2014 Shelby GT500 - Connecting rods

[Fastback14]

I'm sure this question has probably been asked thousands of times on there, so if the mods want to delete thread, please do so.

So i'm getting to the point where I want to start modding my 14' Shelby. I planned on doing Boltons (Exhaust, Intake (TB included), Pulley, tune) and keeping it on 91 octane. My original goal was to make some where in the range of 680-730whp and be able to hopefully trap between 158-162mph in the half mile (bone stock I did 148mph). But again, with 91 octane (possibly e85 in the future) i'm not sure if these is achievable.

After doing a little more research on here and various other locations, I see that the connecting rods seem to be the weak point on these motors (5.8L).

I understand that every car is different and that it comes down to how the car is driven and the tune that's put on it. But, I wanted to see if there was a consensus on what a "safe" power level would be for these stock connecting rods on the Trinity motor (poll added).

From what I've seen, 650-700rwhp seems to be the "safe" limit for these stock connecting rods.

Thanks again guys for your input.

 

[biminiLX]

1/2 mile and standing mile are very difficult due to sustained load but as long as you run good octane and don’t over rev (hardest on rods) I’d build it for 750rwhp and not worry. Now anything can happen and you’ll want to make sure you have a great tuner and datalog but id say go for it.
Id really like to try the Indiana 1/2 mile this year
Good luck
-J

 

[Turbo98GT]

I'm sure this question has probably been asked thousands of times on there, so if the mods want to delete thread, please do so.

So i'm getting to the point where I want to start modding my 14' Shelby. I planned on doing Boltons (Exhaust, Intake (TB included), Pulley, tune) and keeping it on 91 octane. My original goal was to make some where in the range of 680-730whp and be able to hopefully trap between 158-162mph in the half mile (bone stock I did 148mph). But again, with 91 octane (possibly e85 in the future) i'm not sure if these is achievable.

After doing a little more research on here and various other locations, I see that the connecting rods seem to be the weak point on these motors (5.8L).

I understand that every car is different and that it comes down to how the car is driven and the tune that's put on it. But, I wanted to see if there was a consensus on what a "safe" power level would be for these stock connecting rods on the Trinity motor (poll added).

From what I've seen, 650-700rwhp seems to be the "safe" limit for these stock connecting rods.

Thanks again guys for your input.

If you buy a used vehicle, especially a 13/14 GT500, the word "safe" shouldn't be used. First job, get a leak down and compression test to see how healthy the engine is. No point in modifying a $25k engines with a bad or weak cylinder.

As far as being "safe", it's all relative to what you are doing. I personally believe high timing, poor fuel octane and repeated beating on the engine will destroy the rods in the 5.8.

You need to ask yourself if you have the funds to build your engine now while the block, heads and crank are usable ($12-15k) or build with with a destroyed block, damaged heads and crank ($20k++).

Do you have access to E85?

Are you willing to run a high grade fuel additive to signficantly raise octane level everytime you beat on the car?

Do you plan to race at all? 1/4, 1/2 mile or roll race?

For me, I made 875whp on stock rods. That's 24psi and 22 degrees timing on race E85. If I were to hit a 1/2 mile or plan to beat the shit out of it for a weekend, I would've ran 18 degree timing to keep engine load down. I had stock cams so my shift point was at 6300 on my gauge (actual 6500/6600 if you look at logs). Cams are great but they move the power band up and if you want to take advantage of the cams, you may get in the danger zone with rpm. Also to note, I had my car since new so I knew the history inside and out.

91 octane is a terrible high grade fuel but thankfully these cars have wide bands to help keep knock down. I had 91 in Vegas and I ran Torco/VP octanium when I beat on my car. I would use Boostane now but it didn't exist back then.

Im rambling, bottom line, so many variables and risks associated.

 

[Turbo98GT]

Link to what it took to get to 875whp

 

[Norton]

I agree with @biminiLX... ~750RWHP is what I consider "safe," assuming good fuel and no over-rev.

FWIW, I logged ~19K miles and ~30 1/2-mile and 1-mile passes at stock power. Due to scheduling, weather, COVID, etc, I've made only about half-a-dozen 1/2-mile passes while logging an additional ~17K miles with upgraded power (733RWHP / 713RWTQ). I've experienced zero problems, aside from a traction deficit that only got worse at the higher power level, and my car/engine still runs strong.

The importance of quality fuel and never over-revving cannot be over-stated.

 

[1 Alibi 2]

I based my vote on what my tuner considers safe.
Both my 11 & 14 were tuned on the street, for 93 octane.
When the 14 hit the rollers after it was tuned, it put down 818, which my tuner didn't consider safe & de-tuned it to 780..
( tuner used to work for Ford as a calibrator, his shops builds & maintains race cars )
( www.teamjdm.com )
...................................................All bets are off if you run a " canned " tune..
.

 

[1Kona_Venom]

I'm not a tuner, (or tooner), 700+ on 91 with cats and factory exhaust, might be hard



What's your definition of BOLT ONs? Are you going to do headers?
My car in sig is a FULL BOLT ON CAR with 93 at sea level. I have a great above avg tune, and I respect the RPMs. Runs fine with 3:73 gears.

 

[Turbo98GT]

I based my vote on what my tuner considers safe.
Both my 11 & 14 were tuned on the street, for 93 octane.
When the 14 hit the rollers after it was tuned, it put down 818, which my tuner didn't consider safe & de-tuned it to 780..
( tuner used to work for Ford as a calibrator, his shops builds & maintains race cars )
( www.teamjdm.com )
...................................................All bets are off if you run a " canned " tune..
.

What do you consider a canned tune?

 

[Fastback14]

Thank you Everyone for the input.

1/2 mile and standing mile are very difficult due to sustained load but as long as you run good octane and don’t over rev (hardest on rods) I’d build it for 750rwhp and not worry. Now anything can happen and you’ll want to make sure you have a great tuner and datalog but id say go for it.
Id really like to try the Indiana 1/2 mile this year
Good luck
-J

When people say "Over Rev" , are they talking about 7k+ or are they talking about any past 6.5k? I've seen different answers but I feel like the most common answer i've seen is 6.5k.

I'm not a tuner, (or tooner), 700+ on 91 with cats and factory exhaust, might be hard



What's your definition of BOLT ONs? Are you going to do headers?
My car in sig is a FULL BOLT ON CAR with 93 at sea level. I have a great above avg tune, and I respect the RPMs. Runs fine with 3:73 gears.

My definition of Full bolton would be, Full exhaust, TB, Intake, Bigger cooling system (intercooler), pulley. etc

You'll have to excuse me if i missed anything. I'm used to modding LS cars (last car was a H/C/E/I N/A C5Z.

I agree with @biminiLX... ~750RWHP is what I consider "safe," assuming good fuel and no over-rev.

FWIW, I logged ~19K miles and ~30 1/2-mile and 1-mile passes at stock power. Due to scheduling, weather, COVID, etc, I've made only about half-a-dozen 1/2-mile passes while logging an additional ~17K miles with upgraded power (733RWHP / 713RWTQ). I've experienced zero problems, aside from a traction deficit that only got worse at the higher power level, and my car/engine still runs strong.

The importance of quality fuel and never over-revving cannot be over-stated.

Gotcha, similar question that asked above, in regards to over Revving. does that mean going past the factory 7k RPM? or is that anything past 6.5 (or?) ?




and some Side notes:

I'm not 100% set on the 700rwhp #. Again its just a number and would rather have the car running strong than trying to make #'s (same goes with mph).

I've had the car now for 2 years and bought it with 4.2k miles on the clock (now has 25k miles). The car will be registered in Utah since it will be spending most of its time there and will on occasion be brought out to Cali for race events or for the winter months (I rarely drive it now as it is *weekend warrior*).

I would prefer to keep it on 91 (yes i know this gas is crap), but at the moment I'd rather keep it on 91 until I finally make the decision to switch it over to E85.

 

[Fastback14]

I based my vote on what my tuner considers safe.
Both my 11 & 14 were tuned on the street, for 93 octane.
When the 14 hit the rollers after it was tuned, it put down 818, which my tuner didn't consider safe & de-tuned it to 780..
( tuner used to work for Ford as a calibrator, his shops builds & maintains race cars )
( www.teamjdm.com )
...................................................All bets are off if you run a " canned " tune..
.

Yeah, I don't plan on running a "Canned" tune. With all the cars i've had that were tuned, its always been a custom non "Canned" tune. Especially with my vette when I had it.

 

[Turbo98GT]

To be fair, Lund and PBD do canned tunes for 99% of their basic bolt on GT500s. When you tune thousands and thousands of 13/14 GT500, they are about as "custom tuned" as it gets. You'll do a couple logs to verify fueling and you'll be set. $200-$300 and you got thousands and thousands of hours of R&D for cheap

 

[Turbo98GT]

Thank you Everyone for the input.

When people say "Over Rev" , are they talking about 7k+ or are they talking about any past 6.5k?

I would prefer to keep it on 91 (yes i know this gas is crap), but at the moment I'd rather keep it on 91 until I finally make the decision to switch it over to E85.

If you shift at 6300 according to your Shelby shift light, you are actually shifting at 6500/6600. I've verified this dozens of times. So if you shift at 6500/6600 according to your shift light, you are at or near 7k.

I'd recommend using Boostane for when you race. It's 2 year shelf stable and raises your tank octane 6+ points so you are basically running near 100 octane. It's magical and a good safety net for stock rods, especially with 91 octane fuel.

 

[Norton]

Gotcha, similar question that asked above, in regards to over Revving. does that mean going past the factory 7k RPM? or is that anything past 6.5 (or?) ?

I would prefer to keep it on 91 (yes i know this gas is crap), but at the moment I'd rather keep it on 91 until I finally make the decision to switch it over to E85.

Yeah, I don't plan on running a "Canned" tune. With all the cars i've had that were tuned, its always been a custom non "Canned" tune. Especially with my vette when I had it.

If you shift at 6300 according to your Shelby shift light, you are actually shifting at 6500/6600. I've verified this dozens of times. So if you shift at 6500/6600 according to your shift light, you are at or near 7k.

x3.

I'm tuned for 91, but that has more to do with elevation and limited availability of higher octane fuel. For those times when I'm going to push it, I add several gallons of race gas.

I also went with a custom dyno tune from a trusted local tuner with lots of Shelby experience.

I echo @Turbo98GT's advice on shift points. I aim to shift no higher than 6500RPM, meaning I stick with what appear to be 6200-6300RPM shifts. You may not sqeeze every ounce of power that way but, in the absence of a full aftermarket build, you also minimze the risk of windowing the block. I'm good with that trade-off.

 

[2011 gtcs]

Great advice from everyone, be smart about modding your GT500 and run good fuel (E85)

 

[Turbo98GT]

If you are coming from the LS world, there are some distinct differences between how you tune an LS vs a Mod motor. The most important is timing. Boosted modulars/Coyotes don't like excessive timing and a surefire way to hurt things. The DOHC design is wildly efficient and most of our 2000-3000hp cars sit in the 11-14 degrees range of timing at WOT. Even street cars with boost shouldn't see much more than 20-22 degrees at WOT. LS love 26+ degrees but that could be an expensive lesson, not 100% guaranteed to blow up but it wouldn't be something I'd recommend lol

 

[Klaus]

Thank you Everyone for the input.

When people say "Over Rev" , are they talking about 7k+ or are they talking about any past 6.5k? I've seen different answers but I feel like the most common answer i've seen is 6.5k.

My definition of Full bolton would be, Full exhaust, TB, Intake, Bigger cooling system (intercooler), pulley. etc

You'll have to excuse me if i missed anything. I'm used to modding LS cars (last car was a H/C/E/I N/A C5Z.


Gotcha, similar question that asked above, in regards to over Revving. does that mean going past the factory 7k RPM? or is that anything past 6.5 (or?) ?




and some Side notes:

I'm not 100% set on the 700rwhp #. Again its just a number and would rather have the car running strong than trying to make #'s (same goes with mph).

I've had the car now for 2 years and bought it with 4.2k miles on the clock (now has 25k miles). The car will be registered in Utah since it will be spending most of its time there and will on occasion be brought out to Cali for race events or for the winter months (I rarely drive it now as it is *weekend warrior*).

I would prefer to keep it on 91 (yes i know this gas is crap), but at the moment I'd rather keep it on 91 until I finally make the decision to switch it over to E85.

Stock rods will support what you have in mind. You will probably not be over 700 on 91 anyways. I would get meth or run additive as 91 is trash.

Yes 6.5k.

 

[Cobra Therapy]

1/2 mile and standing mile are very difficult due to sustained load but as long as you run good octane and don’t over rev (hardest on rods) I’d build it for 750rwhp and not worry. Now anything can happen and you’ll want to make sure you have a great tuner and datalog but id say go for it.
Id really like to try the Indiana 1/2 mile this year
Good luck
-J

Where is the half mile at in Indiana?

 

[1 Alibi 2]

What do you consider a canned tune?

Any tune you can order via phone or internet.
Any tune in the tuners file, developed on another car & tweeked to suit your needs / mods.
Any tune not developed on YOUR car.
My tuner sells " custom " / file tunes, to customers in the UAE, that can't bring their cars to the shop..
.

 

[Turbo98GT]

Any tune you can order via phone or internet.
Any tune in the tuners file, developed on another car & tweeked to suit your needs / mods.
Any tune not developed on YOUR car.
My tuner sells " custom " / file tunes, to customers in the UAE, that can't bring their cars to the shop..
.

You think bolts on require a custom strategy from scratch?

And you wouldn't use a tune from Lund, VMP, or Palm Beach Dyno that have been refined 1000 times over and only need a few logs to verify its good for bolt ons?

 

[Turbo98GT]

Where is the half mile at in Indiana?

Marion Airport Indiana