Exhaust size vs horsepower

[98TsiAWD]

It's a Tripple Threat Motorsports Full TO4 Monster supports 630 hp. It has custom housings A/R 63 and a trim of 50

To4e or to4s? The turbine housing is a .63ar? And the compressor wheel is a 50trim? Stage 3 or 5 exhaust wheel?

 

[wickedtsi]

To4e or to4s? The turbine housing is a .63ar? And the compressor wheel is a 50trim? Stage 3 or 5 exhaust wheel?

It's just a to4 it is a stage 4 turbo. Not sure what stage the exhaust wheel is. Here is their website. http://www.3tm.50megs.com/custom.html

 

[NDgsx]

I am going to have problems is #1 finding a 3.5" flex section, #2 ground clearance from the flex.

Diesel shops have them. Do not use a bellows style flex section.

 

[sweet97]

The supra guys are running 4 and 5 inch systems now. I've been running a 3.5 setup for about a year or so now and it rocks. Still pretty quiet, and picked up power on the dyno. Since we have a dyno, my car gets before and after tests for just about every part that I add.

Here is some piping differences. 3.5 inch from my system on the left, then 4, then 5 and finally the all mighty T25.

Here is a pic of my 3.5 setup that's kind of a RE Amemiya Dolfin knock off. It uses a magnaflow 3.5 oval stainless race muffler and a dynomax bullet muffler as a resonator.

jeff

I like the pic of the car. WILD! If my cat was missing, well, I guess if you fired the motor it would throw the cat into the next county! (without hair!)

 

[definitiveno]

swordfish, I was able to find a 10 foot piece of 3.5 for 69.99 and a 90 degree mandrel bend for 40.00 bucks, now I can't find a flex section, flanges or high flow catalytic converter. Know any body can hook me up?

 

[Morphius]

swordfish, I was able to find a 10 foot piece of 3.5 for 69.99 and a 90 degree mandrel bend for 40.00 bucks, now I can't find a flex section, flanges or high flow catalytic converter. Know any body can hook me up?

Read here:
http://www.dsmtuners.com/forums/showthread.php?t=145137&highlight=flex+section

 

[JwUoNoG]

I have a friend who swears that no exhaust at all is best in a turbo application. Wouldn't this reduce your low end torque?

 

[sweet97]

Try www.kteller.com under exhaust. Mark
PS: I got a SS Magnaflow through themI need tosell.PMme if interested. 5"x8"x18" body.

 

[definitiveno]

Since answers vary so much I just wanted to see if you guys think a 3.5 is beneficial for my setup.

fully built auto trans
9.5 billet converter (4500 stall)
50-100 NO2 (hole shot)
gt30r at 25 lbs (pump gas)
heads ported and polished
3 angle valve job
springs/retainers
fp2's
magnus
slowboy mani
9k revlimit
dsmlink
water injection
stock block


I am shooting at 400 - 450 awhp DD

3.5 or 3 incher.......?

 

[NDgsx]

I have a friend who swears that no exhaust at all is best in a turbo application. Wouldn't this reduce your low end torque?

No. The turbine wheel will still provide backpressure at the head port, if you're on that train of thought. You do not need backpressure to make low end torque though.

 

[4SFED4]

Since answers vary so much I just wanted to see if you guys think a 3.5 is beneficial for my setup.

fully built auto trans
9.5 billet converter (4500 stall)
50-100 NO2 (hole shot)
gt30r at 25 lbs (pump gas)
heads ported and polished
3 angle valve job
springs/retainers
fp2's
magnus
slowboy mani
9k revlimit
dsmlink
water injection
stock block


I am shooting at 400 - 450 awhp DD

3.5 or 3 incher.......?

I think my 3.5" exhaust on my race car is a little bit of an overkill at this point. It is only 3" at the O2 to the oil pan, but I plan to upgrade the O2 section when I install my new motor with a relocated alternator and forward facing filter housing. I made 520WHP with my street car(also 1G DSM): Comp 101200s, 60-1 hybrid(C-16) through a 2.5" O2 and 3" oil pan back. Both of my cars run an Electromotive TEC II standalones and have fully built short blocks.

Note: the GT30R has a low enough surge limit with the right turbine setup and proper tuning you should be able to launch(<1.6 60's) just fine with the 4500 stall without the nitrous.

 

[definitiveno]

I think my 3.5" exhaust on my race car is a little bit of an overkill at this point. It is only 3" at the O2 to the oil pan, but I plan to upgrade the O2 section when I install my new motor with a relocated alternator and forward facing filter housing. I made 520WHP with my street car(also 1G DSM): Comp 101200s, 60-1 hybrid(C-16) through a 2.5" O2 and 3" oil pan back. Both of my cars run an Electromotive TEC II standalones and have fully built short blocks.

Note: the GT30R has a low enough surge limit with the right turbine setup and proper tuning you should be able to launch(<1.6 60's) just fine with the 4500 stall without the nitrous.

I know that they can brake boost and launch quite well but I just don't like the idea of building 250hp from a stop while standing on the brake.

Another advantage to nitrous, there is no delay where i have to wait for spool, suppose I reach a stop light entering the feeder and a camaro hands me my ass because i hadn't made boost yet? I


What crank were you using on your race car and what boost levels did you run?

I am trying to take advantage of the gt30r's sweet spot (25psi) and use rpm to make more power. Just trying to make sure the car wants to make power up top, trying to make it peek in the 8500 9000 rpm range. the idea behind my setup is not to make ground breaking power figures, but to make the broadest power curve possible.

If fp can make 500awhp at 8000rpm with a stroker, I can make 450 at 9000rpm with a 2 liter.

 

[4SFED4]

The 525whp was to the front wheels only on the street car. It has a balanced, shotpeened 4G63 factory crankshaft. I was running 26psi of boost w/ 28 deg timing up top.

I agree brake boosting will take longer then just salpping a 50 shot, but I don't see it as a necessity so I don't use it. Plus if you plan on that kind of hp, a run of the mill Z28 even with a mildly modified LS1 won't stand a chance if you just leave off the converter. My street car will pull 1.8 60's w/ no brake boost, just flashing the 3500 billet conveerter. The race car has a 4000 stall with a larger turbo and can do the same. Even when I brake boost I only leave with between 15-20psi anything more shreads the tires on either car.

 

[definitiveno]

I had no idea the torque converter would work like that! From talking to john he said the car will feel like stock until I hit the brakes and gas.

this is all good news to me. Where did you buy your converter (mine is from IPT)

Maybe the nitrous is a bit presumtious until I get my trans back together, I have yet to even drive it with the new parts (billet TC, valve body kit, rebuild.....)

 

[4SFED4]

My trannies and converters(both billet) are built by Level 10. The car will drive/take off like stock if you are easy on the throttle, but if you slam the gas 1/2 throttle or more and your car isn't pig rich the billet converters flash right to the stall speed. I try to keep my a/f ratio around 13.0 up to 3500RPM and 150kpa. I love the billet converters and would never buy any other type after my experiance with them.

 

[anomalyinva]

I think my 3.5" exhaust on my race car is a little bit of an overkill at this point. It is only 3" at the O2 to the oil pan, but I plan to upgrade the O2 section when I install my new motor with a relocated alternator and forward facing filter housing. I made 520WHP with my street car(also 1G DSM): Comp 101200s, 60-1 hybrid(C-16) through a 2.5" O2 and 3" oil pan back. Both of my cars run an Electromotive TEC II standalones and have fully built short blocks.

Note: the GT30R has a low enough surge limit with the right turbine setup and proper tuning you should be able to launch(<1.6 60's) just fine with the 4500 stall without the nitrous.

You might see slight gains from a 3.5" exhaust, but you really are not making enough power on just the turbo to warrant it. If, however, you are also spraying a 100shot on top of full boost, you might get some decent gains.

 

[TheDeer]

Depends on how much power your end goals are, but with "your 630hp" turbo, then 3 inch should be fine. I made ~450awhp on pump with 3" all the way back from the turbo.

 

[definitiveno]

Depends on how much power your end goals are, but with "your 630hp" turbo, then 3 inch should be fine. I made ~450awhp on pump with 3" all the way back from the turbo.

At what rpm did you make that and when did power begin to fall off?

 

[1998gst]

The supra guys are running 4 and 5 inch systems now. I've been running a 3.5 setup for about a year or so now and it rocks. Still pretty quiet, and picked up power on the dyno. Since we have a dyno, my car gets before and after tests for just about every part that I add.

Here is some piping differences. 3.5 inch from my system on the left, then 4, then 5 and finally the all mighty T25.

Here is a pic of my 3.5 setup that's kind of a RE Amemiya Dolfin knock off. It uses a magnaflow 3.5 oval stainless race muffler and a dynomax bullet muffler as a resonator.

jeff

Jeff- The second pic is that a Thermal muffler? I like the work!!!! I am thinking about going with a 3.5 after I get through with the install and support. Was it a noticable gain? I have a dyno about 10 minutes from my door so I will be doing a before and after also but with yours mods and at set boost was the mod worth it? Do you happen to have a graph so we can all see what kind of power/torque you picked up. Again good looking work and keep it up!
-Mike

 

[TheDeer]

At what rpm did you make that and when did power begin to fall off?

Here is the first dyno, you can see the torque curve is flat the the turbo doesn't quit, this was only to 7K, so it had more, but that was the first dyno after the car sat for a year:

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It has since been dyno'd on 27psi (same timing, 17) on pump. It made around 450awhp at 27. When I get that dyno, I will post it. Fixed the dip also around 5K. I plan on doing a C16 and one more pump dyno, to complete the pump tuning.

 

[94Jettameowpsst]

I had a 3 1/4 in exaust on my 91 talon tsi. I only had a 16g so it was overkill. I noticed how smooth it accelerated tho but it was LOUD. Couldnt drive for more than 5 minutes w/ out getting a headache especially when you decel and the rpms are in that whiney note of 3500-4500 rpm range.
Edit: Forgot to mention my buddy has a 90-91 (cant remember year) audi s4 i believe its a 20v 5 cylinder w/ a tO4r turbo. He has used both a 3 and 3.5 in exaust and lets just say he didnt go 11.6 or so in his 4000lb car on the 3 inch. It all depends on your personal prefrence, if ur gonna do somethin, may as well get it done right the 1st time, atleast thats how i feel

 

[sweet97]

I have had the 3" w/straight thru muffler. Could not carry a conversation. I got a resonator welded into the "B" pipe and am going to fit a BIG polished SS Magnaflow, 5"x8"x18" body with dual 3" outlets. I mistakenly got a muffler with dual 2.5" outlets which is just a personal thing for look and would like to sell the one here, still 5"x8"x18'. PMme.Mark

 

[wickedtsi]

I received my 3.5" pipes today, their large but they don't seem too big. I have been talking to some racers and people who have done a lot of exhaust systems. They have told me that 3.5" is the right size if I am going to make 600hp. They had also said that with poly motor mounts and a rubber mount exhaust system that I wouldn't have to run a flex section. I am going to try running without a flex section and see if I end up with any problems. Worst case scenario is that I will have to weld up a cracked flange and install a flex section. I had Bought a Flowmaster Super 40 muffler, I am curious to hear the sound. They are supposed to give you some more hp and give a deeper sound. To my knowledge I have never heard of anybody installing a Super 40 on a DSM.

 

[definitiveno]

That muffler along with all flowmasters are junk. In muffler tests ive been reading the last few days the flowmaster was always in the bottom the the list for flow and at the top of the list for noise.........


Google "muffler comparison".

 

[wickedtsi]

That muffler along with all flowmasters are junk. In muffler tests ive been reading the last few days the flowmaster was always in the bottom the the list for flow and at the top of the list for noise.........


Google "muffler comparison".

Do you have a website that shows Flowmaster at the bottom? I Googled "muffler comparison" and only found comparisons for walker, Gene, Berklee and others but not Flowmaster. Another thing if Flowmaster is so restrictive why is it that they reduce underhood temperature?