twin turbo 427
12-15-2005, 03:47 PM
#22
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700-800 rwhp for a street car is a lot... it really is. My old set up (355/12 psi) made 500 rwhp and that was enough. And now I have 770 rwhp with the new set up. I'll be the first to admit... it's overkill. Granted, it idles fine, I still have the A/C, cruise control, etc., but 1st and 2nd gear are totally useless on the street. Spinning the tires at 75 mph in 4th gear happens all to easily. Don't get me wrong, I love to see a big horsepower car (we all do) and I really enjoy driving my car. 
12-15-2005, 03:57 PM
#23
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I'd probably just do a 348 or 364 (iron). Stock stuff with good rods and pistons. Get some thick deck heads like Dart 225's and a single plane intake if you can fit it. That plus twin 60's will get you past your goal. Get Big Stuff 3 and LOTS of fuel to it.
If you want a 427 for the sake of having 427 cubic inches, go with a GEN1 SBC IMO.
If you want a 427 for the sake of having 427 cubic inches, go with a GEN1 SBC IMO.
12-15-2005, 03:58 PM
#24
Well there's a way to get around not being able to use 1st and 2nd gear...There are several boost controllers out there that you can program a certain amount of boost in a particular gear....so for example you can run 6psi of boost in first, 8psi in second....Or whatever is good for your setup...that way you could hammer it and it would be able to hook without being overkill...I agree that 800rwhp on the street is tremendous but the point that I am stating is that he doesn't need a 427 to get there when plenty of people are doing it via smaller cubes...If your stock crank breaks that will cost somewhere under $500 maybe....If a callies or lunati breaks....That's like $2000...I'm shooting for 800-850rwhp also but I"m just going to be running a PT88 turbo and a 348ci shortblock..I thought about running massive cubes too but then I started looking at what everyone else is running in the 9's....I'm not saying all but I will so that there are alot that are running stock cubes...
12-15-2005, 04:02 PM
#25
Originally Posted by 98turbls1
Do you know how expensive that would be?? I'm just saying that you could probably do the World block and forged rotating assembly for the same price or cheaper..plus isn't the new LS7 like 11:1cr?? That's waaaayyyy too high for FI...
A LS7 with a procharger would be a pretty good reliable setup, he could put a cam in it to help with the compression.
12-15-2005, 04:05 PM
#26
I agree Ryan...that's what I'm going to do...I'm running a GMPP intake with an intake elbow that is custom made and the opening is for an Accufab 105mm...I think the only problem that I see with the Darts are that they only offer 62cc combustion chambers...That sucks cuz I was looking into those for an alternative but I think that I'm just going to shell out the money for the AFRs or some ETs...I also agree with the fact that if he wants to have a 427 just because that he should go with a custom World SBC block...Those pieces would be soooo much cheaper than Gen III equipment
12-15-2005, 04:16 PM
#27
Originally Posted by 427ImpalaSS
which would be a better block to have resleeved an Ls1 or and Ls2 for a twin turbo 427 setup. would ls6 head be sufficient enough to support a motor like that. not trying to go too high in hp just around 7-800. what about ls7 heads I think I read that they would bolt to a ls2 block, would I need ls7 intake also for that. thanks
Bill
Last edited by billreid1@cox.net; 12-15-2005 at 04:25 PM.
12-15-2005, 04:57 PM
#29
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so the world blockis just a regular chevy block no lsx is that right? I am just checking thas the impession I got. no disrepsect 98turbls1 I know I could probably get big power from smaller cubes, but I just want the 427, just for the sake of having 427. I have an ls1 engine I could get cheap now, I just wondered which would be stronger for boost. one of you mentioned the ls7 blocks being out, how soon could that be, anybody have any idea? thanks
12-15-2005, 05:01 PM
#31
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Yes, it is an LSX based casting, but with 6 bolts per cylinder 
and has a lerge bore, and can hold a crazy amount of power. if you wanted to stick to traditional heads then you can simple remove the 2 extra head bolts and use them.
and has a lerge bore, and can hold a crazy amount of power. if you wanted to stick to traditional heads then you can simple remove the 2 extra head bolts and use them. 
12-16-2005, 06:50 AM
#33
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Originally Posted by LTLHOMER
35x inch iron block if you're looking for cheap and reliable. Stock crank, some eagle rods and a good piston and you're easily making what you want to make.
My junk uses stock ls1 block, heads, crank, with a set of used eagle rods and a good piston and it makes pretty good steam and it is almost entirely used parts. Just spend the money on good machine work and assembly.
No sense going off the wall when you're only looking for 7-800 and the extra weight from the block is meaningless.
My junk uses stock ls1 block, heads, crank, with a set of used eagle rods and a good piston and it makes pretty good steam and it is almost entirely used parts. Just spend the money on good machine work and assembly.
No sense going off the wall when you're only looking for 7-800 and the extra weight from the block is meaningless.
I would go short stroke 6L iron block as well.
You have to worry about distortion with the alum blocks at high HP.
4 inch bore iron block with shorter stroke will work very well imo and be able to safely turn serious rpm
Run a thicker deck head like the AFR and you'll be able to handle a ton of boost
12-16-2005, 05:09 PM
#34
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ryanJ,
Dart heads are only .500" decks. No need for BS3 for his build.
blk01ss,
The LS7 has 11:1 cr, and cast pistons... both are NG for FI and would not be reliable just as the factory LS1's are not reliable with 700-800 hp under boost. Also, if your stock crank brakes, it's going to take out your $5000 engine, so it will cost a lot more than $500! A $1500 forged crank is very unlikely to brake at all.
427impalass,
World Products makes both a LSx based block and a sbc based gen1 block (which Ryan was referring to). If you're going 427, get the WP block. By the time you pay for machining, liners, studs, and caps for an LS2 you're talking almost the same amount for the WP block. The WP block should be on the streets by March 06 and costs ~$4k. Do it right the first time.
Dart heads are only .500" decks. No need for BS3 for his build.
blk01ss,
The LS7 has 11:1 cr, and cast pistons... both are NG for FI and would not be reliable just as the factory LS1's are not reliable with 700-800 hp under boost. Also, if your stock crank brakes, it's going to take out your $5000 engine, so it will cost a lot more than $500! A $1500 forged crank is very unlikely to brake at all.
427impalass,
World Products makes both a LSx based block and a sbc based gen1 block (which Ryan was referring to). If you're going 427, get the WP block. By the time you pay for machining, liners, studs, and caps for an LS2 you're talking almost the same amount for the WP block. The WP block should be on the streets by March 06 and costs ~$4k. Do it right the first time.
12-17-2005, 05:39 AM
#35
Very good thread and for wanting to jump to a 427, I'd wait for the new block to be released by World Products as well.
We made an easy 790 rwhp and 750 t lbs of torque with a twin turbo 346 ci Z06 with 14 psi, we know it was making more but there was no way to control wheelspin on the dyno.
http://www.exoticperformanceplus.com...Car.php?car=26
Guys in trunk, one in the rear hatch, and extra straps cinching the rear down towards the dyno. Once the car saw approx 100 mph in 4 th gear on the dyno, the combination of that much hp and tq was too much for the rollers. We found the same problem to be true on the road, even with the extra wide tires the C5 had on it. Bob
We made an easy 790 rwhp and 750 t lbs of torque with a twin turbo 346 ci Z06 with 14 psi, we know it was making more but there was no way to control wheelspin on the dyno.
http://www.exoticperformanceplus.com...Car.php?car=26
Guys in trunk, one in the rear hatch, and extra straps cinching the rear down towards the dyno. Once the car saw approx 100 mph in 4 th gear on the dyno, the combination of that much hp and tq was too much for the rollers. We found the same problem to be true on the road, even with the extra wide tires the C5 had on it. Bob
Last edited by Exotic Performance Plus; 12-17-2005 at 05:45 AM.
