To Turbo or Supercharge

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Slant 6 Nick

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Hello everyone. I just have a question about building a race motor . I am looking to make around 400 ish hp. Would the turbo route be the route to go for this or would the supercharger ( Torqstorm accomplish this? ) I am planning on a 225 bored to 60 over with tons of headwork. Big valves. 114 LSA cam ( if possible ) with 500ish lift ARP head studs , metal head gasket and possibly E-85 with a forged rotating assembly crank K1 rods and wiseco pistons. I’m guessing the turbo will allow me to continuously crank up the boost until I break something or get to the hp I want as the torqstorm limits you to around 18 ? Pounds. Thanks
 
400 hp is a healthy 360

Just saying

kevin-drums.gif
 
I think there’s a company in Australia that makes a manifold for a 471. That’d be pretty cool
 
You set lofty goals for a slant. 400hp is going to be difficult for a slant simply because of head bolt clamping. They just are not able to contain the cylinder pressure needed to make that hp level without serious machine work/modifications. Check out Steve Dulcich’s “quest for slant 6 greatness” on motortrend. His was failing head gaskets around the 300hp mark and was a fairly serious build. I’m not saying it can’t be done, hell I’d love to see a turbo slant make the power. But it’s not going to be a smooth road to get there. Maybe set a more realistic goal (like 250hp) and slowly work up to more hp and find/fix the weak links along the way.
 
I got a V8 car already. I know what you mean though. Would be a lot easier but I wanna be different and difficult lol

doesnt get much more different then this

com.au%2Fwp-content%2Fuploads%2F2014%2F08%2Fsupercharged-slant-6-valiant-aussiespeed-manifold-LR.jpg


all kidding aside, i think a turbo would be the easiest to get her there...but imagine the looks you will get with that scoop popping out the hood in the odd place
 
Hello everyone. I just have a question about building a race motor . I am looking to make around 400 ish hp. Would the turbo route be the route to go for this or would the supercharger ( Torqstorm accomplish this? ) I am planning on a 225 bored to 60 over with tons of headwork. Big valves. 114 LSA cam ( if possible ) with 500ish lift ARP head studs , metal head gasket and possibly E-85 with a forged rotating assembly crank K1 rods and wiseco pistons. I’m guessing the turbo will allow me to continuously crank up the boost until I break something or get to the hp I want as the torqstorm limits you to around 18 ? Pounds. Thanks

14-15 psi basically 2x hp so 200 na hp /6 + 14-15 boost = 400 ish hp, 7-8 psi = 1.5x hp. So you would need 300 na hp. So yes depending on your planned na hp the torqstorm should work fine and be my choice.
 
You set lofty goals for a slant. 400hp is going to be difficult for a slant simply because of head bolt clamping. They just are not able to contain the cylinder pressure needed to make that hp level without serious machine work/modifications. Check out Steve Dulcich’s “quest for slant 6 greatness” on motortrend. His was failing head gaskets around the 300hp mark and was a fairly serious build. I’m not saying it can’t be done, hell I’d love to see a turbo slant make the power. But it’s not going to be a smooth road to get there. Maybe set a more realistic goal (like 250hp) and slowly work up to more hp and find/fix the weak links along the way.

Wasn't he running a high cr like 10:1 and a cheap head gasket?
 
You set lofty goals for a slant. 400hp is going to be difficult for a slant simply because of head bolt clamping. They just are not able to contain the cylinder pressure needed to make that hp level without serious machine work/modifications. Check out Steve Dulcich’s “quest for slant 6 greatness” on motortrend. His was failing head gaskets around the 300hp mark and was a fairly serious build. I’m not saying it can’t be done, hell I’d love to see a turbo slant make the power. But it’s not going to be a smooth road to get there. Maybe set a more realistic goal (like 250hp) and slowly work up to more hp and find/fix the weak links along the way.



i hear you but he had a failed head gasket because it was plain ol head gasket paper fel pro i think . His motor was also high compression built towards N/A
 
14-15 psi basically 2x hp so 200 na hp /6 + 14-15 boost = 400 ish hp, 7-8 psi = 1.5x hp. So you would need 300 na hp. So yes depending on your planned na hp the torqstorm should work fine and be my choice.
. Thanks for the info. Seems to be about the right around for boost to hp on other builds I’ve seen
 
14-15 psi basically 2x hp so 200 na hp /6 + 14-15 boost = 400 ish hp, 7-8 psi = 1.5x hp. So you would need 300 na hp. So yes depending on your planned na hp the torqstorm should work fine and be my choice.
Trust me I know how the math works. It rarely works out in practice the way the math says it does. And it never works that way with belt driven boost. But you go ahead and build a 200 hp na slant and stick 15 pounds on top with a torque storm and see where you end up. Like I said I’d love to see it. I didn’t say it was impossible I said it’ll be a rough road.
 
i hear you but he had a failed head gasket because it was plain ol head gasket paper fel pro i think . His motor was also high compression built towards N/A
It’s all about cylinder pressure. You’ll learn that soon enough. 10:1 and 8 psi will be very similar to 7:1 and 15 psi. It’s all about cylinder pressure. Did I say that already?
:lol:
 
i hear you but he had a failed head gasket because it was plain ol head gasket paper fel pro i think . His motor was also high compression built towards N/A
He failed a head gasket because of clamping load and surface area, or lack thereof.
 
And FYI Steve’s 10.5:1 compression slant with a 220/220 @50 .473 lift cam, “competition ported” head and huge (for a slant) 1.70in and 1.44ex valves made 215hp na with a 4 barrel, offy intake and a Clifford split dual exhaust.
 
And FYI Steve’s 10.5:1 compression slant with a 220/220 @50 .473 lift cam, “competition ported” head and huge (for a slant) 1.70in and 1.44ex valves made 215hp na with a 4 barrel, offy intake and a Clifford split dual exhaust.
Maybe so, but that's the result of tossing a sub-standard head gasket on without pre-planning for the boost, that's all. Copper & Cometic MLS gaskets can be had, as well as ARP head studs, they can easily handle the OP's goal. For supercharged example, see Steve Nitti's Duster. For turbo awesomeness, see Cameron Tilley(slant sixes gone wild on YT), & Will Burns '67 Barracuda. @Charrlie_S can give some 1st-hand pointers.
 
It’s all about cylinder pressure. You’ll learn that soon enough. 10:1 and 8 psi will be very similar to 7:1 and 15 psi. It’s all about cylinder pressure. Did I say that already?
:lol:
And as much as I dislike alcohol as an automotive fuel, the OP did state the intent of running E85, which will be very boost friendly....particularly for the turbo keeping charge temps in check. A lot will depend on fuel delivery type when it comes to that aspect however.
 
Maybe so, but that's the result of tossing a sub-standard head gasket on without pre-planning for the boost, that's all. Copper & Cometic MLS gaskets can be had, as well as ARP head studs, they can easily handle the OP's goal. For supercharged example, see Steve Nitti's Duster. For turbo awesomeness, see Cameron Tilley(slant sixes gone wild on YT), & Will Burns '67 Barracuda. @Charrlie_S can give some 1st-hand pointers.
Yup seen em. And seen the carnage of tilleys engine when it spit out the front and rear mains. I know it CAN be done. I’m simply suggesting the OP make a slightly lower (realistic) target hp goal and avoid some of the headache. If he’s ready for custom pistons, one off rods, handmade sheet metal intake manifolds and the efi set up and tuning to make it happen then more power to him. Like I said I’d like to see it.
 
And as much as I dislike alcohol as an automotive fuel, the OP did state the intent of running E85, which will be very boost friendly....particularly for the turbo keeping charge temps in check. A lot will depend on fuel delivery type when it comes to that aspect however.
E85 is a great fuel choice. I’m curious why you say,
“.particularly for the turbo keeping charge temps in check.”
Turbos do not beat the air and heat it up any more than a centrifugal or (worse) a roots supercharger does. E85 will help the charge air temps regardless of the type of supercharging. Certainly not enough to consider not using an intercooler on the level of boost being discussed here.
 
I'm a stickler for having a neat engine bay. So far, I've not seen any turbo slant builds that don't look like ten pounds of rotten dog ***. That little roots blown one up there ^^^^ looks dang good, though.
 
E85 is a great fuel choice. I’m curious why you say,
“.particularly for the turbo keeping charge temps in check.”
Turbos do not beat the air and heat it up any more than a centrifugal or (worse) a roots supercharger does. E85 will help the charge air temps regardless of the type of supercharging. Certainly not enough to consider not using an intercooler on the level of boost being discussed here.
Draw-thru carb vs mpfi, the turbo body heats the inlet air even w/o boosting, draw-thru w/alky will help cool it. I have no idea what the OP is envisioning here, so just bringing some info to light. 400 hp isn't that lofty an output achievement, but durability as You say, is going to require a lot of attn.
 
Yup seen em. And seen the carnage of tilleys engine when it spit out the front and rear mains. I know it CAN be done. I’m simply suggesting the OP make a slightly lower (realistic) target hp goal and avoid some of the headache. If he’s ready for custom pistons, one off rods, handmade sheet metal intake manifolds and the efi set up and tuning to make it happen then more power to him. Like I said I’d like to see it.
Yes, and that post was really just leading the OP to those vids for inspiration, which they kinda are. But at 124 mph, assuming an as-raced weight of 3,300# for Tilley's car, that would be 500hp...a far sight higher than the OP's goals. Most broken parts are the result of detonation, which I know You know, and is extremely easy to run into like a brick wall when boosting. This is all just to raise the awareness of the OP as to the challenges, but really, E85 & a suitable intercooler should make it doable. Finding room for said intercooler however.......
 
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