germeezy1

I would in an F-body but not in a C5. I wonder what a 40k mile LS1 is worth?

obZidian

iTrader: (2)

even so, what is the difference between an aluminum and the iron? 85ish lbs.?

obZidian

iTrader: (2)

question, what kind of motor do you have already or are you planning of building one in the future?

I ask, because, thoough it would be better to pick the rwhp first, then the motor after the turbo has been selected, its almost like working backwards. We have the motor already, now what can we an we do with it now...

Initially, i spent the majority of the build period, probably six or so TRUE months, trying to figure a course of attack with my 408ci. I had it already for n/a and wanted to build a boost app. with it. Get comfortable with compression maps and flow per CI tables, they are your friends!!

Now, depending on your current or future CI motor, pick the turbo appropriate for that motor. If its a 346ci, than you some choices that will dictate how that turbo will scoot! A t67 with a .86 ar will boost early but not provide a nice peak number. Now, a t76 on a .96, will boost a bit later but have some head room. That A/R will tell ya how fast that turbo will boost. Same turbo, one with a .86a/r and the other with a 1.01a/r... the .86 will boost faster but die early as the 1.01 will only begin to get started.

get it. It not just get a turbo and see what hapens. NOW, on a 408ci... i wouldn't want to run anything t4 flange. IF ANYTHING, its gotta be a t88 or more. Im running a s85 t6 with my 408ci, so we will see how this combo works out.

Now, on topic, i will say, that this all really has to do with HOW MUCH CASH YOUR ARE WILLING TO SPEND ON THE PROJECT AND WHY. You can have the money, but if you are a purist and have a slogan that you CAN do more with less and prove it... then go ahead. You can build a 346 with the proper turbo to make snot more than a 408 FI. However, a 408ci with the proper turbo, AND with the added cost of proper equipment that you will now need to support that motor, turbo, power application.... can also be built to make a **** load more than a 346.

IT all depends on which route you choose and how you want to show-off your FI skills!!! The larger cube will cost more becuase the supporting mods at that level are more expensive. Its that simple.

LTLHOMER

iTrader: (10)

lol are you going to build one of these???

Country Boy

iTrader: (24)

Also remember that a bigger motor needs more air, IE. bigger turbo or headunit which also means more $$$$. Its all about the mighty dollar.

VINCE

iTrader: (1)

I know for my car the 408ci works flawlessly. I have yet to turn up the boost. The only individuals that know the limits of the TTi X kit that I have are the builders of the kit. So far no one has pushed my current kit to its limits. I was told that my kit was designed for the 346ci to the 40Xci combo. Now there is a turbo option for the 4XXci guys, but with the C5 drivetrain limitations going crazy on the boost could be costly. Please dont ask me what size turbo's are on my car because I honestly do not know. I just know they work well for my application..

nick y

iTrader: (1)

ah vince you can never have enough!
427 with 225 TEA trick flows with turbonetics 66mm with their new gt style turbine wheel would do the trick .

VINCE

iTrader: (1)

I think so as well, but these guys are saying the only advantage of big cubes is for a street car if the turbos are equal..

Basically a 346ci with the same combo you mentioned above can make the same peak power as a 427ci with the same turbo combo. The only difference will be low and mid range power, but once you are deep into boost the MAX power output would be similar.

So in a hypothetical race the 4XXci car would jump out several cars and then the 346ci would stop it's forward motion after that and they would actually be accellerating about the same speed..

LTLHOMER

iTrader: (10)

I've never left off idle when racing though???

VINCE

iTrader: (1)

I am sure

nick y

iTrader: (1)

MAYBE BUILD ONE AND FIND OUT?

LTLHOMER

iTrader: (10)

Closest I got to idle was 2800 rpm's and 1.5-2 lbs of boost. Still went a 1.45 and it'd do that on the street or strip. Gets up on the brake fast if you know what you're doing (or in our case just know someone that knows).

I can't even imagine how fast I would have gone if I had a 408!!!

obZidian

iTrader: (2)

thats with the same turbos..

now match a set of turbo's to the 427ci and the end result will not be the same. The peak, mid-range of a 427 with flow matched turbo would step all over the 346 since it has more potential of power productivity than the 346ci.

Theoretically, a well matched 346ci makes, let say 400hp n/a. At 15psi, hypothetically, at 100% efficiency... it should generate 800hp. Well, a 427 in similar prep form is gonna make more n/a, let say 500 n/a or 450 n/a for the nah sayers! Thus, at the same 15psi, 100% efficiency... that package should atleast 900-1000hp, with a different set of turbos and exhuast that match the 427.

Rickys S/C Z28

iTrader: (13)

thanks yall anyone you would go with????? im running a procharger FYI

germeezy1

Well since I am not as rich as some of you guys it almost sounds like a forged 346 or 370 is the way to go. And my damn tranny is only rated to 550-600 RWHP....so it sounds like a 346 with FI will have no problem getting me there.

LTLHOMER

iTrader: (10)

All the guys with 400+ motors are telling you that 400+ motors are better but so far in this thread all the 347's run faster. lol

obZidian

iTrader: (2)

thats because the 400ci+'s are so fast, that they dont even get a chance to race in a class, there isn't one available yet!

Basically, it all depends on how you maximize what you already have, i think LTLHOMER knows this and KP knows this very well. There are 4 bangers running in the 7 O's, and the funny car guys are running monster BB.. its all relative to what you have and how far you can take that. You want to do it with less, than go ahead..

Me, i already had the 408ci.... so i used that and made a FI package with it in mind.

engineermike

I've been preaching that smaller displacement will ultimately make more max power with most people's turbos, but I just stroked up to 388 cid because my goals were max power at low boost.

Mike

LTLHOMER

iTrader: (10)

Funny cars/top fuel run 500 inch motors. Not exactly a monster only about 90 cubes more than those 408's. Oh and 7000+ more hp.

LTLHOMER

iTrader: (10)

I understand completely. I am just having some fun with the thread because it's pretty much pointless at this point. Anything can be made to work but there is only one 'cheapest' route and I doubt cheapest involves anything more than a 347 for something that is going to run in bottom 8's and slower.