Modified exhaust question...

[pastadog]

Hello ladies and gentlemen :wave1:

I have gone through the archives on here and TVP looking for any valuable information on upgrading my exhaust and come across nothing. So, simply put it looks like my 84 LE 3Y runs a 1.5 inch piping and was thinking about upgrading to 2 inch piping with a stock muffler off of another car that runs 2 inch stock piping for a little better flow.....

Let's hear your thoughts, your likes, your boos or simply your dumb..... :rol: Also would like to hear your advise and or ideas!!

For 100 bucks I think a little better flow would be nice and my van would probably love me a little more :dance1:

[timsrv]

IMO there is nothing wrong with the stock Toyota exhaust system. If it needs repair or replacement I would do what's required to get it back to stock specs, but I don't see any advantage to going any further. But then again I'm lazy and don't want to create any extra work for myself :wnk:. Tim

[pastadog]

Ha ha ha Tim your awesome and such a big help to all of us on here and the whole Toyota van community.

Now enough sucking up, on my part, and onto the exhaust. I wasn't going for noise or anything just a little easier to breath from the cat back.... but probably pointless?

Thanks,
Ronnie

[NEC]

There was a guy recently on TVP who posted about his modified exhaust. Since I needed to replace my exhaust anyway, I ended up copying his design. I picked up a 2.25" "flowmaster" knockoff muffler (Thrush brand) and a high flow Magnaflow Cat. I actually printed the pics from tvp and gave them to the local muffler shop. I had the cat moved forward about 12" from the stock location and the muffler located directly behind the cat. I had the exhaust shop custom bend the tail pipe from the muffler back and use the stock rear mounts, adding their own mount at the muffler (tack welded to the rear suspension crossbar). I haven't yet got enough miles on it to tell if I have better performance/mpg but I am very satisfied with the sound/performance. It is a lot louder than before but it is a reasonable volume for me. Cruising on the highway does not cause the droning which makes you feel your head is going to explode but accelerating will make for some nice hotrod type noise. Before the muffler upgrade it would shift around 4k rpm when floored. Now It revs to about 5k before shifting. I figure this is because of less restriction in the exhaust. The exhaust work cost me $150 plus 100 for the cat and 40 for the muffler. Sorry no pics now.

[NEC]

IMO there is nothing wrong with the stock Toyota exhaust system. If it needs repair or replacement I would do what's required to get it back to stock specs, but I don't see any advantage to going any further. But then again I'm lazy and don't want to create any extra work for myself :wnk:. Tim

On that note: I have created more work for myself by moving the cat forward. My cat is now closer to the charcoal canister and transmission, and not protected by the stock heat shielding. I also had to remove the stock heat shielding from the down pipe to make room for welding. I have not yet compensated for all this extra heat near my valued components but I am planning on using a salvaged heat shield I got from a Venza as it is very large and should do the trick.

[timsrv]

When you get a chance please post pics! Sounds like a interesting mod. I'm not much into cool sounds or more noise anymore, but I went through that phase so I understand what it's all about. I'm at the point now where I enjoy surprising people when I roll up behind them in parking lots (van's so quiet they don't hear me sneak up on them) :)>:. I like quiet vehicles now, and the stock Toyota exhaust system does a pretty good job. Tim

[pastadog]

When you get a chance please post pics! Sounds like a interesting mod. I'm not much into cool sounds or more noise anymore, but I went through that phase so I understand what it's all about. I'm at the point now where I enjoy surprising people when I roll up behind them in parking lots (van's so quiet they don't hear me sneak up on them) :)>:. I like quiet vehicles now, and the stock Toyota exhaust system does a pretty good job. Tim
Yes PLEASE post some pics!!! And I'm right there with you on the not a big fan of lots of noise Tim.... I went through that phase as well but now like being sneaky like a ninja :wnk:. So with that said, anybody know of a muffler? And also, would 2.25 piping be to big for the 3y? Lose a lot of back pressure?

Thanks Tim and NEC!

[pastadog]

???? :cnfsd::wave2:

[NEC]

About back pressure: people say you need the smaller pipe for low end torque when wheeling/etc. I haven't noticed any real loss at the low end (it's still gutless as always with the big tires). I have noticed a little more top end performance though. It pulls harder above 3500 rpm and revs about 500 rpm higher before shifting when floored. I assume this is due to the less restrictive exhaust. There are several brands of quiet mufflers available in 2.25". Typically, any muffler not marked as "performance" will be quieter and should still flow good enough for our vans. I'm over the loud muffler stage in my life too, and It should be noted that I would probably hear a lot more noise from my muffler if I didn't have the sleeping platform installed and packed with gear/bags/bedding, etc.

[pastadog]

Awesome info NEC!! SO you think I should go with 2.25 over 2? Mine's a 2wd and stock tires so I'm not really worried about that low end torque while wheeling ha ha.

Have any of you thought of going under the rear diff with the exhaust pipe? I looked at it and it very possible, at least on the 2wd's. The reason I ask is because my friends and I use to do this on our lowered drift cars and subaru's with NO problems....... Brings me to wonder why I cant do it on my van :)>:

Let's discuss the god's and bads and if I'm going to be the first to try :LOL2:

[pastadog]

Have any of you thought of going under the rear diff with the exhaust pipe? I looked at it and it very possible, at least on the 2wd's. The reason I ask is because my friends and I use to do this on our lowered drift cars and subaru's with NO problems....... Brings me to wonder why I cant do it on my van :)>:

Let's discuss the good's and bad's and if I'm going to be the first to try :LOL2:

Any thoughts on this?

[pete]

I would like to run my exhaust under the axle. It' does not seem like there would be any clearance issues. I have 3 camrys and they have low rear pipes. I'm sure everyone sees them from behind and have noticed that about those cars and have never been an issue for me.

If anything I have problems with the exhaust going over the axle on my vans because i'll do a job (tree or concrete usually does it) where the axle hits the pipe from overloading and bends it and usually breaks somewhere down the line. Then once again I am doing an exhaust repair. I now have my pipes above the axle custom bent as high above the axle as they possibly can go.(too lazy to modify suspension). But to have the exhaust system lower is also way easier for access when welding.

I see the time part is figuring and doing new support brackets.

Ps. When moving the front of exhaust around and heat shields ect.. I have had two vans and others have as well with glowing red hot manifold issues. It was not timing or TPS or O2 sensor. Never did continue to track it down. Maybe somewhere in the head.

[pastadog]

I feel the same way about the clearance part, plenty of room! I really want to try but now which muffler, cat and size piping.....

[timsrv]

It's an issue of suspension travel. The rear axle should be able to travel completely from unloaded to loaded without interference from anything. The travel zone is controlled by the limitation of spring travel (when unloaded) and the rubber stops (when bottomed out). Running anything rigid inside this travel zone is frowned upon and should be avoided. This is why manufacturers always run exhaust pipes over the rear axle (on solid rear axle vehicles).

Can the pipe be run under the rear axle? Yes it can. For the most part it will probably be okay. If the pipe is tight against the axle , it will travel up and down with the suspension and this will create noise and lead to other problems. It would be better if it had a few inches of clearance, but the pipe may still hit at times of severe driving conditions and/or when jacking the vehicle up for servicing. If the pipe is installed low enough to not be in the "rear axle travel zone" then it will most likely be too low and may hit on speed bumps or other irregularities in the road. Even bigger problems for those who take their van off the paved road.

I'm not saying it can't be done, I'm just stating the reasons for it being above the axle. If you slam (lower) the van to an extreme amount, you may end up needing to run it under the axle, but at that point the exhaust will be a minor issue compared to the other compromises made to ride comfort and vehicle usefulness. Tim

[pete]

What about running it out the side before the axle ?

[timsrv]

Maybe you could split into dual exhaust then run 2 pipes......each one aiming at a rear tire. This would heat them up for better traction :yes:.

[pastadog]

ha ha ha

[timsrv]

Maybe you could duct it inside the van to keep you warm while driving :LOL2: :yes:

[pete]

Or more economical, run it into the hot air balloon system. But that's only when I solve my cut off at idle problem at 2,500 feet altitude.

[pastadog]

So I take it that the under diff will work fine with the right fit....

Now for the last question....... 2 or 2.25 piping?

Thanks