I bought a '65 Corvair where I'm going to convert it to a LS4/porsche 996 trans. I've already got a guy working on the adapter and the trans is enroute to his shop, so this isn't just another what if posting. I went with the LS4 because of cost vs. the LS1. And the 996 trans was about a grand cheaper than the G50, cable shift, and 6 speed. Will be a mostly daily driver.

Ok so stock is 303hp. I've seen a lot of mod's on this site but they're all for stock fwd impala's. So with that said....what can I do to max out this engine and how much HP do you think I can get it up to without a supercharger? Which cam would you recommend? Which injectors, intake, TB, tune, DOD delete? Think of this as your dream build just shy of a supercharger/turbos. Do you think I could get it up to 400hp?

 

http://www.trickflow.com/partdetail....5&autoview=sku

Trick flow dyno chart. http://static.trickflow.com/global/i...05-455-425.pdf This is with a truck intake and tb.

Add a LS7 lifters, LS2 lifter buckets, LS2 valley tray, LS6 intake manifold, custom headers w/3" exhaust. 3800 stall with good gears and the LS4 will rip 475 flywheel hp easy! Use 28-30lb injectors.

If you want even more power then use the .045" head gasket=11:1 and this cam http://www.trickflow.com/partdetail....2&autoview=sku
496 fly hp. I posted this build awhile ago. The engine had a electric water pump and long tube headers.

We have 4.8L flat top pistons so with a .045 head gasket and 58cc heads you will be around 11.1 Cr the cam I listed up above perfect for a street strip engine. Plus your car is much lighter then the W-body's. I am 3965 race weight.

 

Yeah, thats the kind of gravy I'm talking about.

Well to start the trans is a manual, and those heads you posted are for the truck motor, though I see where you're going with that. I can use some Vette shorty headers easy.

I saw on the FAST injector page that 58 psi is the stock pressure. Higher pressure usually means better fuel atomization. Can the system handle higher pressures and can a factory ECM reprogram handle it (or the injectors)? Though I realize that's pretty high anyhow. Just a thought.

Not sure if I'm ready to dump money into heads. What I understand the LS4 (LS6) heads flow pretty good. Whats special about the LS7 lifters, buckets and the LS2 Valley tray? I"ll search for that build or do you have a link?

 

The heads posted above will work with the LS4.

You can send your heads to advanced inductions for cnc porting and custom valve grinding. Total cost is about 1200 IIRC. They have a street port that has a intake runner
vol. of 219cc vs 212 stock LS6. I would avoid anything above 220cc for a street 5.3L.
The 205cc head form Trick flow flows simular numbers to bigger heads with a smaller port. Port Velocity is the key for throttle response.

I would stick with a cam in the 218-222 range for the intake lobe and 220-224 for the exhaust. Valve lifts can go up to .590 or more with ease. Lobe seperation in the 114-116 should work with a manual trans.
If you want to get super crazy then contact Patrick G. He will build a cam to taylor your engines needs. Price is 425.00 and 25.00 is credited back to you if you order through EPS.

You can search Adavanced inductions and Patrick G in the search field.
I would stick with a LS6 intake. I have a ported intake from Bare Essential Racing. The guy who runs the show is Cajun. He is the man! Intake w/porting is around 425-450 shipped. He can even do powder coating for a small fee.

If I could go back, I would use the Trick flow heads and the stage 2 cam I posted above. By doing this I could have sold my LS6 heads, and would saved money on the valve train. The top end package is about 2800 through Summit and comes complete with timing chain (not really needed) camshaft, head gaskets, head bolts, balancer bolt, rockers, pushrods, and heads.
Can't build a cheaper kit then that!

If you really want to get super low buck... then install a LS6 cam, LS6 intake, and Mill or, use a thinner head gasket to achive 10.5:1 or higher CR. I would advance the cam 2-4* . and use some PAC springs with Titanium retainers since you'll be shifting above 6500rpm. The LS6 cam is a dog in heavy acrs with automatics. Since your going with a manual and your car is light this cam should work great. Good luck and post some pics of your build!

 

I won't speculate to the HP potential, but it should be quite a bit more than stock. Here are the specs for my LS4/manual 6 speed build that is underway:

85mm MAF
LS2 90mm thottlebody
LS2 intake, fuel rail and injectors
Stock LS4 heads
Katech rod bolts
224/230 DoD camshaft w/ springs and pushrods
12 lb custom aluminum flywheel
LS7 exhaust manifolds with total exhaust length under 6 feet

Mounted transverse in the back of a fiero. Target weight 2850 lbs. Once it is running phase 2 will probably be having the heads milled/CNC ported.

Build thread is here:
http://www.fiero.nl/forum/Forum3/HTML/000123.html

 

David- Whoa, uh, you've done your homework huh? Well when I eventually get out of Afghanistan, I'll be excited to build this motor. Just one....more...contract.

Guru- Hey, I have have a lot of your pictures from that build saved as reference. I've gone through that thread several times. Being over here gives me lots of time to research and brain storm. In fact I've got Eric at A&E machine doing my adapter. I seriously considered getting a Fiero, but in the end I liked having a back seat for passengers. The corvair is so much lighter than your regular muscle car. It's like the best of both worlds. Also I didn't go with the Fiero because of smog in CA. Trying to get an aftermarket engine approved can be a real PAIN. Again, one more year of this contracting and I'm done over here.

 

So after some more research I've found a few things. Note: '65 corvair, stock engine location.

Is this correct: Because I'm putting this in a manual trans car, the stock ecm won't like the fact that there's no auto trans. So would need to end up using an LS1 ECM from a manual trans car? This in turn would get rid of the DOD? I don't have my heart set on the DOD.

Intakes: In trying to find budgetable alternatives, The LQ9 intake seems like a good alternative. It will fit under the deck lid and can get it a heck of a lot cheaper with rails, injectors, and TB than an LS6 No, it doesn't flow as much as the LS6 intake, but heck....a 6.0L intake on a 5.3L, I think it will be alright. Yes the intake is ugly but I have a pic of one that was cleaned up and looks pretty nice actually.

LQ9 injectors: Appear to flow less than LS4 injectors....weird. One search revealed 24 lbs/hr. From what I gather, the injectors will cross over but nothing for sure yet.
Anyone have any more solid info on this? thanks

 

In the LS4 tune, there is switch you can set for manual transmission. I do not know if it will work yet, but it is my first plan of attack. If that doesn't work, then just turn off all the transmission codes and then it should work (but DoD might still not work), but would probably need some tweaking for throttle transitions.

 

when are you getting that thing finished? You've been working on it for ....a year?

 

Actually about 1.5 years... but who's counting. Hopefully by November it will be running.
Spent the last 2-3 months distracted doing a 383 SBC/Getrag swap in another fiero... but it is nearing completion now.