RE: One-off Challenger Hellcat X announced
Discussion
"For the Hellcat's supercharger, Dodge reached out to IHI, a Japanese technology giant that is not well known for its work with domestic auto manufacturers, but nevertheless has vast industrial experience going all the way back to the 1850s. IHI's expertise in compressor design has made it a go-to company for outfits like Boeing, GE Aviation, Mercedes' AMG division, Fuji Heavy Industries, Mitsubishi, and Kawasaki, and here Chrysler felt more than comfortable partnering with such a strong engineering force.
At full tilt, the IHI huffer can move 30,000 liters of air per minute running at 14,600 rpm, thanks to a 2.36:1 drive ratio. It does this with high-helix rotational-pull die-cast, PTFE-coated aluminum rotors that displace a tick shy of 2.4 liters every rotation, and for those keeping count, that's 41 percent more volume than the Eaton supercharger in the '15 Corvette Z06. Comparison with the Corvette's LT4 is inevitable, and here a couple of hard facts may prove informative. GM's 1.7L compressor sees a peak speed of 20,000 rpm on the same size engine. Relative to the Hellcat, there is little room on the LT4 for increasing boost via a smaller pulley—it's tapped out—and even if you could overdrive the LT4's Eaton compressor, it's probably a bad idea. That's because GM's air-to-liquid intercooler operates on a high-temp cooling loop with the engine, limiting boost to 9.5 psi, and limiting air density due to its less efficient heat exchanger."
Read more: http://www.hotrod.com/features/1502-we-take-a-hard...
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At full tilt, the IHI huffer can move 30,000 liters of air per minute running at 14,600 rpm, thanks to a 2.36:1 drive ratio. It does this with high-helix rotational-pull die-cast, PTFE-coated aluminum rotors that displace a tick shy of 2.4 liters every rotation, and for those keeping count, that's 41 percent more volume than the Eaton supercharger in the '15 Corvette Z06. Comparison with the Corvette's LT4 is inevitable, and here a couple of hard facts may prove informative. GM's 1.7L compressor sees a peak speed of 20,000 rpm on the same size engine. Relative to the Hellcat, there is little room on the LT4 for increasing boost via a smaller pulley—it's tapped out—and even if you could overdrive the LT4's Eaton compressor, it's probably a bad idea. That's because GM's air-to-liquid intercooler operates on a high-temp cooling loop with the engine, limiting boost to 9.5 psi, and limiting air density due to its less efficient heat exchanger."
Read more: http://www.hotrod.com/features/1502-we-take-a-hard...
Follow us: @HotRodMagazine on Twitter | HotRodMag on Facebook
R8VXF said:
Compare it to the LSA and things look a little better. Can't believe the LT4 went down to a 1.7l S/C. I do fancy upgrading to the 2.3 Magnusson Heartbeat though...
I'm not so sure - the key differentiator is the IHI unit runs a cooling loop that is totally independent of the engine's cooling system. That means that the ECM doesn't de-rate the supercharger due to heat-related detonation like the LSA must - because it relies on "hot-loop" intercooling.Mopar is making 150hp more than GM's LSA with the same capacity. You'd need to do a lot of very expensive upgrading of an LSA to get near equalling that.
Matt Harper said:
I'm not so sure - the key differentiator is the IHI unit runs a cooling loop that is totally independent of the engine's cooling system. That means that the ECM doesn't de-rate the supercharger due to heat-related detonation like the LSA must - because it relies on "hot-loop" intercooling.
Mopar is making 150hp more than GM's LSA with the same capacity. You'd need to do a lot of very expensive upgrading of an LSA to get near equalling that.
The LSA actually has its own independent cooling system, get your facts right. £5k fitted will get you 760bhp. Probably do it yourself for 2.5kish. It basically winds down to new cam, new intake and smaller drive pulley with a remap. Mopar is making 150hp more than GM's LSA with the same capacity. You'd need to do a lot of very expensive upgrading of an LSA to get near equalling that.
peter450 said:
Not sure why a supercharger and TT, why not just strip out the S/C and go twin turbo. Seem an awful lot of extra complexity when the same result could have been achieved with half the bolt on plumbing
I would say the decision was more than likely made by a focus group, rather than being engineering based.They probably came up with the name and the concept first, then got somone to worry about building it.
The article said:
The car is named after the US Navy's XF6F Hellcat fighter, which was also super- and turbocharged.
JordanTurbo said:
peter450 said:
Not sure why a supercharger and TT, why not just strip out the S/C and go twin turbo. Seem an awful lot of extra complexity when the same result could have been achieved with half the bolt on plumbing
I would say the decision was more than likely made by a focus group, rather than being engineering based.They probably came up with the name and the concept first, then got somone to worry about building it.
The article said:
The car is named after the US Navy's XF6F Hellcat fighter, which was also super- and turbocharged.
xRIEx said:
JordanTurbo said:
peter450 said:
Not sure why a supercharger and TT, why not just strip out the S/C and go twin turbo. Seem an awful lot of extra complexity when the same result could have been achieved with half the bolt on plumbing
I would say the decision was more than likely made by a focus group, rather than being engineering based.They probably came up with the name and the concept first, then got somone to worry about building it.
The article said:
The car is named after the US Navy's XF6F Hellcat fighter, which was also super- and turbocharged.
The XF6F prototype was fitted with a turbocharged and supercharged engine. Hence the idea for this car.
Edited by JordanTurbo on Thursday 23 July 10:29
dukebox9reg said:
Makes you wonder why they went for the twin set up on the turbo. Cant imagine with only increasing by 100bhp and having a big SC V8 it would suffer with lag.
Bet it sounds epic at full chat.
given that it's now turbocharged, it'll probably sound far less epic than beforeBet it sounds epic at full chat.
JordanTurbo said:
I'm not an expert in wartime prop aircraft so happy to be corrected, but from what I understand the F6F hellcat aircraft had a two stage supercharger only.
The XF6F prototype was fitted with a turbocharged and supercharged engine. Hence the idea for this car.
The XF6F prototype was fitted with a turbocharged and supercharged engine. Hence the idea for this car.
Edited by JordanTurbo on Thursday 23 July 10:29
the F6F had a two stage supercharged engine, around 2,200hp iirc. The P-47 Thunderbolt had (at least in later years) a turbo-supercharged engine, the B-17 also had turbo-supercharged engines.PanzerCommander said:
JordanTurbo said:
I'm not an expert in wartime prop aircraft so happy to be corrected, but from what I understand the F6F hellcat aircraft had a two stage supercharger only.
The XF6F prototype was fitted with a turbocharged and supercharged engine. Hence the idea for this car.
The XF6F prototype was fitted with a turbocharged and supercharged engine. Hence the idea for this car.
Edited by JordanTurbo on Thursday 23 July 10:29
the F6F had a two stage supercharged engine, around 2,200hp iirc. The P-47 Thunderbolt had (at least in later years) a turbo-supercharged engine, the B-17 also had turbo-supercharged engines.xRIEx said:
From the little reading I've done today, the Hellcat (prototypes or otherwise) never had a supercharger/turbocharger setup, on either of the engines they used (14 or 18 cylinder).
You are quite right actually, on further reading it does indeed have an unsupercharged engine, an 18 cylinder 2,200hp P&W R-2800-10W to be exact, the W designating that it had water-methanol injection (anti-detonation). The Wildcat (F4F) had an P&W R-1830-76 again unsupercharged.It was the F4U corsair that had the supercharged double wasp R-2800-8 (2,000hp).
R8VXF said:
The LSA actually has its own independent cooling system, get your facts right. £5k fitted will get you 760bhp. Probably do it yourself for 2.5kish. It basically winds down to new cam, new intake and smaller drive pulley with a remap.
Forgive me for getting my LSA intertwined with my LT4 - appreciate the correction.Are you stating that you can by a GM LSA motor for GBP5000?
Matt Harper said:
R8VXF said:
The LSA actually has its own independent cooling system, get your facts right. £5k fitted will get you 760bhp. Probably do it yourself for 2.5kish. It basically winds down to new cam, new intake and smaller drive pulley with a remap.
Forgive me for getting my LSA intertwined with my LT4 - appreciate the correction.Are you stating that you can by a GM LSA motor for GBP5000?
R8VXF said:
I believe the confusion may come from the fact that the aircraft in question had what is referred to as a turbo-supercharged engine (at least amongst what I have seen today). A Turbo-supercharger is the technical name for a turbo iirc 
This is probably the case.Either way my original point still stands. IMO the marketing guys will have decided the Hellcat X would be twin charged, and probably already half made that competition advert, long before the engine guys made it a reality.
Edited by JordanTurbo on Thursday 23 July 21:19
Matt Harper said:
Forgive me for getting my LSA intertwined with my LT4 - appreciate the correction.
Are you stating that you can by a GM LSA motor for GBP5000?
You can get an LSX376-B15 crate engine for £5k which is built for forced induction and rated to 1000hp with a warranty. Put on a couple of £500 turbos and you're done. Are you stating that you can by a GM LSA motor for GBP5000?
The LSA blower has a limit and whilst it will make 750hp, heat is the problem. The TVS 2300 will make over 800hp and keeps intake temps sensible. Their implementation of bolting on turbos to a supercharged engine is weird and lazy.
wormus said:
You can get an LSX376-B15 crate engine for £5k which is built for forced induction and rated to 1000hp with a warranty. Put on a couple of £500 turbos and you're done.
The LSA blower has a limit and whilst it will make 750hp, heat is the problem. The TVS 2300 will make over 800hp and keeps intake temps sensible. Their implementation of bolting on turbos to a supercharged engine is weird and lazy.
Would prefer to go with a Maggie heartbeat 2300, much better cooling than the Eaton.The LSA blower has a limit and whilst it will make 750hp, heat is the problem. The TVS 2300 will make over 800hp and keeps intake temps sensible. Their implementation of bolting on turbos to a supercharged engine is weird and lazy.
R8VXF said:
Would prefer to go with a Maggie heartbeat 2300, much better cooling than the Eaton.
They're all Eaton TVS rotor packs. Just a different case and intercoolers on the Heartbeat. Truth is the 2300 will only make about 850hp no matter what version you use, not on pump fuel anyway. God knows I've tried! Gassing Station | General Gassing | Top of Page | What's New | My Stuff