Hi Flow Cats and restrictiveness
Hi Flow Cats and restrictiveness Hi,
Just wanted to let everyone know my experience with hi flow cats on my H/C/I D1SC 346 ls1. Heres the link to the whole process if anyone cares to take a look.
https://ls1tech.com/forums/showthrea...1873551&page=1
Long story short, I dynoed the car with 4.5" pulley and it made 601/515 on the dyno with 10-11psi. Couldnt figure out why it was making so much boost. Bob mentioned the kooks hi flow cat cats may have been clogged up. I took them off and inspected them but they werent clogged however the casing was cracked, i presume from the increased exhaust pressures. So, i ordered a new TSP Y pipe with no cats and took the car out for a spin with the hp tuners data logger. I took it up WOT a couple runs and it was still fast as hell but pulled 4.5 psi @6500. This was the only change done to the car. I knew high flows were still restrictive from looking at the inside but i didnt think they were that restrictive! So i lost 5.5 psi just taking the high flow cats off!! It just proves the theory that forced induction motors DO NOT like restrictions!!!
Just wanted to let everyone know my experience with hi flow cats on my H/C/I D1SC 346 ls1. Heres the link to the whole process if anyone cares to take a look.
https://ls1tech.com/forums/showthrea...1873551&page=1
Long story short, I dynoed the car with 4.5" pulley and it made 601/515 on the dyno with 10-11psi. Couldnt figure out why it was making so much boost. Bob mentioned the kooks hi flow cat cats may have been clogged up. I took them off and inspected them but they werent clogged however the casing was cracked, i presume from the increased exhaust pressures. So, i ordered a new TSP Y pipe with no cats and took the car out for a spin with the hp tuners data logger. I took it up WOT a couple runs and it was still fast as hell but pulled 4.5 psi @6500. This was the only change done to the car. I knew high flows were still restrictive from looking at the inside but i didnt think they were that restrictive! So i lost 5.5 psi just taking the high flow cats off!! It just proves the theory that forced induction motors DO NOT like restrictions!!!
I really don't see high flow cats being THAT restrictive if they are good working order. Still pretty crazy. Although if you were making 10psi and lost 5 psi you are at 5psi now? Crank that **** up!!!!
Yeaaaaa 5 psi? At over 600 with that setup sounds right. I bet your belt is slipping or you miss read your gauge. For what it's worth when i ditched my cats I couldn't tell a psi difference. Or a noticeable power increase. It does sound better though.
Its reading right off the 2 bar map, I know its right. Have you looked at the "high flows" they are very restrictive.
I won't argue that high flows can create a restriction. That level of restriction though? Questionable. And making 600+ on 5psi would be insanity. Either way I'm glad your ride is working well and hauling ***
