Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: Twister2gt on May 09, 2017, 11:13:51 AM

Title: Blow thru carb turbo
Post by: Twister2gt on May 09, 2017, 11:13:51 AM
Been throwing the idea around of converting to carb and doing a blow thru turbo setup on it. This may be the wrong forum to ask but was wondering if anybody here has had some experience with anything like this. I know we have cast pistons but i think i will be okay if i keep it under 10psi. Just got done with the HO swap on my 87 cougar. Will a 255lph efi pump work right if i plumb a larger return and add a bypass regulator with boost reference. Was going to run a msd btm for ignition.  I was looking at those on3 turbo kits or building my own kit.
Title: Blow thru carb turbo
Post by: rotorr22 on June 06, 2017, 12:05:59 AM
Quote from: Twister2gt;460680
Been throwing the idea around of converting to carb and doing a blow thru turbo setup on it. This may be the wrong forum to ask but was wondering if anybody here has had some experience with anything like this. I know we have cast pistons but i think i will be okay if i keep it under 10psi. Just got done with the HO swap on my 87 cougar. Will a 255lph efi pump work right if i plumb a larger return and add a bypass regulator with boost reference. Was going to run a msd btm for ignition.  I was looking at those on3 turbo kits or building my own kit.

I blow thru a carb on my 509 BBC boat with an M3SC ProCharger. It can work well if you purchase a carb from a company experienced in building blow thru carbs. I use a Holley 1000 CFM DP built for blow thru operation by CSU in CA. They can provide a carb specifically designed for your application and have lots of experience with blow thru set ups. The engine will have to be tuned in much the way as a multiport injected engine and will have to have similar fuel and ignition system upgrades as well.

Cast pistons are a risky proposition. Modern Hypereutectic cast pistons are actually pretty strong and provide excellent noise and oil control  but can shatter if subjected to moderate detonation. You can detonate a naturally aspirated engine with a bad fuel, too much timing or just a bad tune up. Adding a power adder just increases the risk. I personally would build a forged piston short block for any blown application. I don't care how low the boost is. Consider MLS head gaskets a must have as well.