Small Turbo on stock L29 454?

[Supercharged111]

Making an assumptions that low to mid 400's would be enough. Adding turbo set up just to go from 400-450 mark to 500 to me does not seem to be worth the effort.

Agreed, I was speaking of slapping a turbo on an otherwise stock setup to hit 500/600+. Again, it's a all about how you want that power delivered.

 

[Chilledspode]

Gm 8.0l version(l29 heads) was good for 430hp and 530 ftlb torque by 3k rpm. 7.4l should be not far off even with stock heads. Turbo adds a lot of complexity for not much gain if staying below 500hp level.

Those numbers line up with my limited experience. I am not a motor guy but I understand the basics. The very experienced guy who built the 496 for me discovered the that intake was one of key limiting factors to making hp on the 99 mpi vortec setup - he did what he could to improve flow at the intake and iron heads but couldn't get much beyond 800cfm. Accounting for losses, tuned on a chassis dyno with about 9.2:1 he figures we got close to 500/500 at around 3k at the motor. I asked for strong bottom end motor that would run on pump gas that would keep all the stock systems. I am very happy with the results - lots of torque driven giggles at tip in .

 

[yevgenievich]

Agreed, I was speaking of slapping a turbo on an otherwise stock setup to hit 500/600+. Again, it's a all about how you want that power delivered.

I really want to get to a reliable 900hp range on a set of twins with a built 8.0l, just not sure if I can grow that much cash on the money tree.
I did just sell the good 8.0l and about to drop off the not so good one for rods and pistons upgrade.

 

[Christian Steffen]

I've kicked around the idea of going from Whipple to turbo as it's easy to get 10# from a turbo and that would wipe the floor with what I have. The big question is at what RPM would it spool? I'd want full boogie by 2,000, but wonder if it would choke the top end? Probably not since it's done at 4500.

You may be hard pressed to get full boost by 2k, but you'd probably get close. You may not love the little "lag" you'll get vs your whipple, but being able to get an actual intercooler in the mix would probably be nice.

As far as NA 496 vs boosted 454 goes.. the boosted truck will have a much broader torque curve than the stroker, assuming boost comes in down low anyway. The biggest benefit I see with the stroker is avoiding complexity/no fitment issues.

 

[Supercharged111]

You may be hard pressed to get full boost by 2k, but you'd probably get close. You may not love the little "lag" you'll get vs your whipple, but being able to get an actual intercooler in the mix would probably be nice.

As far as NA 496 vs boosted 454 goes.. the boosted truck will have a much broader torque curve than the stroker, assuming boost comes in down low anyway. The biggest benefit I see with the stroker is avoiding complexity/no fitment issues.

When it's pushing 20,000# the instantaneous response is somewhat moot, especially compared to a properly sized responsive turbo. If it makes more than 4# anywhere it's going to beat what I have now, especially being intercooled. That said, a pulley is on the to do list to get both blowers at their max rated RPM by WOT shift RPM.

 

[Christian Steffen]

When it's pushing 20,000# the instantaneous response is somewhat moot, especially compared to a properly sized responsive turbo. If it makes more than 4# anywhere it's going to beat what I have now, especially being intercooled. That said, a pulley is on the to do list to get both blowers at their max rated RPM by WOT shift RPM.

That's a good point, honestly there probably would be almost no lag with a trailer, and like you said proper sizing is everything.

Since you already have the whipples, hopefully dropping the pulley size will do enough.. Maybe add W/M to try to control IATS?

 

[Supercharged111]

It'll bump them 1psi max. W/M would involve some fab, but might help a bit. As was pointed out before, I could use the nitrous function of the 411 to help control when I run out.

 

[8flat]

My machinist talked me into ditching the genV and going with a MarkIV block (stronger) and 049 heads for better airflow in the higher RPMs, although my cam designer has shown in his software that the peanut port heads make great power and torque down low.

I'm going with a stroker 496 for simplicity, around 440hp and just under 600ft lbs of torque. Final cam design isn't done yet but we're close.

If you guys want cam advice, I know a guy.........

 

[Schurkey]

The most important bit of "cam advice" for a big-block is to make sure you buy a Gen 6 "Step-Nose" roller cam, along with the OEM thrust plate, and a timing set suitable for the bolt circle on the cam. The older blocks will need "retrofit" roller lifters. Thus the advantage of the Gen 6 blocks. I've seen Mark IV blocks that aren't drilled and tapped for the thrust plate--but the bosses are there ready to be machined. (Some aftermarket blocks don't have the bosses.) MOST Mark IV blocks are drilled and tapped already.

Buying a flat-tappet cam in this day and age is just crazy. If you INSIST on buying a flat-tappet cam, pay the ~$120 extra for case-hardening. [EDIT] Nitride treatment.[/Edit] Worth every penny.

 

[LC2NLS6]

I like the idea of get a gen 6, slap a bigger cam/springs, performer rpm intake, catback, and tune on it and let it eat.