RW99

I'm open to either turbo or supercharger, but I need to pick one in the next few weeks.

I'm thinking that on my stock bottom end, a turbo would be the better choice. Won't the better efficiency of the turbo mean that I could attain the desired rwhp while requiring less power from the crankshaft? Less strain on the pistons/rings/etc?

Am I an idiot to do any sort of FI without upgrading the critical stock (80k miles) internals? How much would this cost with typical labor charges?

Plan is to use 72cc AFR 225 heads, 224/224/114 cam, FMIC. Goal is 550 rwhp smog-friendly.

Opinions/info most appreciated.

Thanks, Rich

Got Me SOM

iTrader: (2)

a turbo will be more efficient yes, but not any easier on the bottom end.

your power goal with the heads is very easily attainable.

personally i like the supercharger since power is more linear whereas turbo's give you all the power in a burst, that will cause tire spin.

either way you go you can't go wrong.

MelloYellow

Good luck.
I thought the 72cc AFR 225's were on hold?

RW99

Huh? Anyone? Texas Speed, you out there? Mello, you have any further info on the AFR 225 72cc's?

KissMySSo1

iTrader: (2)

They shouldn't be. I ordered a set last week and they told me 4 weeks

mongse

iTrader: (2)

Read the FAQ man...
https://ls1tech.com/forums/forced-induction/208864-turbo-faq.html

RW99

FAQ already read; I'm looking for specific answers and experience, thanks. Mainly from people have gone to FI power levels of 550 rwhp with the stock bottom... and how many of them have had problems.

By going to 72 cc AFR 225's I hope to lower compression for increased safety, too.

And I'm looking for informed opinions on the turbo vs. blower question: given the fact that an engine that is supporting a blower needs to work harder to spin the same boost... while the turbo is basically free boost. Seems to me that a guy can reach his power goal with less engine effort by choosing the turbo route.

Wnts2Go10O

iTrader: (12)

550, while it can be reached the bottom wont last too long with that stress. pop some froged pistons in there so she lasts longer. escpecially with 80k on the clock.

jv_Z28

iTrader: (1)

Hey, I have a 98 Z28 with about 82k miles on it, I got the STS turbo kit with the water alky. The LS1 was completely stock except the upgraded fuel system and injectors (which is a must) I was making over 410 to the rear wheels (through a moser 12 bolt) with no alky on 5psi. I had a front mount intercooler installed and ran 8psi with the water alcohol and and made a lot more power, but I never dynoed it hard to compare it to but I pulled on 2, 2004 vipers at different times. But just as we were done tunning it on 10psi on the way home at wide open throttle a small piece of my #8 piston cracked and shredded my cylinder sleeve.

RW99

jv-- that's useful info. Was your 10psi tune done with A/F logging? In other words, did you have reason to believe that your A/F should have been OK when you blew your piston up? Any sign of damage to other pistons?

condolences on your loss, and thanks for chiming in.

MelloYellow

My bad on the AFR 225's.
It's the 62cc that was delayed.

Good luck!

MelloYellow

True, the motor has to make another 75-100HP to drive the blower, but the Turbo has a harder TQ hit with a broader powerband while the SC comes on smoother. Engine wear should be even.

But a Turbo definitely is harder on the clutch/trans/rear. If you'd like to minimize the SC engine wear/snout load on bearings you could buy a nicer ATI NASCAR style Damper.

RW99

Mello, when you say that the turbo is definitely harder on the clutch/trans/rear, do you mean that the TQ hits so hard that the driveline suffers? It's hard for me to imagine that this increased TQ/stress once the car is already in motion would be any worse than the TQ/stress that the driveline suffers every time the car is launched from a dead stop. To me, once you've upgraded the rear end, it's cheaper to deal with driveline parts than it is to deal with engine internals.

The SC wear on the bearings is often mentioned; do you think the damper is a fix or a bandaid? Is this wear even an issue if we're talking about a car driven 3000 miles/year?

Thanks again for all opinions.