Exhaust on an MK3 Supra

[spainobain1234]

Here it is, I just purchased my first 1987 7mgte Toyota supra Automatic, Overhauled turbo, performance long block installed, 3 inch tanable down-pipe , AND 3 inch elbow, I just passed my last year of emissions, And decided to completely remove my exhaust from the 3" elbow pipe back. I connected a 2.5" exhaust straight pipe to the 3" elbow, and ran the flow-master straight pipe to the back with a flow-master muffler. IT smells strong, and I hope I am not messing up the engine in anyway.

Question, can this exhaust straight pipe and single muffler cause horrible back pressure and can it cause damage to my engine, or possibly mess with the air/fuel ratio? I have stock MAF, stock air-filter box, and 3" going to 2.5" exhaust.

Upon starting up my supra everyday to warm up, there is a bit of clanking going on during idle. It is a single clank every like 10 seconds, but sounds like a stalling noise, even though the idle rpms remain constant and healthy. Could this be a knock? Piston slap? timing? possible bigger cam in the performance long block that was installed? The person I bought it from gave me the reciept of the performance long block 5800$. So This clank sound might be normal?!??? Thank you Very much!
Ben

 

[Poodles]

Exhaust, no, you're not hurting it, but you'd get more performance out of a 3" system. Plus, if you're ever cruising with someone, they'd enjoy you having a cat so their eyes aren't burning when they're behind you...

Sound from the motor, can't say. Sounds like the typical supra hickup, but can't be sure.

 

[spainobain1234]

Also, the 7mgte is boosting around 10 psi, but I only have a stock air filter. I need kN intake, a lexus airflow meter, 550 cc injectors, and a TUNE, and a boost controller, a bunch of stuff that comes in the GT35r trubo kit on ebay. is it okay that I am boosting 9 psi with a stock air filter?

 

[laxboy36]

get the blitz cat back exhaust. that all cats off.

 

[Backlash2032]

Do NOT get a k&n oiled filter. They WILL kill your AFM with a quickness. Get an AEM Dryflo or equivalent.

Sent from my HTC Rezound using Tapatalk 2

 

[supra34]

I would go back to a full 3in and buy a dryflow filter intake kit. As for noise its prob not any piston or rod knock those are pretty much a constant knock. It could be that muffler getting hot and making that weird ticking noise you know after you run a car hard for awhile and then stop and shut it off it makes that ticking knocking sound that might be it but not sure without actually hearing it

 

[Backlash2032]

You really need to post up a video for us to diagnose noises..

And FWIW, my 7M would hesitate for a split second off idle if you blipped the throttle really quickly, and that hesitation and subsequent drop in oil pressure allowed the valves to click for just a second... Or maybe it was just the lack of noise that made it more apparent lol