How much boost is too much?

[CorvairKid]

Hey everyone I was wondering how much boost a corvair motor could withstand. Been building turbo corvair for the past year now and still little new to it with corvair motors. Wondering how much people have ran boost up to on modified corvair motors?

[miniman82]

Define 'modified'?

The stock rotating parts are pretty tough, use forged pistons and there's really no reason why you can't push 20 PSI through it. When I first got my 180 engine, it was completely stock. On a cold day, I could get it up to 11-12 PSI. I rebuilt it with an Isky turbo cam and ported heads, which didn't really get me any more boost but it did make better use of the pressure being more efficient from the head flow. After the body work is done, I plan to install the E-flow and 45 DCOE Weber carb. I will run it at 15 PSI with water injection, hopefully it will live.

[CorvairKid]

I have forged pistons, the valve seats have been deep seated, TB-30 cam, high rev lifters, roller rockers, and heavy duty springs. I do have full finned cylinders also. On top im running water/methane injection and intercooler. Its a blow thru turbo system using T3/T4 turbo charger and 750 cfm DFI throttle body. Right now im only at 11 psi. Gets there very fast but i think i could adjust waste gate to allow more.

[flat6_musik]

I would say the only thing limiting you is the stock rods, but if they can live under the factory 11-12 psi, I don't see why 20 psi isn't do-able with your forged pistons.

[CorvairKid]

where can you find some forged rods? cause that was one thing that i was worried about when increasing boost

[flat6_musik]

http://www.corvairspecialties.com/conrods.html

[CorvairKid]

Thanks i will have to get a set once the snow starts falling and i put car away for storage

[CorvairKid]

i also have to find 3 bar map sensor. 2 bar only lets me go up to 15 psi

[Scott V]

where can you find some forged rods? cause that was one thing that i was worried about when increasing boost

all stock vair rods are forged. they are plenty strong for the boost you are going to run. get a set rebuilt by a good shop & have them lightened & balanced. they will be lighter than the china made rods & plenty strong.

-Scott V.

[65Ragtop]

The rods in the link above are fine rods but Scott V. is correct about the stock rods being forged and plenty strong. Unless you NEED to go to some new rods, the stock ones prepped properly should work fine. If you are going for some serious boost I would be more inclined to put my $ in a set of HP ARP case studs and a set of stonger super duty head studs. If you start pumping serious boost these will help hold things together and keep them from moving around. The full fin cylinders were a good addition as the stockers are a bit thin if bored out for a good turbo app. I will presume you are running a hardened crank. I will also presume that with your TBI you are running a good hot spark that can handle the boost as well. You seem to have a lot of the other bases covered already. Good luck.

[CorvairKid]

Yes i already have the new studs on the rods and the heavy duty head studs already. It seems like everything should hold up for the extra boost. I have unhooked waste gate and let turbo spool up a bit and it put out well over 25+ psi. Im not going to go that high but just did some trial runs to see what it could produce. Its pretty nice having 60 degree weather during christmas lol usually we have 3 to 4 feet of snow on ground

[65Ragtop]

I hear ya on the weather, it was in the 70's today here in AZ. T shirt n jeans weather! I saw your car in Denver.....right? Sweet machine. Now where the heck did that 9/16th socket go..........

[CorvairKid]

My car was there but i met so many people there cant remember if i saw you. 9/16th socket???

[65Ragtop]

" 9/16th socket ???" Sorry.... talkin' to myself. Trying to work a little on the car and do my end of the year chores all at once. Was looking for my socket when I sat down to chime in here for a break from it all.

You probably wouldn't remember me, you were indeed talking to about 5 people when I walked up to look and listen for a minute. I had my 2 young boys with me and they kept me moving through the cars and crowd. Anyway, sounds like you have a good setup and you seem to know what you are doing. Good luck and keep us posted on your progress. I might build another turbo engine one of these days. Always good to see what others are doing.

[CorvairKid]

Oh ya its always nice to see what other people dream up and bring to the shows. Right now we are making new fuel injection kit that uses stock carbs and we turn them into throttle bodies. So they bolt right back up and use original air cleaners and everything. For people that want to keep the stock looking motor but have some performance form the 21st century.

[65Ragtop]

I really like your idea if you can get it to work. Seems like just the ticket a lot of 'vair owners might be looking for. Can't wait to see it.