Mine will prob be on a trailer home lol

I'm also concidering twin 66s from what a friend is telling me it. An be super gnarly and support 1500 for about the same price

Packaging is the issue with corvettes. There is very little room in the front. Turbos are much more adjustable for any given situation. Expect it to cost a bit more than a blower setup by the time it is all said and done. It comes out close to the same if you factor in the cost of headers and full exhaust with the blower setup. That is easily $2500-$3500 for a vette if you buy nice stuff.

yeah this is true i also decided im going with a 444 lsX over the Ls2 its gona cost a pretty penny but it will happen. the 66's will be a fender kit. im thinking strongly of the twins now because there is now a F1X silver C6 that lives with in like 30min of me back home.

... Stop going bigger lol

im going to eventually if i go twin 66's they will prolly be junked in the future and be bigger. me and the 3-4 other guys im building this with are planing acoupple trips for 2015 that include the vette and acouple 1700+hp cobras.

Well lol I could forge up the lq4 and hur 1k no but not next year lol . 650-700 should hold me.for a while lol. Unless I want to go faster than 10 flat

Here is the thing with FI. The bigger you go on the engine the bigger you HAVE to go on everything else. 66's will choke on a 440" motor. That means you have to go bigger. That means you need more fuel. Bigger lines pumps and injectors. You will need 6 bolt heads to hold that much pressure. Bigger waste gate, bigger bov, better intake manifold and tb. Then you get to the driveline. Even in a light car no one builds a t56 that will hold up past 1200whp. 1000whp is on borrowed time as it is. You will get tired of popping $4,000 transmissions.


There are 3 FI breakpoints that I try to explain to people taking the FI plunge.

1: keep it under 750whp on a turbo setup or 650whp on a supercharger setup. At this level most all of your stock parts can be used reliably.

2: 800-1000whp and reliable will mean a forged bottom end in whatever block you choose. Ported or aftermarket 4 bolt heads, all new fuel system, built driveline, etc. This is going to cost you double what setup 1 will cost. You have to make the decision between 700whp or 900whp for double the money.


3: 1200whp+ You will need the race version of every part available. Billet this, 6 bolt that. Built automatic or a black card. The chassis needs addressing along with serious safety precautions. This can easily be triple setup one or double setup 2 for 1500whp+.



Its not a linear progression of cost. If graphed it would look more like a set of steps.


So with that in mind an ERL prepped 6 bolt LS2 block with a solid bottom end and 6 bolt heads will live up to 1500whp reliably. 1200whp would be its wheelhouse. I would leave it stock stroke. Taller compression height on the pistons for a thicker ringland and more support for the piston in the bottom of the bore preventing rocking which leads to oil consumption and premature piston wear. An FI engine has a completely different set of needs than an N/A or nitrous engine. Strength and beef (heat tolerance) take precedent.


It's not much different than your cobra. Strap on a 2.6 and make 650whp or spend double to make 750-800whp.



EDIT: as an example my 1000whp build straddles 2 and 3. The engine is built for 2 and everything else will be built for 3. When the engine goes I drop in something stronger and go real big.


Doing everything myself except the piping fab I will have $20k in it just in parts. Lots of these things are more expensive for a vette.

This post was edited by FMX_89 on Oct 8 2013 03:51pm

I understand the points you are making and all very good points but the 444 and the 66s just because it cab turn 1500 I'm still only going for around 1100 or so. Allthough no corners will be cut during this build so Im fully expecting for this to cost a right nut and a arm lol

I should have explained that point a little further.


When the turbo(s) is undersized for the engine power will fall off early. If you want it to pull to your desired shift points based on your gearing you HAVE to size the turbo correctly. The only thing you can do then is turn the boost down to keep it at the power level you want. If you do that then you really could have went with a lesser setup altogether unless you plan on making more power later.

You can have your 1100whp on a 440ci motor with 6 bolt heads that flow 350CFM but it will likely be at 5500rpm. After that it will flatline and your backpressure will double or triple by your rev limit. That causes ridiculous amounts of heat because the turbo is trying to overspin it's efficient range in the compressor map. It's a trickle down effect.

With a procharger setup unless you fab up a wastegate on the intake charge pipe you cannot control boost on the fly. It is based on pulley size just like your Cobra was. At max impeller RPM it will only flow so much air. The curve will look better than an undersized turbo setup. The only problem you will run in to is blower life at max RPM and the heat caused by that RPM.


Suffice to say if you are going to undersize a setup both will give you high IAT's and low efficiency but the turbo engine will actually fall on it's face. The supercharged engine won't.


My suggestion would be 72's if you are really considering twins and a 440ci setup. Honestly though, that many cubes isn't necessary until you start getting into outlaw drag radial type of power. It actually makes it harder to choose the proper turbos for the job. You are better off with slightly less cubes (and backpressure) with a higher pressure ratio (boost) from an efficiency standpoint. The outlaw guys are running 422-45xci engines and twin 80-91's. By using the same size engine and much smaller turbos you are effectively limiting your available RPM. You will have a low RPM stump puller type curve and your gearing would have to reflect that. If it is a highway car that is not what you want. If you are trying to build it to run the number at the track too you will want to see what gear and RPM you need to cross the stripe in the right gear at a given mph. 1100whp in that vette should be in the 160's.

One of the most successful street cars in existence ran a stock cube ERL prepped 6 bolt LS2 block with out of the box heads and a single T4 GT91. It made ~1400whp and ran 8.50's@168mph weighing 3800lbs. You can build a 1500whp combo with off the shelf parts and nothing fancy. If you want to have room to grow in the future invest in an RHS or Dart aluminum block. The LSX is strong but it has quality issues and weighs 150lbs more than the other two. That really becomes a big deal in a corvette. Along with the turbos, piping, and intercooler you are sitting Erik Berg on your front bumper. If you want to dump money that is a good investment because those blocks can hold all you can throw at them and be used for build after build if you wanted to grow.


My 1500whp reliable engine would look like this:

Kurt Urban or Shawn Miller built RHS block 427 or possibly 408. With a 4.125" bore that is a 4" or 3.825" stroke.

Callies Dragonslayer crank
Callies Ultra I beam rods
coated Weisco or JE pistons
Dowel pin mains
Billet main caps
ARP main studs
1/2" ARP 2000 head studs (6 bolt setup)
6 bolt Trick Flow 245's with Jessel rockers OR 6 bolt Mast LS7 based heads with Jessel rockers


Truthfully any 6 bolt head will allow you to make 1500whp pretty easy at 25-28psi.


The BIG boy setup

Same block
Bryant Center Counter Weighted crank in 4" (427)
GRP Aluminum rods
Custom coated CP pistons
Studded and girdled mains
billet main caps
ARP main studs
1/2 ARP 625 custom aged head studs
MAST MOZEZ heads with Jessel rockers

That one is more or less what the outlaw radial guys are making 2500hp with at 35-38lbs of boost from twin 88's. It's also a $35k engine all said and done.

This post was edited by FMX_89 on Oct 8 2013 05:00pm