hey guys i got a 89 tII with a jdm motor with like 45k on it and i was wondering what kind of vaccume your cars pull i get like anywhere from 14 to 16. what is averave for an engine with my kind of miles?

 

I have 20"- Mazda reman with 20,000 miles if that helps.

 

Idle spec requires ignition timing to stock specs with idle speed set at stock specs - 750RPM, + or - 50RPM.

Stock - 18" to 20"
Street ported - 14" to 16"
Bridge ported - 10" to 14"


-Ted

 

my car sees like 15-20 depending on throttle position

 

We're talking about idle speeds with your foot off the gas pedal. :P


-Ted

 

Hey RETed, I pull 16 lbs at 750rpms. Timing has been set to the factory specs, and engine has 105psi compression in front rotor, and 107 in rear rotor. The entire intake track has been rebuilt and quadruple checked for leaks. Any ideas on why I dont pull 18-20lbs.

 

anywhere between 15-20 at idle with mods listed and a shitty TPS on the fritz

 

Ive found that my boost gauge isnt accurate. My gauge says 15, and my Haltech tells me 17.

 

1) There's still an intake vacuum leak.
The best way I've heard of finding those pesky tiny leaks is somehow pressurize everything after the AFM and then shooting a solution of water + dish soap.
Any tiny leaks will produce bubbles.
Most people don't go through all this hassles to track the last tiny leaks.

2) Where did you get the 105 / 107 reading?
According to Mazda, it's a bit low as the motor should be running closer to 120psi.


-Ted

 

Maz-Max did my compression test with a Mazda faxtory compression tester. Bryan, the Service Manager, who is a good guy and a Houston RX-7 Club member, did the test himself. He said that, for the miles my engine has (124K original), that is pretty good compression.

 

i only get 10 on my rebuild

 

It's pretty good compression for that mileage, but it's less than ideal if we're talking about "ideal" idle vacuum numbers.
For your compression, you idle vacuum is fine.


-Ted

 

My compression is 90-75 fresh rebuild, and its like 15-17 and a solid 19 20 when warm..