exhaust reccomendations - 4age

[sirsprinter]

hey all, ive running 4-1 extractors with 2 inch diameter, can anyone reccomend an exhaust setup for me,

should i just go a straight 2 1/4 all the way through, or keep it 2inch throughout?
its a smalport 4age and ive never paid for or had exhaust work before,so i wanna ask the been theres and pros out there who may be able to help

also

should i run a resonator>? why and why not if so? a mate said no, just to ensure even flow throughout, another said yes because i will appreciate its audible effects? ?

and

will my vehicle height affect an 'over the diff setup', im running 6kg king springs with KYB short strokes on the rear

thanks heaps guys.

[mrshin]

What's the car, and what's done to the motor?

If you're talking about a RWD Corolla, there should be no dramas with your over axle pipe in those sizes, 3" fits fine.

[Dimitri]

whats wrong with what you have now?

usually most people run a 2 1/4" on a 4age.

best compromise between sound level/quality seems to be running a "semi straight through" muffler towards the front of the car/start of the system, and a resonator/cannon at the rear.

ride height doesnt really effect the choice of over or under diff, though if you have a lot of suspension droop its possibly not a wise choice. usually under diff is cheaper/easier to do at home.

[oldcorollas]

i'd suggest running a resonator around the middle of the car.. ideally at the end of the tuned length part of the collector
the point of the resonator is to remove some of the higher, harsh sound, and it won't do that at the back of the car.
if you can't fit the resonator near the gearbox, run it before the diff

for the rear muffler, the largest chamber you can fit will be more effective.
in order of most effective (generally) to useless are:
reverse flow
dogleg
"turbo" (ie, not very good and only really useful for a turbo motor where the turbo is muffling the sound)
straight through.

they can all flow enough if you choose the style and internal construction and pipe sizes correctly (ie, go up a size or two on the reverse flow)..

you can get really cheap, very good muflers and resonators... ie, 2" ESA (exhaust systems australia) resonator for $25 (about 5 years ago )..

anyway, on eor two resonators and reverse flow will make you NOT a defect target.

single hotdog or a straight thru wanker cannon will make you cop bait.

edit: a mandrel bent 180 degree bend makes over the diff dead easy

[Dimitri]

nah, dont agree with you at all oc. im sure you have some science to back your theory, but ive built more than one exhaust for a 4age, and had a good look at a lot of good bolt on Japanese sytems. none of them are set up the way you described.

the set up i suggested i ran on my last Jap 86, and i never got pulled over. the car was Bright blue too so.. not overly loud, decently audible when you nail it, and a really nice note.

[sirsprinter]

im runin a smallport in my 86. Im just after recomended diameter for best performance, if to go up or down in diameter anywhere, and why, and where/if to have a resonator, i want a nice note, but not cop bait. Im fairly new to this.
Thanks

[The Witzl]

4age + exhaust = LOUD.

My recommendation for maximum comfort is a 2" press bent pipe, with resonator at front, and then a nice dogleg muffler with a restrictive flow.

I almost guarantee a poofteeth performance difference between that and a bleeding-ears fart cannon. Your girlfriend will be much happier to ride in the car also.

[sirsprinter]

4age + exhaust = LOUD.

My recommendation for maximum comfort is a 2" press bent pipe, with resonator at front, and then a nice dogleg muffler with a restrictive flow.

Thanks, but whats a dogleg muffler? And should i keep the system same diameter throughout, in and out of cat, resonator and muffler? Ive been getting mixed answers from people. also, i plan to run a "fake" cat, whch is a 2nd hand cat with pipe welded thru, just coz exhaust shop wants 240 bux to supply a cat. Is my approach recomended? Or should i skip the cat all together and risk it? Or shuld i fork the 240 and suck it up? Once again ive had mixed answers. Thanks

[sirsprinter]

4age + exhaust = LOUD.

My recommendation for maximum comfort is a 2" press bent pipe, with resonator at front, and then a nice dogleg muffler with a restrictive flow.

Thanks, but whats a dogleg muffler? And should i keep the system same diameter throughout, in and out of cat, resonator and muffler? Ive been getting mixed answers from people. also, i plan to run a "fake" cat, whch is a 2nd hand cat with pipe welded thru, just coz exhaust shop wants 240 bux to supply a cat. Is my approach recomended? Or should i skip the cat all together and risk it? Or shuld i fork the 240 and suck it up? Once again ive had mixed answers. Thanks

[sirsprinter]

4age + exhaust = LOUD.

My recommendation for maximum comfort is a 2" press bent pipe, with resonator at front, and then a nice dogleg muffler with a restrictive flow.

Thanks, but whats a dogleg muffler? And should i keep the system same diameter throughout, in and out of cat, resonator and muffler? Ive been getting mixed answers from people. also, i plan to run a "fake" cat, whch is a 2nd hand cat with pipe welded thru, just coz exhaust shop wants 240 bux to supply a cat. Is my approach recomended? Or should i skip the cat all together and risk it? Or shuld i fork the 240 and suck it up? Once again ive had mixed answers. Thanks

[Dimitri]

keep the same diam the whole system. with a near standard engine, 2" or 2.25" isnt going to make a perceptible difference.

the cat is a personal thing. it makes a big difference to emissions, but not a very big difference to performance.

the thing thats probably gonna decide it for you, is what the authorities attitude is towards them in your state, im from qld, so cant really comment.

[oldcorollas]

nah, dont agree with you at all oc. im sure you have some science to back your theory, but ive built more than one exhaust for a 4age, and had a good look at a lot of good bolt on Japanese sytems. none of them are set up the way you described.

japanese exhaust systems are generally shit they are noisy, drone, and the sizes are usually on the small side.
and usually only need to keep below 100dB.. some don't even do that (LegaliseR for example often = 105dB)

even on stock engines they sound loud and shit, let alone on a modified motor

the science.. = removing the annoying bits of the sound.. the ones that cut thru peoples houses and get you defected

as for cat.. with fines up to 10 grand.. do you really want to risk it?
$240 is a lot cheaper than $10K.... for deliberately damaging an emissions device
but check in SA what the fine is..

you know the EPA and RTA will only get tougher on them... and that there are cars making stock 300kw WITH factory cats...

[The Witzl]

keep one diameter the whole way thru.
2" press bent. No need for larger.... its a bloody 1.6L

Dogleg = not straight through. It forces the gas to follow a "dogleg" path through the muffler to interrupt flow, and thus restrict noise.

On my AE82 twinky... i have a 2" exhaust, cat and resonator... and the muffler is a stock muffler mated to the 2' pipe. Nice and quiet, and still works just nicely.

[sirsprinter]

keep one diameter the whole way thru.
2" press bent. No need for larger.... its a bloody 1.6L

Dogleg = not straight through. It forces the gas to follow a "dogleg" path through the muffler to interrupt flow, and thus restrict noise.

On my AE82 twinky... i have a 2" exhaust, cat and resonator... and the muffler is a stock muffler mated to the 2' pipe. Nice and quiet, and still works just nicely.

Sory about the reposts, im on my phone. Thanks for info guys. So lets have a vote. . I go for a 2inch system, resonator at front, over diff and dogleg muffler at rear, with a cat to play it super safe. Will this be a good decision? Wont be too loud? Thanks guys

[sirsprinter]

keep one diameter the whole way thru.
2" press bent. No need for larger.... its a bloody 1.6L

Dogleg = not straight through. It forces the gas to follow a "dogleg" path through the muffler to interrupt flow, and thus restrict noise.

On my AE82 twinky... i have a 2" exhaust, cat and resonator... and the muffler is a stock muffler mated to the 2' pipe. Nice and quiet, and still works just nicely.

Sory about the reposts, im on my phone. Thanks for info guys. So lets have a vote. . I go for a 2inch system, resonator at front, over diff and dogleg muffler at rear, with a cat to play it super safe. Will this be a good decision? Wont be too loud? Thanks guys