nytemarels1

I have a 347 with stock crank forged rods and forged pistons 8.5 compression.Could I use 2 Grand National turbos. What would be the pros and cons?? Or this combo just will not work.

casey38boost

iTrader: (3)

how much power do u plan on making? If you plan for anything over 600 HP u are probably going to max them out.

Also, stock GN turbo's use a 3 bolt setup as most other turbos are a typical 4 bolt.

If u already have a short block built its not that much money to up grade to twin garrett's or something better suited for the ls motor.

nytemarels1

Well 600hp for me is more than plenty for the street. I plan on driving this pretty often. If it can make that kind of reliable power than I don't want anymore.

nytemarels1

What intercooler would be best suited for this type of application ATA or ATW?

transamfreak01

iTrader: (8)

i would go with a set of upgraded turbos. it will always leave you more room to grow in the future and with those turbos ull be maxing them out and putting more stress than needed. the ata should be fine for your goals

Denali08

A/A IC for street.

nytemarels1

Thanks for your replies.

1320

iTrader: (6)

I have a twined 347 with two gn turbos. It makes 600/600 at 12.4 psi on the mustang dyno. 317 heads, z06 cam, ls6 intake, shorty headers. It will run up to the 14-17 psi range, but I didnt do that on the dyno. Probably right around 700 rw. With 3.15 gears, in 5th at 70 mph it builds boost at 2500 rpm.

Great for the budget, but its going to twin 60-1's now.....and more powwa.

BuffJoeyD

iTrader: (2)

riding in the above car is what made me want to do a twin setup ( Id do the GN turbos if it wasnt for the fact that the divided housing stuff just sounds like Waaaayy to much more fun )

nytemarels1

1320 thats awsum. I hope mine runs half is good as yours. That would be plenty for me. Tell me. The set up I have is a little different. I hope it runs good. I have like I said a stock crank, forged rods and forged 8.5 cmp pistons and twin Gn Turbos. I also have the L92 Heads with the matching intake. I had to relieve the block for the valves to clear. Comp cam set up. T56 trans and 3:79 gears. I still need stuff like injectors mass air meter etc. All in a 69 Camaro that is not finished yet but working on it. Can you think of anything else you would suggest to change and or add. Is there anything I am missing??

1320

iTrader: (6)

Its pretty muchthe same. Its a 8.5 to 1 347, with rods on a stock crank. I didnt know it was possible to get a l92 valve to clear.....or that its a good idea. Shrouding on the valve would probably hurt flow. I ve never heard of 3.79 gears...? typo? but I d run a 275/60 mt drag radial or bigger on a 69 camaro, and a 3.50 gear or lower numerically.

If you only run gn turbos or similar 60 lb injectors are what you want. If you go bigger...just go to 79's or the new 83's. No mass air meter....thats nono. speed desity.....2 bar or 3 bar depending onthe year of your pcm. Cleaner looking too with out the maf and runs better.

If your running a short tire, go to 3.25's or 3.00's.......or keep your gears and just dont use first.

casey38boost

iTrader: (3)

I will get u pics of my set up. Flipped forward 6.0L truck manifolds, twin garrett 60mm turbo's, two 46mm wastegates, blow off valve, two inlet intercooler going to a 4 inch outlet. Plenty of room in the 69 camaro, I am running a 67 Camaro.

But don't think thats all-- u still have the fuel system - tank, lines, injectors, wiring, radiator, fans, ecu reflash ETC....

it will cost a penny, but hopefully worth it in the end.

I am going to be running a stock 6.0L with upgraded patriot valvesprings, pushrods, arp rod bolts - aiming for about 600 hp until i upgrade the internals.

I will try to get some pics to day for u to give u a better idea on where stuff goes.

sixt9er

iTrader: (2)

casey38boost;
I am doing a similar project with MP T-70 twins.
I would love to see pics of a twis set-up with TRUCK manifolds in a first-gen Camaro, as I am building a 1969. Thanks.

nytemarels1

to 1320,
Yeh as far as the l92 heads fitting I shrouded the Block to get them to fit. I couldn't pass them up for the price I got the for and when I saw the massive valves and ports I had to make it work. LOL. All your replies are very much appreciated since I will need everyones suggetions. Thanks

salemetro

iTrader: (5)

Let us know what numbers you end up with. AFIK, the L92 heads lose efficiency/velocity/power on anything smaller than a 4.0 bore ( i think). For that reason, I went with a bored/stroked LQ4 (current build in progress). But you know how things can go....sometimes it's a good thing to try something different and see how it all comes together

nytemarels1

I no this is a stupid question but I have to ask. This is my first LS family engine that I have worked on. In the past I have worked the comon LT based and Big Block power plants. My stupid question is How much can you bore the 347. It is a 3.90 bore already isn't it?? The older families I no you could go as big as a .125 over bore on some blocks.

nytemarels1

1320,
I have a 86 Corvette IRS installed in my 69 Camaro. It is a Dana 36 the tallest gear I could find available was a 3:79.

1320

iTrader: (6)

Thats weird....I ve still never heard of 3.79's. I have two vettes, older ones though.

The stock gears are ussually 2.59's or 3.07s I think. A quick search found this thread on corvette forums...talking about everything from 2.59's to 3.73's.

http://forums.corvetteforum.com/c4-t...-the-same.html

Sounds like neat car. As far as I know, I ve heard .010 yes .010 is the safe limit of the 346. I have only ever honed them and built 347's out of them. 3.898 to 3.905.....

6.0s are going to the .070 ls3 piston in a lot of cases but I dont think thats garanteed. I sonic checked one of my 6.0 strokers going .055 over. All was good, and it looks likeit would handle .070 over as well.
But thats the iron block...

casey38boost

iTrader: (3)

Here are some pictures of my 67 Twin Turbo setup so far:


twin 60mm garrett turbo's, 2 jgs 44mm wastegates, air to air intercooler with two 2.5 inch in to a 4 inch out.

will be adding dual 3 inch downpipes and edelbrock pro flo manifold soon.


more pictures here":

http://s298.photobucket.com/albums/m...t/67%20Camaro/

nytemarels1

1320 Yeh your probably right with3:73 rear gears. I don't no why 3:79 stuck out in my head. Thanks for the reply.