candlelit

iTrader: (21)

I'm pretty sure my brother is going to buy the Firehawk as a roller from me. So we're discussing new build options for him, because I think I'm going to sell my 8.7:1 CR 347 that's in it. We're debating whether we should do a 347 procharged, LQ4/LQ9 iron block procharged, maybe 408 procharged, or a NA motor... 402 LS2, 408 iron, 416, etc. He may drive it 5 times a week for awhile, but eventually only about twice a week it'll be driven. He's also a fan on the "big cam" sound. I know how much money he's got to spend matters on what to do, but right now I'm leaving that open. Power goals are at least 500rwhp, 475+rwtq. This will be through a 6 speed. Eventually there will be a 9" in future mods.

How much $ difference will it cost between a built 347 & built 408, with same heads/cam/etc? If only like $1000 he would rather go with the bigger motor. Also, what CR for optimal power on a 402/408/416 NA setup pump gas?

As for the difference of either NA or Procharger, NA gives you the idea that you have to change your build to increase power numbers quite a bit. So I'm afraid he'll be like everyone else and want more power after 500rwhp, especially since he will already be spending money on bigger injectors & fuel pump upgrades. Is it worth the cost difference to go with a smaller LS based motor & procharger, or should he use that extra money for better flowing heads/intake?

N4cer

iTrader: (11)

I've had a 408, and have to say: cam sound is nice, and the power is fun, but it's just plain inferior to FI. With forced induction, you can run a milder cam, make more power, and make more power for your money.

Unless you want to run some kind of crazy low times, I think you'd be fine with a 346 and FI. After all, stock cube FI cars go 9's daily.

candlelit

iTrader: (21)

thanks for the input.

anyone else?

dankl

iTrader: (1)

It's all about preference. If he's a fan of FI, than N/A won't do it for him. Or vice versa...

I was debating the same scenarios myself, as I just blew my bottom end recently. My decision was swayed by the fact that I had bought a bunch of "goodies" for my N/A LS1, that can be put to use in a bigger motor. Whereas if I wanted to go FI, I would need to start from scratch and get new heads, new intake, etc...

I'm going with the N/A Iron 418cid LQ9 build. This can put my heads, intake/tb, etc... to good use, plus be a nice increase in power output. Mine is going to be a DD for awhile too.

Planning for around 11.4:1 SCR

General Jack

iTrader: (4)

You said he likes the big cam sound... I do to, and I'm a hair trigger away from building an L92 427 with TFS 235s, FAST 92/92 and a very big cam. For me, ease of tuning and reliability are the other big selling points of N/A.

05JUDGE

iTrader: (26)

Check out my sig. There are links to my mods and videos. I have a LS3 427 and couldn't be happier. I had actually bought a 122 Magnacharger at first and then decided to just go N/A. The way I see it, it actually worked out cheaper to go N/A than FI. You end up making money back from your original motor and any other motor parts you get rid of. I bought a short block and heads and did all the labor myself. I think I came out right around $7k when all was said and done. That includes headers, exhaust, tune, etc....
Plus I have an A4 and made 502rwhp unlocked and 536rwhp locked. You would see more than that with an M6 for sure. Plus You'll have a 10 second car easily.

It's hard to make that power on FI without having other mods and the risk of damage on the motor eventually. Not to say it can't be done, but from my experiences, and seeing people try to make big power on FI, it usually take more money.

tektrans

iTrader: (23)

I'm partial to N/A.
FI is always more expensive because you have to build a strong bottom end to run any kind of boost reliably so you're building the motor + all the FI stuff.

Nothing like boost though when it comes to making power, that's for sure!

candlelit

iTrader: (21)

that GTO is one nasty car!

I was thinking about selling him on swapping out the heads & head gasket to bump the CR of my 347 to apprx. 9.3:1 and all he would have to do is buy the kit, no worry about pulling motors/etc. BUT... I came across some Procharger dyno/track numbers and it seems the average 347 is running high 10's @ mid 5xx rwhp & only about 630rwhp @ 12-14 psi. Plus tq isn't very high on those ls1's. I seen a ton of 408's run 10's all day, with near 500rwhp & 470+tq with good set of heads, nasty cam, & fast intake. Like someone else mentioned, reliability & easier to tune, plus perhaps saving some cash will make me wanna sway him toward NA.

Hmmmm. Let's say I sway him toward a NA build. What CI would you guys recommend to be the most power for the buck? I know aluminum saves only about 40-70 lbs, so it's not that big of a deal to go iron.

candlelit

iTrader: (21)

hey, how much does that car in your sig. weigh?

05JUDGE

iTrader: (26)

I would check out all the builders and see what they offer for the money. I did quite a bit of research before I bought my 427. I went with Texas Speed and am very happy I did. Customer service was great and I'm happy with my product. The price was also very reasonable. I'm sure there are plenty of engine builders on here tha would give you a great deal though.

Oh and it's too bad I just moved from Oklahoma. I lived in Perry...like 20 minutes from Stillwater...I could have helped.

candlelit

iTrader: (21)

^ I think I remember talking to you a couple of times on here before. sorry to hear you left, but Montana is a gorgeous state! hope you're enjoying it up there.


one more question guys... is it worth paying the extra dough going (408 about 500rwhp) vs a (346/347 pushing about 470rwhp)? I've watched some vids & cars like that seem to run pretty similar, nothing dramatic. I mean like less than 1 full second difference in a 1/4 run.

05JUDGE

iTrader: (26)

I wish some more peopel would jump in and give some more opinions. I was just looking at Texas Speeds page and they have the 346/347 aluminum short block at $2899.99 and they have the 408 iron short block at $3475. To me it's well worth the extra $500. But that's just my opinion.

dankl

iTrader: (1)

Iron block LQ9 bored to a 408 if you want to use n2o or some other power adder. You can go up to 418 if your not hitting it with any juice. The longer stroke for the 418 makes more torque, but not good for anything other than N/A. Both these will produce great RWHP #'s plus high torque #'s, compared to building up the 346.

Plus, to get 470 RWHP out of the 346, it will not be the best "street" car. To get that power out of the 408+, you don't even need a big cam. You can keep it a lot more "driver friendly" with the bigger cubes.

1.8t

People spray 4" stroke stuff all the time. Its the overbore on the 418 that is cited as the reason not to spray, even though I am sure many still spray them.

dankl

iTrader: (1)

The 418 I was referring to is the 4.030" X 4.100". Longer stroke no good. If you go 4.030" X 4.000" (408cid), you'll be fine to spray.

1.8t

I was talking about a stroked LS3. 4.070" (.005 clean up) x 4.000", 416ci as apposed to a 4.080" x 4.000" 418ci engine. And now that I think about it, they were probably referencing the 418ci motor you were describing w/ regard to no power adder....I wouldn't think a .010 overbore would be the deciding factor for power adder versus n/a.

05JUDGE

iTrader: (26)

The only motor I have ever seen anyone say not to add FI or nitrous to was the LS3 427 like I have. I know Texas speed builds the 418 just for the purpose of adding FI or nitrous. That's why I went with the 427 because I don't ever plan on using either.

dankl

iTrader: (1)

^^^I'm not sure, but I think the Texas Speed's 418 is derived from the LS3, as I think the stroke is still 4.000". The one I was referring to is the LQ9 build. I know for a fact that they say don't use a power adder on the LQ9 418 due to the stroke length. If you keep the stroke at 4.000", then you are safe to use a power adder.

05JUDGE

iTrader: (26)

oK...I see what you are saying now. Totally agree. I think also, just like my 427, that with a longer stroke like the LQ9 would have, that the pistons have a higher ring land and also a thinner piston face, not making them "ideal" for power adders. I'm sure if it was set up correctly it could take the abuse. I personally wouldn't risk it.

LSWONGTO

iTrader: (3)

Well it all comes down to the owner's like's and dislike's. I personally love a nasty NA motor but FI motors will always have more power. I have no doubt that a 408 with Trickflow 225s/ Vengeance ported Fast 92/ a low 240s cam/ and 1 7/8 headers would have no problem putting down over 500rwhp and 475rwtq