Can i use 3" exhaust pipes on a stock turbo t5?
 

i just bought a 1998 volvo s70 t5 and would like to know about upgrades and what should i start off with? i saw on youtube some t5s with 3" systems and was wondering will that be ok with a stock t5? i was thinkin to have a muffler shop remove the stock exhaust system and replace it with 3" pipes with a high flow cat and muffler on back...should i get a metallic cat or ceramic?

Go for it. 3" turbo back would do good. Would will lose some lowend torque, BUT the mid to top end power will be better.
If not...go 3" downpipe high flow cat to 2.5" cat back.

You need straight through mufflers like dynomax and magnaflow.

1. Welcome to the forum.

2. DO not mod your Volvo until you have done STAGE ZERO.

PLEASE LOOK AT THIS LINK below.
https://volvoforums.com/forum/general-volvo-chat-5/volvoforums-resources-thread-7317/

Plugs
cap/rotor
oil/transflush
filter (oil)
hoses (the little vac lines)
samco hose kit (Turbo Models ONLY)
02 sensors
fuel pumps
clean injectors
clean IC/IC plumbing (Turbo Models ONLY)
Air filter
plug wires

3. The most common mods are these, Intake / Downpipe / Catback / ECU upgrade. In that order too is the best way to do it or all at once.

4. Intake... IPD USA or EST short ram, or go custom.

5. 3" mandrel bent downpipe to a Hi-flow CAT. Go custom or look at IPD USA, EST, Viva Performance...

6. 2.5" or 3" mandrel bent catback system to a free flowing straight through design muffler such as a BORLA or Magnaflow. Go custom or look at some of the prefabbed systems from EST, Viva Performance, IPD USA, etc...

*You go can full three all the way and you'll be good to go.

7. ECU upgrade, this should be done last after all your other engine mods. It will take into account what you have done to your car and gain you the most potential from all those parts. IPD USA, RICA and BSR are the three best tuning companies for Volvo. They cost a lot too. SpeedTuning USA, Upsolute and Inmotion are cheaper alternatives and you get what you pay for.

here is the deal on this t5 i bought, this was all replaced now the car has 114k miles so when should i perform some of these things again besides oil changes and air filter? does the car take synthetic? and premium gas always?

AT 64,731

Manufacturer's recommended maintenance performed
Turbocharger oil line seal(s) replaced
Oil and filter changed chassis lubricated
Front wiper blades/refills replaced
Tire condition and pressure checked
Front brake pads and rotors replaced
Steering/suspension checked
Fluid levels checked
Cooling system checked
Cabin air filter replaced
Spark plugs replaced
Antifreeze/coolant flushed/changed
Brake fluid flushed/changed
Air filter replaced
Fuel filter replaced
Drive belts replaced
Throttle body cleaned/serviced

AT 70,505
Oil and filter changed chassis lubricated
Tail light bulb replaced
Timing belt/chain replaced

AT 84,194
Maintenance inspection completed
Manufacturer's recommended maintenance performed
Cooling system checked
Steering/suspension checked
Tire condition and pressure checked
Battery/charging system/starter checked
Oil and filter changed chassis lubricated
Fluid levels checked
Cabin air filter replaced
Front wiper blades/refills replaced
Alternator/Generator replaced
Front brake pads replaced
Brakes checked

Well replace all vacuum lines with silicone versions and replace your turbo hoses with silicone versions from SAMCO or Stylin Motors Inc.

Car doesn't require synthetic oil, but you can use it and I would recommend doing so. Mobil One.

Your car runs better on Premium gas, but it doesn't require it. Your car will run and run fine on regular.

i wanna go to a muffler shop and have them remove my stock exhaust system and use 3" pipes from the engine to a hi flow cat and then to a str8 flow muffler will this all workout? i saw the downpipe on 2 sites but its expensive do u know of a cheaper way of doin a 3" system without buyin that downpipe?

just go custom. $1100 for a downpipe is ridiculous. IPD is at least around $800.

3" all the way. high flow cat a bullet resinator and straight through muffer.

ok how would a custom 3" setup be? i wanna do a hi flow 3" cat to a 3" inlet str8 flow muffler...no resonators

what about the pipe commin down from the engine what size stock is it 2.5"?

i dont know the stock diameter....i have never measured it, but it is probably 2.5in.

expect to pay around $1000 for a custom turbo back for your setup.....3'' downpipe with a 3'' highflow cat to a 3'' catback with a single rear muffler.

Custom it can be done. Any shop that can MANDREL bend pipe is the way to go. If they can only crush bend I wouldn't go with that muffler shop. You want MANDREL bends only.

So either go to a shop that can MANDREL bend or buy mandrel bended pipes online and have a local shop make the system from that by cutting them up and welding them together.

Also it depends on what type of pipe you use. Aluminized Steel or Stainless Steal. SS is going to cost more, but last longer. But Aluminized Steel is going to cost less. I agree for a full turboback system (Downpipe, Catback) for a custom shop your looking at $800-$1000. If you bring them the piping for them to cut up and weld together maybe less.

how big is the stock downpipe 2.5"? what if i just replace the stock muffler with a 2.5" inlet turbo muffler will that give me some gains?

Cat back only, is not that much....The real gains are from the 3" downpipe.....

Can't answer the question about stock size. I have no idea. Go under the hood and measure it.

You will gain nothing from just adding a muffler to the system. Just sound and if that is all you want fine, but you wont gain power.

You'll also see the most gains from a downpipe upgrade.