Lose of horsepower over the years...

admstng said:

I have read stories of ppl bringing their mustang to the dyno and finding out their mustang is putting out well under 200 horse.. I'm assuming this is due to many years of driving, beatings, etc...

my Q: what are the parts in the engine that wear casueing this lose of power? I picked up a 90' coupe and i want it to get "tunned up" forgive me for this Q, but, what are they going to tune on my car? lol. i'm assuming there going to check air/fuel ratio? my timing? change plugs, air/fuel filters... basically, i just want my car to be running the best it can be.. i hear ppl say they have "X" amount of "untunned" horsepower, i want my car to run it's best. any help is appriciated.

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your lucky to get 200rwhp, remember our stangs are rated at the flywheel at 225hp stock, so most of the time a stock stang will be even less than 200rwhp. Probably the biggest culprit is loss of compression as your rings and valve seals get older they begin to leak oil. Debris over time wear the cylinder walls, just the nature of an engine not really anyone or anything can do to keep it running like new forever, best thing to do when it starts to happen is just rebuild the engine and have your heads rebuilt.

well for an engine there basically 2 options, either you can rebuild simply, tear the old block down have, it checked for cracks, hot tanked, etc. and bore the cylinders .030 over and install a new crank, rods, pistons, rings, bearings.

Or most people will have the engine stroked which is the same as the above except the pistons and rods have different lengths allowing the engine to make more cubes = more horse power and torque.

Heads usually get the guides, keepers and seals replaced along with new valves. Your best bet is if you need to rebuild your heads its more cost effective to buy aftermarket performance heads. rather than spend 300 bux on a valve job.

engine rebuild all depends on the location, i've seen some basic ones cost 1500 bux for a .030 bore and strokers cost as much as 5k for the entire project.

I also suggest getting your timing chain replaced if you need an engine rebuild. your best bet is to buy a shortblock from www.coasthigh.com or dss racing and have your engine builder swap it out.

You should be able to get your shortblock rebuilt with OEM style parts (meaning no performance pistons, bearings, etc) for around $800 - $1000 with a good quality shop. If you have the money, and are rebuilding I would at least recommend putting a set of forged pistons into the car.

assuming the block doesn't have a ton of miles on it and the cylinder walls are not scored, a hone job should be fine for cleaning it up and you wouldn't need to buy new pistons (that's also assuming your's are in acceptable shape).

its impossible to say what the motors needs without at least pulling the heads though.

If you want to know what they are going to do when they tune up your engine, ask them. Different shops have different ideas. You could do it yourself and save some $. Basically its plugs, wires, cap and rotor. Get a simple Haynes manual and read it if you are new to car stuff and wanna learn a little. Also hang around here and read.

You can get a compression tester and vacuum guage and check out the general condition of your motor before you put $ into it. The guages can be had for $30 or so total, and come with good instructions on how to use them.


Does your car seem to be running well? Pull the self-diagnostic codes from the computer, it may be a sensor or something simple like that.

i dynoed my car when i first got it with the only mods being gears clutch and shifter. no hp adders not even mufflers, stock h every thing stock. around 120k pulled a 211hp and 274ft-lbs . i was really happy with those nums especailly after i looked in 5.0mustang & superfords and they had an 89 with intake manifod and cam and other small mods not even pushing that.