New rims, caliper paint, lowered and exhaust gut pics...
#1
Instructor
Thread Starter
Join Date: Mar 2011
Location: Fort Lauderdale, FL
Posts: 248
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I said I would post these awhile back so here goes...
I lowered the front of my 88 S4 by 1", I think I am going to go another 1/2" tomorrow (little more sporty), handles great...up front 19x8.5 (235/35/19) and in the rear, 19x10 (285/30/19)...no rubbing or bumping and I ran it hard today...
Had the calipers painted yellow (I know I wanted a darker tone but thats all they had)
Gutted the exhaust and went to 3" pipes, 8 into 2 into 1 all the way back, saved a ton of weight and sounds like a vette now or street hotrod...sweet....grumble (no noticable performance improvements...
enjoy, going to install Recaro fixed racing seats next,,,
I lowered the front of my 88 S4 by 1", I think I am going to go another 1/2" tomorrow (little more sporty), handles great...up front 19x8.5 (235/35/19) and in the rear, 19x10 (285/30/19)...no rubbing or bumping and I ran it hard today...
Had the calipers painted yellow (I know I wanted a darker tone but thats all they had)
Gutted the exhaust and went to 3" pipes, 8 into 2 into 1 all the way back, saved a ton of weight and sounds like a vette now or street hotrod...sweet....grumble (no noticable performance improvements...
enjoy, going to install Recaro fixed racing seats next,,,
#2
Instructor
Thread Starter
Join Date: Mar 2011
Location: Fort Lauderdale, FL
Posts: 248
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
yeah yeah the guy I bought it from put the turbo emblem on, since no one has told me anything I will leave it for now to confuse the 911 guys... : )
#4
Nordschleife Master
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Ugh...either actually PUT a Turbo on it or take the damn sticker off... Then go slap the CRAP out of the PO for being such a putz!
Other than that ONE oversight the car looks GREAT! really like it!
Other than that ONE oversight the car looks GREAT! really like it!
#5
Under the Lift
Lifetime Rennlist
Member
Lifetime Rennlist
Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Did you adjust the toe after lowering? I observed 1/2" change in toe per 20 mm of rideheight change. Of course 1/2" (measured with 24" toe plates) is monstrous.
Trending Topics
#8
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Going from 2 2.5"pipes to a single 3" pipe sounds like it will increase the back pressure... which would be contrary to a gain in performance -IIRC.
I agree with Bill & Colin 100%... once the ride height issue is settled -get your 4-wheel alignment ASAP! Better yet, throw in corner balancing at the same time.
I agree with Bill & Colin 100%... once the ride height issue is settled -get your 4-wheel alignment ASAP! Better yet, throw in corner balancing at the same time.
#9
Administrator - "Tyson"
Lifetime Rennlist
Member
Lifetime Rennlist
Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Stole this from a different forum:
Here we go...
The surface area of a 2.25" pipe is effectively 3.9760782021996".
The surface area of a 2.5" pipe is effectively 4.9087385212341".
The surface area of a 2.75" pipe is effectively 5.9395736106932".
The surface area of a 3" pipe is effectively 7.068583470577".
It's better to deal with surface area than diameter, for several reasons. It gives a better idea of how much the gases are capable of expanding ******d.There's a significant difference between the 2.5" and 3" sizes. If you run a single 3", you'll be better off than running two 2.5" pipes (7.068583" of surface area as opposed to 9.817478" [almost a full 3" of surface area]), unless you're looking for the horsepower.
So- bottom line, if you're going to run either single 3" or dual 2.5", go with the single 3". You'll produce significantly better bottom end torque than with the duals.
The surface area of a 2.25" pipe is effectively 3.9760782021996".
The surface area of a 2.5" pipe is effectively 4.9087385212341".
The surface area of a 2.75" pipe is effectively 5.9395736106932".
The surface area of a 3" pipe is effectively 7.068583470577".
It's better to deal with surface area than diameter, for several reasons. It gives a better idea of how much the gases are capable of expanding ******d.There's a significant difference between the 2.5" and 3" sizes. If you run a single 3", you'll be better off than running two 2.5" pipes (7.068583" of surface area as opposed to 9.817478" [almost a full 3" of surface area]), unless you're looking for the horsepower.
So- bottom line, if you're going to run either single 3" or dual 2.5", go with the single 3". You'll produce significantly better bottom end torque than with the duals.
#10
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I think the original pipes are 2.25, not 2.5, but even with that, going from two of them to one 3 inch pipe reduces the flow area by almost a full square inch.
#11
Been selling Twinkies on Ebay,
have some extra cash right now.
Rennlist Member
have some extra cash right now.
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
^ I am assuming by Hacker's post that he is saying that boundary-area friction is the cause of backpressure, not lack of volume. ^
![popcorn](https://rennlist.com/forums/images/smilies/popcorn.gif)
![popcorn](https://rennlist.com/forums/images/smilies/popcorn.gif)
![popcorn](https://rennlist.com/forums/images/smilies/popcorn.gif)
![popcorn](https://rennlist.com/forums/images/smilies/popcorn.gif)
![popcorn](https://rennlist.com/forums/images/smilies/popcorn.gif)
#12
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
There's actually nothing in that quote to justify the conclusion. In other words, what is there in the area analysis and comparisons the can be added up, subtracted, multiplied or even divided that results in the "bottom line?"
Not saying it is wrong, just that it doesn't follow; and it is certainly not "intuitive."
Jerry Feather
Not saying it is wrong, just that it doesn't follow; and it is certainly not "intuitive."
Jerry Feather
#13
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I think that the use of the phrase "surface area' in his quote is referring to the cross sectional area of the tube and not the area of the inside surface of it. JF
#14
Administrator - "Tyson"
Lifetime Rennlist
Member
Lifetime Rennlist
Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I could have also gone into how many more bends are in a typical dual arrangement, then we can discuss mandrel bent tubes....do we know the wall thickness of the two pipes to know the actual ID?
X-pipe
Y-pipe
H-pipe
O-pipe
Then we have the Kibort factor.....
![Big Grin](https://rennlist.com/forums/images/smilies/biggrin.gif)
I only said: "It's not that simple"
![Wink](https://rennlist.com/forums/images/smilies/wink.gif)
That may not have been the best post to quite but I'm too lazy to do the math myself and it was the first one I found
![Stick Out Tongue](https://rennlist.com/forums/images/smilies/tongue.gif)
#15
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
You are correct sir... it's not that simple.
I do know on any V or H (horizontally opposed) motor with dual exhausts, there is a lot of benefit from having an H-pipe to balance the exhaust pulses... even more so with an X-pipe.
What sniper did was to create a Y junction and increase the pipe diameter south of that. While a single pipe may work fine for inline 4's or 6's... I think he has actually lost performance with this mod.