How can I get the extra 20 or so hp of the '89 tII on a '88 motor? What's the diff?

 

I believe that the 89+ engines have light-weight rotors and some other tweaks that give them a higher redline, also the wastegate on the turbo is different, makes a little more boost I think. There are some other small differences also.

 

you can do lots of **** to make up for it.
The biggest is Higher Compression
Second Lighter Rotors
89 turbo
89 exhuast manifold
89 intercooler
thats about it
but essentially a s4(88) motor can be made w/ more overall HP b/c of the lower compression. when i converted my gxl to a J-spec, Haltech, etc etc crazy *** turbo II guess which motor i picked. oh yes as rebuilds/j-specs they are generally cheaper too. my $.02
jason

 

get an intake, exhaust, and raise the boost to 8psi or so and you'll made up for more of it. might need an fcd too.

 

I agree with Scott 89T2.

 

For exhaust I think use 2.5" stainless tubing from the back of the converters to the bumper, with an X-pipe in the middle to equalize pressure. As for intake, I don't want a k&n does anybody make foam filters for RX? Also, intake, I want a cold-air unit like stock.

Also, where can I get the "MAZDA" decal on the airbox? I really want one.

 

foam filters suck, they don't filter. x pipe?? you mean Y? there is no need to equal pressure, it's still only basicly a single exhaust, you don't have a v8.... get a down pipe and high flow cat, you power will go way up. you could just get a drop in k&n to keep the stock cold air, other wise your have to build your own.

 

well, my tII has a dual exhaust.

a K&N doesn't filter very well, does flow tho.

 

All 2nd Gens have a pseudo-dual exhaust. Look under your car...see the y-pipe? If you want to open yer exhaust up and to lose weight, then you could simply run a single muffler system. That's what I'm doing, simply because of my budget and the fact that my 90 TII is porky enough.

Get an APEXI filter, I saw an independent study on them and they filtered the best out of any filter they tested...plus they happened to flow the best too.

 

yeah i see the y............ i am thinking about kicking the muffler and just having two 2.5" pipes from each catalytic.

 

it won't do anything but make more noise, if you want power you need to get rid of the cats, buy a down pipe and mid pipe. the bonez from www.rx7.com are good. anything bigger then that and you will need fuel mods. you probably will anyways though.

 

How's the INTERCOOLER different in 89? I thought it was exactly the SAME!

 

I think the inlet hole is bigger.

 

*cough* PORT IT!

 

Will that HELP create more POWER or better FLOW?...cause I can take mine to a MUFFLER SHOP and have them FLARE it up...I've seen 'em do that to muffler pipes so that they fit over a bigger pipe diameter.

 

isn't the hole plastic?? can't flare that... the 89-91 is metal but it's super thin.

I think the hole size is the same but it gets biger as it gets to the IC.

 

oh well, get a FMIC lol
but anyways don't just try to get a 89esque motor, just upgrade it to as powerful as you want, one thing that helps a little bit and will be an upgrade you can use all the way is removing the belt driven fan with an electric fan you bought or got in a junkyard.
Go to a junkyard and get a big one, there was a thread about this maybe a week or two ago, try searching for it. Only frees up maybe 2hp or so but its still more power. Some people say they can feel it.