Debating on single or twin

03 Zinc

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Hey guys lets start off with I am new to this forum. I have a 03 zinc yellow cobra and I have maxed out my stock eaton blower. I am in the process of trying to decide if I should keep the blower and run the twin turbo kit from Hellion, or snatch it off and run a big single. My goal is to reach 800Whp on pump gas. Sorry for the plain post, they will get better as I do this more.
 

Weather Man

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800 on pump is a grenade waiting to go off, switch it over to E85.

I like single setups myself.
 

03 Zinc

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800 on pump is a grenade waiting to go off, switch it over to E85.

I like single setups myself.


How big of a turbo do you think I should run to comfortably make 800. Also I have been thinking about running E85 as well I just need to convert my fuel system. Another question is which kit did you use? Custom, Hellion, CG Fab or what?
 

Weather Man

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My 67 was comfortable at 700, it ended up being a custom fabricated setup.

I would say a 76 for 800 comfortable.
 

tt335ci03cobra

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If you'll keep the long block stock, get a set of arp studs and some decent head gaskets to keep it together.

A single 76 with an 80 hotside will have the flow for 800whp at about 18-19psi with a very nice high flowing system.

Twin 58/60's would also work well.

It's best to build up the head/cam combo and freshen the longblock with a nice 9.3-9.8/1 piston (for a pump gas car don't go much higher). These engines are 14 years old now so rings and valvetrain do get past their prime. I feel safer running lower boost on a stronger/more efficient engine than higher boost on an older good but stock engine.

I put 800whp down with pump gas running 9.3/1 compression through 62's by building the heads and cams fully. I'm running a hair less than 12psi. A previous twin 57 combo with a custom cold side and stock 4.6 longblock made 756whp on 15psi with a Sullivan intake and pretty choked exhaust.

Tuning is crucial as is cooling and fuel. To do a reliable 800whp pump gas car isn't very cheap or quick process unless you're very handy.

Thing is, unless you have built suspension and matching electronics to optimize acceleration for the first 330ft, you won't be much faster than a 650-700whp setup. It's much easier to build a 650-700whp pump car, and then run 110 for 800whp.

Just going from experience, these builds get pricey when you try to make reliable hp on pump gas.

Kit wise, single is easier to make custom. Twins are more involved, but Caleb from CGfab has a great header and down pipe. Cold sides are pretty easy either way. Don't go too big on the intercooler, and try to switch a Lincoln mk8 fan from 93-98 in. They work great.
 

03 Zinc

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Yeah I currently have 9.5:1 pistons, comestic head gasket, arp studs, stage 3 comp cam, comp springs and retainers, valves freshened up les that 5k ago. Bigger mass air, ported eaton, 60lbs injectors, full suspension, aluminum drive shaft, bbk header, 3inch x pipe and 3 inch magma flow. It is already built I just need the fuel system now. And decide what turbo I want to do
 

s351

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Throw some water/meth on it for safety if your shooting for 700+ don't use it for the timing and boost just use it as a safety blanket for the pump gas.
 

tt335ci03cobra

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Do you have turbo cams or blower cams? They won't work well if they aren't turbo grinds.

That's a healthy list, you'll probably need a Sullivan intake to make 800whp on pump gas.

A single 76/80 should get you there.

Twin 58/60's is my vote. It's more involved though. You have a lot of cam to work with if those are turbo grinds, port the c heads to 325-340cfm range on the intake side. You'll probably need 7250-7500rpm.
 

Nightmare302

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Ditch the idea of pump gas, save a ton of money and still make the power you want. You can easily make 800 with e85 and you don't need to spend the thousands needed to rework the heads. Don't touch pump gas unless you plan to have a standalone. One bad tank and your entire build is up in smoke.
 

tt335ci03cobra

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^so damn true. I get people asking me why I only run 11-12psi/don't run 15-17psi on pump gas.... It's a crap shoot.

I fill at shell only. Still have no desire to run much any boost on pump gas. If my car made 300whp on 12psi that's still all I'd run on pump gas. I've ran 15psi before and it felt like every tank other than She'll gas was slightly pinging.
 

tt335ci03cobra

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(On these engines of course. My ecotec daily driver runs 22psi but the turbos a stock tiny little bugger)
 

03 Zinc

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Do you have turbo cams or blower cams? They won't work well if they aren't turbo grinds.

That's a healthy list, you'll probably need a Sullivan intake to make 800whp on pump gas.

A single 76/80 should get you there.

Twin 58/60's is my vote. It's more involved though. You have a lot of cam to work with if those are turbo grinds, port the c heads to 325-340cfm range on the intake side. You'll probably need 7250-7500rpm.





They are blower cams... I bought those cams when I had no intention of going turbo, however things have changed and now I want to get turbo ones....
 

tt335ci03cobra

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98 cobra cams are a great option if you want to put off custom cams. MMR makes a great cam. You can also send NASVT a pm, he makes excellent cams.

Comps stage 3 turbo cam is very good, but it more of a 2+, very safe, idle's nice, etc. depends on your goals/use of the car.
 

tt335ci03cobra

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You can probably sell the blower cams for $500-800, that'd take care of a huge chunk of the price of turbo grinds.
 

03 Zinc

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when I have it all taken apart I will see what I decide. I do appreciate all of the advise though.
 

ruthless

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I know this is old but...
Not sure why all the 93 pump gas hate in this post. I made 750rwhp with my custom built kit running the old 76mm billet wheel precision turbo on the factory engine. That was on 16psi with the T56 trans. I have raced as high as 18psi for years with the th400 setup in the car and hot lapped without an issue. So with some math I would have been well over the 800rwhp mark with the T56 on 93 at 18psi.
Now if I ever get my current build finished on the built engine I will not be running 93 or E85. The E85 around here is junk and I will need something better then 93 to get to where I want but we are talking 1000rwhp with a th400.
 

Nightmare302

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I know this is old but...
Not sure why all the 93 pump gas hate in this post. I made 750rwhp with my custom built kit running the old 76mm billet wheel precision turbo on the factory engine. That was on 16psi with the T56 trans. I have raced as high as 18psi for years with the th400 setup in the car and hot lapped without an issue. So with some math I would have been well over the 800rwhp mark with the T56 on 93 at 18psi.
Now if I ever get my current build finished on the built engine I will not be running 93 or E85. The E85 around here is junk and I will need something better then 93 to get to where I want but we are talking 1000rwhp with a th400.
Because pump gas is dangerous at best at that power level. It's incredible easy to kill an engine when you are pushing it that hard on pump gas.
 

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