apart on the same dyno and #'s change. Tuners might better explain the parameters responsible for that.

 

[2011 gtcs]

High RPMs and aggressive timing with bad fuel is what kills the bottom end on the 5.8, I made over 800whp on my 13 GT500 with a 3.6KB and it's still living to this day with the new owner. My current 14 GT500 is over 700whp and is running great. If you want to go over 700+whp either run E85 or run good fuel, I personally run MS100 full time, and dont shift higher than 6k.

 

[COME CORRECT]

Thanks. Looking into rods and pistons just to be safe. Making 650 now on a superflow dyno and I've upgraded the fuel system going to a 3.4 Whipple.

 

[2011 gtcs]

Thanks. Looking into rods and pistons just to be safe. Making 650 now on a superflow dyno and I've upgraded the fuel system going to a 3.4 Whipple.

Give JDM engineering a call for rods and pistons

 

[biminiLX]

That 3.4 Whipple could make 1000rwhp and it could make 750rwhp.
Depends on boost, rpm, timing, fuel.
What are your goals?
Do you ever take it to the track?
I usually think 750-800rwhp is reasonable if you respect rpm and octane.
You don't necessarily have to jump to a built bottom end, but you will in order to maximize it--again all going back to your goals.
-J

 

[boduke0220]

93 octane is your enemy over 700rwhp..in my opinion. I see it on the Coyotes and 5.8's too when people try to push big power on pump and end up doing a Piston delete. Just go E85 or a 100 octane tune and I think 800 to the wheels would last a long time if properly taken care of. Wish my car had been

 

[COME CORRECT]

Thanks everyone. I ordered my 2013 GT 500 in 2012 and drove it through one winter, then maybe 3 to 6 months a year. Since then and it had become pretty much a show car. My suspension is on point and my intent here is to aggressively track this car at Hot Rod Magazines 1/4 mile event and have done a 1/2 event. I run 98/100/105 (octane) Sunoco unleaded most of the time. I have a tune for 93 and only cruse with that. I plan to drive down Florida and Georgia to knock a few heads...