First I would like to say the 2nd gen cars are soooooo much nicer than the first, I love my 1rst gen too but wow.


Ok anyway, I got the car in perfect shape. Boday is great but the back pice where the guy said he was rearended, but its a verry small spot. When he got rear ended the other persons car hit the tail pipe forcing it foward and breaking it at the cat. (do thies cars have 2? if so going from the back of the car -> its the first cat under the car) will this break cause a loss in power? due to is not having any back pressure(due this motors even need back pressure?) Im going to do a complete 60k tune in a day or so to see if i get any gains from that. the car has 148k miles but still has 95 comp on both rotors. anyhow i just wanted to know about the break and if it has any effect on the HP. i dunno just seems kinda slugish.

 

First your mutiple bumps have been deleted. Bumps are forbidden here in the 2nd gen RX-7 technical section.

#2 no cars need back pressure.
#3 you didn't say what model and year. Depending on year, a exhaust leak in the wrong spot (you were not very clear where/want the problem is) will cause reduced power.

 

I didnt say what model correct sir, but the title says 86. Its a 86 GXL. and the exhast has a massive hole after the cat. any bigger and the back half of teh exhast will fall off.

I have searched and half of the people say it need back pressure for 2 ports to open, others say no it odesnt.

 

You need exhaust volocity for the aux ports to open... they may not be opening if you indeed have a massive hole after the cat.

Back pressure = bad
Forward pressure = good (and needed for a 86-88 non turbo to open the aux ports).