Join Date: Jun 2006
Location: Los Alamitos, CA
supercoupe exhaust backpressure q's- how do I fix it?
Hi there, I just bought a 1990 Supercoupe 5-speed, kind of high mileage.
From what I understand, it appears that the stock SuperCoupe exhaust is extremely restrictive and the 15psi of backpressure it creates can cause headgasket failure.
My SC has 187 or 189k, I can't remember which, miles on it and it runs very smoothly, and feels quite strong. I've been babying it, as did the previous owner and have been shifting at 3k in an effort to make sure the headgaskets don't fail.
Since I am on a limited budget and since I have to go to Pick-Your-Part anyways, I want to know if I can't put the V8's duals on as a means by which to reduce backpressure while still remaining smog legal.
One, are the v8's duals usable cat-back on a 3.8SC?
Two, if the V8's duals are unusable, what is another cost-effective solution to the backpressure problem?
Three, are there any other junkyardable inexpensive items that can be added to extend engine life and promote reliability/durability?
Thanks very much!
96 Laser Red 4.6L - Custom
Custom Nascar-Inspired Bodykit - 55* Rear Spoiler - J-modded Trans - 80mm MAF - One-Off Diablosport Chipmaster Revolution Chip/Tune W/Toggle - ScanGaugeII Diagnostics & Data Readout - PBR Brakes - Drilled/Slotted Rotors - SC Wheels & Springs - Falken Tires - KYB GR-1 Shocks/Struts - FSTB - RSTB - RTLB - LECB - 60/40 Split Rear - SC Seats - SC Vac/Boost Gauge