I'm sure someones asked this before, but i couldnt find a thread about it.

Whats the main difference between the 86-88 146HP motors and the 89+ 160HP motors? Is it possible to switch a few parts and upgrade from the 146HP to 160HP?

 

about 14hp, the difference you will feel is the 160hp engine feeling a little more 'powerful' when you accelerate

 

Yea get an 89 engine.

 

Lol thanks guys... I mean, whats the difference in the engine to make that diff. Is it different rotors, intake design, or something more simple like an intake/exhaust mod?

 

compression, manifolds, afm, a/f ratio?, number of things. just better off getting the other motor!

 

a renesis has like 230 something around there hp. get that one.

 

The difference??? About 2 ft/lbs

a S5 non turbo makes more HP (but barely any more torque) than the S4 non turbo due to light rotors, higher compression, revised intake runners, and revised computer.

If you drive the two side by side, there is only a very little difference.

 

Thanks, that was the answer I was looking for...

 

i still vouch that the S5 motor was a better motor, but.........icemark and his S4's, no one can convince him, but i do totally agree that interior and production wise they spent more on the S4, but the S5 motor still wins me over


as far as upgrading, go with an exhaust, racing beat is great for an NA car, keep the catsbut set them aside and run a test pipe and save the cats for testing, do some type of CAI there are a few writeups lurking around here, im pretty partial to the fenderwell one and i will be posting a write up whenever i get around to it, SUSPENSION upgrades are you friend, especially on a vert, umm, unless you want to port the motor you really out of luck, you could do some other things to it but it would be more worth it in the long run to pop a T2 motor in there

 

Nearly all of the improvement came from the new intake manifold, which included the VDI (Variable Dynamic effect Intake) system to broaden the power band and improve top-end breathing. The was also a very small increase in compression ratio from 9.5:1 to 9.7:1 but that would only be good for 1-2hp. Improvements that don't affect peak power included lighter rotors with machined (instead of cast) combustion recesses, a lighter flywheel and better engine management.

If you want all the technical info, download and read this SAE article on the improvements made to the S5 engines. Very good info.

Part 1 (5.7MB), Part 2 (6.5MB)

 

i heard that spark plug placement helped too,

 

Not with power. The trailing plugs were raised slightly, which probably helps with emissions.

 

hmmm good to know, does that increase the burn spread burning off more fuel?

 

The difference is they both suck. A rx7 is not worth its weight until around 300-330 rwhp other than that it is over weight and under powered.

 

And can still run down cars with twice the power on the track....mustangs come to mind....

 

in your dreams they will

 

hmmmm.....

do you happen to have a video of a 200hp RX running up behind a 400hp mustang and blowing its doors off???????

because if you do post it and I'll send Ford Motor Company a direct link to it

 

Thanks for the responses guys... I dont know if anyone knows but im the guy with the 88 RX7 Vert with 29k original miles. I'm not looking to do anything serious to it -- no engine swaps, no huge exhaust replacements or anything. I was just looking to see if there was a simple way to get that extra 10-15hp. It sounds like a possible intake replacement might do it -- but it'll be a while before I do that.

 

a Racing Beat exhaust and a true cold air will get you what want hp wise

 

Replace your stock cats with a pipe+presilencer/high-flow-cat combo.

Cheapest and most effective way to gain power.

http://www.racingbeat.com/resultset....rtNumber=16209
http://rx7.com/store/rx7/fcexhaust.html

 

Sorry dude, the stock V8 mustang (pre-2005) packed 260hp (rated), and puts down somewhere around 220-230. They always WEIGH around 3400 lbs w/gas, w/o driver. And majority of GT's sold were Automatics ....

Let's see. 200rwhp RX7(2800 lbs or so, with little weight reduction), vs. a 230rwhp MustangGT (3400lbs or so), automatic, with horrible gearing. STOCK, my parent's Mustang GT(auto) ran a 14.5-8......They aren't very fast.


Now, the NEW Mustang's have better gearing (5 speed auto vs. 4 speed in the pre-2005), more HP, and around equal weight. THEY should not be messed with. The 2004 and before, however, can be dusted...

 

$305 for one muffler, 45 degree bend and some 2.5 pipe? Wow thats expensive. Or you could call Jegs.com and get everything in the RB picture for under 100 bucks. And a magnaflow will perform 100 times better that a RB anything.

 

You mean 9.4:1 right?

 

First how did a 146hp motor/160hp motor all of a sudden jump to 200rwhp? Any i have been on this forum for years and no one has got 200rwhp out of a NA that I have seen.

Second what the hell would a automatic mustang be doing on the track?

 

i just pulled mt S5 NA motor in favor of a turbo unit. If you want i could sell you the UIM with vdi. I heard people doing this on their S4 for a little more responce and power. Just looking to get rid of some stuff. PM if your interested.