Turbo

[Cbitz233]

Curious about if anyone here has put a turbo on the 305 in an avanti. If so how? I was thinking i could fit one where my a6 compressor was but not sure if a nice turbo manifold would fit without modification. 

[studegary]

I know that superchargers have been fitted to the Chevrolet V8 in Avantis, but can not recall any turbocharger applications. 

[Footer]

My 83, RQB 3771, is on Bob Johnson’s registry with some very interesting pictures of it’s early life, including a supercharger on the 305. Wish I knew more about it’s history. Lots of changes over its life. No more supercharger, no more wire wheels, moonroof, luggage rack or red dash. Dan Booth said there was no build sheet available for it. A turbo would be novel but you wonder if you would get a better bang for your buck with a crate engine.   Mike

Edited December 4, 2018 by Footer
Additional info

[Cbitz233]

Without a doubt i would with a crate engine but i just wanna make a little street machine. Gonna build the top end, turbo it and change the gearing. 

 

[Gunslinger]

Look at Summit Racing's website or Edelbrock's...they usually have supercharger kits available for the small block Chebbie...maybe even available as a kit with crate engines.  Your problem is not finding a kit that's compatible with your engine but the problems associated with fitting it under the Avanti hood without a lot of modifications.  It can be done...it will take a lot of careful measuring and planning...there are always unexpected issues.

I would also consider (since you want a street machine) adding a Tremec 5-speed transmission.  A 6-speed might be even better that would definitely require modifying the transmission tunnel some.  I would also change the exhaust system from 2" pipes to 2 1/2" to let that little monster breathe.  

[Cbitz233]

Gunslinger i just put on hedman hedders block huggers, 2 1/2" in pipe and then flowmasters and welded on the original tips. It sounds so much better and pretty sure the 0 to 60 picked up a little better but not much. Sadly... the test drive after the exhaust was put on, my trans pooped out on me and pretty sure I lost 3rd gear. Found some turbo kits with nice manifolds and think i can make it fit where the a6 compressor used to be with a little shaving of the bracket. But gonna have to wait till i replace the trans to even think about it

Edited December 9, 2018 by Cbitz233

[Gunslinger]

The basic issue is common to pretty all engines from that era...they're set up for low emissions than performance.  The 305 is no exception.  To really wake it up will take head work, a camshaft change and a better intake.  It all depends on how much performance you want...and how much you want to afford.  If that's what you want a crate engine at the power level you want is probably the most cost effective way.  For a blower, you would probably need an engine with a compression ratio no higher than about 9:1 whether it's your own engine or a crate engine.