ok i bought another rx7 a week or so ago and thought it felt a bit sluggish. My previous rex was pretty much stock other than a (cone filter, and straightpipe to a turbo muffler. it's an 86 base, i have no power stearing, a/c, no air pump and no vac rack) This car was quik it would take mildly built gsr's and the like. but the body was junk. i came across this other 86 only this ones a gxl but it has all the power stearing and junk. i removed the ac belt and the air pump, and it has the unorthedox racing unjderdrive pully, hks mushroom filter, and some one got rid of the original catback by welding two 2 1/2 inch pipes the the back of the main cat. it's odd, my old rx7 smoked the new one while the ports were wired shut, and the ports were opening in the new one. . oddd. . anyways to the dyno. i dyno'd the new one today and i got 126 @ 6200 for hp, and 120 @ 4550 tq. How does that sound for the mods i have? i think the motor is weak. . . should i be pushing more thatn that? I could really use some input guys, i need to know if i should rebuild and port or not. just htought i'd share the results.
thanks Dom and please any info would be great. What does a stock rex Dyno at?

 

oh i know the stock power is like 146, but does anyone know what it is at the wheels? thanks

 

126 at the wheels sounds resonable to me, anyone else?

 

yea i'd like some more input, anything to contribute would be great. i'm gonna go back in two weeks or some when i finish installing a s5 upper intake, throttle body with mod, rb collected header and 2 1/2 inch sigle exhaust, removed power stearing and a/c. hopfully i will gain some. but still 126 sounds kinda low or maybe i'm just over estimating the underdrive pully's and efan and junk. thanks though. keep the responses commming. thanks
Dom

 

It sounds about right (I'm taking from your post that you still have the cats in place)

The underdrive pulley and efan don't really do much for hp.

I believe the drivetrain loss is somewhere around 15%... someone help me out on that one.

 

the cats are inplace but i don't know if they are hollow or not.. . the kid i bought it from said they were i think but i'm not sure if i beleive him. . Anyone else. . lol thanks

 

how about the filter? it's an open element isn't it? could it be sucking in hot air and affecting the engines power?

 

yeah if the intake is under the hood then yeah you will lose a little hp becuase of the hot air, the estimate is 15% for front wheel and 10% for rear wheel, cats being gutted or not would make a little difference, gutted could cause some scavinging to be loss, removing a/c isnt going to make or lose any power becuase when the a/c is off it just becomes and idler pulley and if you had it running when you floor it the a/c shuts off anyway to keep from building the pressure up to much, unless the WOT cutoff circut is messed up.

 

Sounds like good dyno #s on the GXL!

Honestly your new GXL is probably over 200-300lbs heavier than the base was; GXL is heavier stock and your base soundsl like it had a over 100lbs in weight reduction from dropping the 3 cats and catback.

Exhaust mods also make the most difference in HP on rotaries and your base had them.

 

Stock S4 dyno at around 115 rwhp so I think thats not too bad

 

if i am not mistaking its 10% loss hp to driveterain

 

10% of 146 is 14.6, so stoke they should be pushing 132 to the wheels? 15% is 21.9 so that would be 124 to the wheels. that sounds a little better. but does anyone have graphs from a stock rx7? i would like to see them or at least get the number. if it's true that stock they did 115 or so then i think my numbers are pretty respectable. what do you guys think i will be pushing when i get the s5 upper intake mani, header, and throttle body on there? i'm hoping for maybe 145 or 150? i'm getting rid of the y pipe and going single. . i think. or side piped not sure yet. . thanks for all the input. any more would be great
dom