High Performance Tiger Exhaust System
An Article by Larry Paulick
- Now the mufflers. I have had very good experience with Flowmaster mufflers. They are well designed, well built, thick materials, and really deliver what they say in the way of performance. Again, dyno tests in the magazines..
You also want the largest muffler you can fit, to reduce noise. Because of the short overall length of the total exhaust system, which is really short, you can either cut down on noise and performance with a restrictive muffler, or chose the largest muffler, with good performance characteristics. Loud mufflers wear out real soon, on a long trip.
Flowmaster mufflers have a muffler that just fits as far as size, and has very good performance characteristics. Its the #42451 and is the largest muffler that I could fit under the Tiger. It will not hit anything, and will not add additional heat under the car. Cost is about $65 per muffler. They now have a TriDelta muffler that is suppose to be marginally quieter, is the same size, and just about $20/muffler more expensive.
- Now you need to look at the exhaust pipe material. There is steel, aluminized steel, and stainless steel. The prices go up dramatically, as well as the longevity of each material..
The area after the headers, including the H Pipe get enough heat that they do not suffer from the dread of most exhaust pipes, which is the acid in the water that collects in an exhausts system. This acid will eat a system from the inside out. The front part of the exhaust is not as prone to this deterioration because of the heat in this part of the system, and rapid flow of exhaust gases..
The muffler does collect acid water, and the only way to reduce the problem is to drill a 1/8 hole in the lowest part of the muffler to drain the acid water. Performance is not effected, and muffler life is increased..
The exhaust pipe after the muffler also collects the acid water, as it is the coldest part of the exhaust and thus, is prone to rust out the quickest..
What I did was to use aluminized steel from the headers, including the H Pipe to the muffler, and use polished ss after the muffler.
It would be better to have ss in the entire system, but this get really expensive, if you include the mufflers, for quality mufflers. Remember, you also need ss clamps, etc.
A trade off, of money and performance and longevity.
- Prices for the Custom Exhaust System. With a aluminized steel exhaust pipe after the header, H Pipe, polished ss exhaust pipes after the mufflers, including custom mounting tabs in ss, rubber mounting isolators, ss bolts and clamps, and installation, my cost was $450. I paid as much for the Flowmaster mufflers, and headers as the Jet Hot coating, alone.
Is It Worth It?
Well, all of this theory is good old hot rod science. The system looks good , and I will not have to change the exhaust system for many years, as it should last longer.
Performance. I had the car dyno tuned, on a Dynojet Model 248C Dynamometer. With no dyno tuning and just the muffler system installed for a base run, the rear wheel hp was 196 hp, and torque was 250 #-ft. This equates to adjusted figures of 245 hp, and 313 #-ft at the flywheel (with a 20% loss for trans and diff).
A stock 1990 EFI Mustang is rated at 225 hp at the flywheel.
The Dyno Guy said that the Mustangs he does normally have about 185 hp, at the rear wheel, to start with, if they are in top shape, with some mods already on the engine. They also have more stuff on them than the Tiger.
The final rear wheel engine performance after dyno tuning, yielded 237 hp (296 hp adjusted), and 277 #-ft ( 346 #-ft adjusted).
The torque curve is very flat, with approximately 245 #-ft at 1,800 rpm, and dropping to 250#-ft at 4,900 rpm.
The MSD rev limiter chip was cutting out at 5,200 rpm, but the max. hp and torque were already on for this stock cam. I have a T-5 trans, and a 3.54 posi, so torque is not a problem.
Good Luck with your project.
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