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Hellcat Engine vs. Trinity Engine

44K views 86 replies 25 participants last post by  JBS$ 
#1 ·
This thread has nothing to do with the GT500 or the Challenger/Charger, I simply, for conversation and entertainment purposes, want to compare these two monstrous engines. I'd like to hear from those of you who really know your stuff about engines. I can read the article and while I do understand a lot of stuff, I know that most of you out there know far more than I do about engines, engine parts etc.

So here are the two articles I read, the first on the Trinity Engine, and the second on the hellcat engine.

2013 Ford Shelby GT500 Trinity 5.8L V8 - Power Of Three - 5.0 Mustang Super Fords Magazine

And here's the hellcat engine article

We Take A Hard Look At Dodge s Paradigm-Shifting 707hp Hellcat Hemi

The notable few things I was able to gather from this with my limited engine knowledge is, the Hellcat has a more efficient, all around "better" supercharger." The combustion chamber pressure on the Trinity engine is higher at around 2,000psi, while the Hellcat see's pressures just under 1,600 psi at max load. But the pistons in the Hellcat engine can withstand up to 22,000 psi??? Am I reading that wrong, that seems way off to me. The Hellcat engine has a higher compression ratio. Seems the Trinity engine also has an electric pump to pump coolant through the intercoolers, but it doesn't specify how much, whereas they say the Hellcat can pump 12 gallons of coolant through the intercoolers every minute.

For those of you that know better, how would you compare these engines? Which engine do you believe is "better" built? Which do you think can withstand the most power the longest? Are there things about one that is clearly better than the other? I'd like to hear your honest thoughts and if possible, without a Hellcat bias :)
 
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#6 ·
I now see I need the Evelynn Wood speed reading course because it took me 10 minutes to read the first 2 pages on the 5.8 and I need a break
 
#7 ·
To help facilitate the discussion:

Trinity (Mustang) / Hellcat (Challenger)
5.8L (355 cu-in) / 6.2L (370 cu-in)
662hp @ 6,250rpm; 631tq @ 4,000rpm / 707 @ 6,000rpm; 650tq @ 4,000rpm
all-aluminum / cast iron block; aluminum heads
Dual Over Head Cam / Single Over Head Cam
4 valves per cylinder / 2 valves per cylinder
14psi boost / 11.6 psi boost
no variable cam timing / variable cam timing
6,250 (7,000 overrev) rpm / 6,200prm
5w-50 full synthetic / 0w-40 full synthetic
2.3L TVS Eaton blower / 2.4L IHI twin-screw blower
54.8lb injectors / 57lb injectors
9.0:1 comp ratio / 9.5:1 comp ratio
3.68 x 4.165 bore-stroke (long stroke) / 4.09 x 3.58 bore-stroke (short stroke)


6.2L Raptor engine can't fit in the Mustang.
 
#15 ·
From what I gathered from researching and from what others have been saying on the other site I'm waiting for permission to post the link to, they are both monsters. The Hellcat has a more efficient supercharger with better cooling, all while running less boost so the Hellcat should be more consistent and much less prone to heat soak. Both engines use powdered metal rods, which is the weak link in the Trinity engine and will likely be the weak link in the Hellcat engine as well. Only difference is because the Hellcat engine doesn't rev as high, and the stroke is less on the Hellcat engine, the Hellcat rods should be able to support a little more power than the Trinity engine, as long as the rev limiter isn't raised to high. The max recommended power on the Trinity with stock internationals is about 750rwhp. So with the Hellcat, assuming the rods are the same strength, which we simply don't know yet, I'd guess about 800rwhp should be okay, as long as the rev limit isn't raised substantially. Also, the Trinity engine should be able to run more boost because of it's lower compression ratio. While the Hellcats supercharger can run more boost more efficiently than the Trinitys roots style blower, the engine's higher compression ratio will keep you from being able to do so on pump gas.

I'll post the link with that and more information as soon as a mod says I'm allowed to. I don't know if it breaks any rules or not.
 
#24 ·
That's my guess, assuming the rods are the same strength, due to the lower piston speeds. I'll post the speed differences around 12 when I get my lunch break. There really is no telling for sure until people test and tune these cars. I'm thinking you should be able to make 750rwhp reliably. Maybe 800, who knows until they've been out and running with mods for some time.
 
#33 ·
Okay, here are some quotes from the other website with this discussion going on...

This first guy is a little disgruntled, but he makes some good points so here it is

93 347 Cobra;14692311 said:
I had a talk with an engine designer this last fall about powdered metal rods. The granular structure on powdered metal means it isn't nearly as strong as traditional drop-forged rods but the PM rods are fractional in cost to produce which is why they're favored by manufacturers who need huge volumes of them. Re-formulated or not we won't be seeing Hellcats running "four-digit power" as the delusional are ever so fond of repeating. The Hellcat rods may or may not be marginally better than the GT500 rods but people running around believing Hellcats can add 300-horsepower with ease are just dumb.

I swear the absolute stupidity over the Hellcat makes me want to puke. The Charger gets tested at minus 1900 feet DA at temps right around freezing and runs some fast times and people start falling all over themselves. The Goodyears on GT500s aren't even possible to drive on in the winter so the ignorance of some in regards to how much of a difference there is in power production on a very cold day can be excused. Supercharged engines run exponentially better in cold temperatures. I wouldn't be surprised if my old '03 Cobra picked up 30+ rwtq and 30+horses on a cold morning. Plus on a long pull like a standing 1/2 mile or standing mile the IAT2 temps remain very cold the whole run and a supercharged engine won't pull timing over the course of the run resulting in dramatically better times.

The Hellcat engine's main advantage is variable valve timing which extends the powerband in both lower and upper revs. The Hellcat runs 9.5:1 base compression which means not as much boost can be tolerated on pump gas once the ECU gets cracked. Its 2.4 twin-screw is a bit undersized for a screw-blower, none of us would ever spend money to upgrade to anything less than a 2.8 or 2.9. It'll be a bit more efficient than the TVS at boost levels above 16 or 17 pounds but the Hellcat will need higher-octane race gas at 14-15-psi and above due to that base compression.

The GT500 performs pretty well with a hugely restrictive resonator, undersized throttle body, and lazy 3.31 gears. I'll take the 600+ pound weight advantage all day long. Res delete, throttle body, gears, and driver mod= Hellcats won't have a chance.

Snoopy49;14692381 said:
As far as the 5.8L is concerned, the long stroke (4.165") and the high piston speed at 6250 rpm (4321.1 Feet Per Min) helps contribute to rod failures and other potential rpm related issues.
By comparison, the 6.2 HC piston speed at 6250 rpm is 3714.2 Feet Per Min with a stroke of 3.58".

Has anyone run across the rod length and rod to stroke ratio of HC engine?
The rod length on the 5.8L is 6.658" ctr-ctr with a rod to stroke ratio of 1.6.
2011 gtcs;14692518 said:
Correct RPM does kill rods, that's why as I have increased HP I shift at 6,200 rpms. I just hope once you hellcat boys start tuning them you don't start thinking you can shift at 6,800rpms.
Snoopy49;14692648 said:
GT500 = 4839.73 Feet Per Minute @7000 RPM
HC = 4159.96 Feet Per Minute @7000 RPM
 
#38 ·
Stock 13-14 GT500 max boost is 11 psi. The gauge reads a little higher. Ford actually has a average of 9-15 psi... every one Ive ever done a base line on was right around 11psi.. Now there is a lot of room for that little TVS. Just like I am sure there are room for the ihi in the HC. The hellcat also runs a electric pump, and separate cooling systems from the super charger and the engine. The draw back, the HC has a tiny heat ex changer vs the shelby, In time, some one will develop a better one for the cat, just like they did with the snake. The only real draw back to the HC right now is lack of tuning.. from what ive seen the Apache engine and Hellcat engine are roughly the same dimensions. I.E. Headers are ready to go. Minus the exhaust valves. The balancer should JUST be a pulley change, as the crank snout and front of the engine is the same as the 6.4. There are a lot of carry over parts from the SRT8 6.4 and the HC 6.2 That will be a leg up to the 2017 GT500. The rumor I keep hearing is TT 5.2 for the Shelby. that's going to build HP in a whole different area of the power band than the HC, ZL1 and even the Z06. and what ever else gm stuffs that LT4 into.

We will just have to wait and see what the HC can do.. I've put together 800/800 to the wheel corn fed shelbys.. just bolt ons. only thing I changed internally was the spark plugs.. everything else was TB, pulleys and fueling. And that is dialed back to a conservative number. Guys with kenne bells can turn out 850 with the just the bolt on blower.. I've seen guys dyno 900 to the wheel on stock internals. Thats not going to last long, but its possible. So lets wait till the ECM gets cracked, and see what kind of insane numbers this kitty can produce!
 
#46 ·
Do you feel like it's faster now, the reason I ask is everyone I have talked to, says after 1000 miles on there charger rt, the car really wakes up,, like night and day, my brother proved this three times, and the guy I work with told me the other night about his,I told him when he got it, wait until you hit 1000 miles, it's going to feel like a different car,
 
#47 ·
Tough to say as the power/car becomes more manigable with seat time. It does seems to break loose easier in street mode now though. Sport and or track is truly silly to be running for daily use as Sport mode alone is a feathering feat of epic proportions. The shifts are hard enough to wheel spin at 50+ could only imagine track mode.

I'll know more once I track it some. Just gotta find the time.
 
#48 ·
I really love the HC but buying a 1st year car that is so highly advanced is a bit of a risk...
Ford has been using forced induction on the Cobra/Shelby since 2003. Stock 2003 Cobra's still holding up after 10+ years.
You just contradicted yourself there.

So is it a risk, or not? The Terminator engine was highly advanced in 2003...and still ticking.
 
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#49 ·
Sure the 03 Cobra was a bit of a risk I knew that when I bought one new in August of 2002. At one time I had two (coupe & convertible). 03's had first run issue like head tick, not enough threads in the sparkplug wells, smoke at start up, etc. The HC is the same bit of a risk..

We were comparing a new HC engine to a Gt500 "trinity" engine. To me the "trinity" has 10+ years of ground to stand on with the 99+ Lightning, 03/04 Cobra, FORD GT, and prior GT 500 motors. What was Dodges' last factory SC engine?
 
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