I've just installed The 3" downpipe that I bought from Ron, and I'm having clearance problems with the flexpipe,it is practicly in the ground. Do any of you guys with 3" downpipe have this same problem? Does anybody have any pics of one installed? My car is not that low either all it has is pro-kits and kyb.
http://www.sr20de.org/images/images/Sentra%20SE-R%20%28Classics%29/ground%20clearance.JPG

basically i think aot of us have that problem. I had a 3inch full dp on mine i crushed it to 2.5 by bottoming out. You should be fine with it hanging that low just as long as your car isnt slammed. I recently had a new full 3inch dp mandrel which clears the corrmember (above it) made by the same person who made the previous with a flex pipe. Cost me 150 alluminized piping mandrel bent. i will get pics. You could always have someone make the bend tighter on your dp if you have concerned about bottoming out. It worked fine on Rons when i saw it.


Larry

Thanks for the info, I would really like to see pics of your new dp. I don't know why my car is so low, all I got is 15" pro kits with KYB GSR2, this set up is not even 2 years old.
Hector

Originally posted by Low612
basically i think aot of us have that problem. I had a 3inch full dp on mine i crushed it to 2.5 by bottoming out. You should be fine with it hanging that low just as long as your car isnt slammed. I recently had a new full 3inch dp mandrel which clears the corrmember (above it) made by the same person who made the previous with a flex pipe. Cost me 150 alluminized piping mandrel bent. i will get pics. You could always have someone make the bend tighter on your dp if you have concerned about bottoming out. It worked fine on Rons when i saw it.


Larry

Larry:

Care to share with us where you got a 3 in. alluminized DP for $150? :)

GOOD GOD!!!
Take that lower oil pan off and make it round again!

What the hell did you hit with that thing:eek: :eek: :eek:


david lau

I bought a SR20Development downpipe for a GTi-R swap into a 96 200SX... have drove it at least 100 miles so far, car is pretty low but not super low... have had no clearance issues yet. Chris@SRDevelopment was very helpful answering some questions I had, and got the downpipe out to me the day I ordered it.

-Charles

Originally posted by phunk
I bought a SR20Development downpipe for a GTi-R swap into a 96 200SX... have drove it at least 100 miles so far, car is pretty low but not super low... have had no clearance issues yet. Chris@SRDevelopment was very helpful answering some questions I had, and got the downpipe out to me the day I ordered it.

-Charles

What size is this DP? How much did it cost ya?

I did'nt crush that pan the det came like that. I finally found another DET pan that I'll put in on my next oil change.

Hector( It looks awful right!)

I would take it to a couple muffler or High Performance shops that can weld. I bet you could cut that thing near the turbo flange and take out an inch or so to raise it to a better height. From the picture there is no reason for it to be so low except it was easier to make it sloppy then tight.

Steve

Jrios: I beleive the size is 2.5" on this pipe... I cannot recall the details since all of it was purchased in a hurry for a customer's install. The pipe was $250 or $350 I think... Sorry I am not much help... it was purchased and shipped overnight for a installation that the customer wanted done ASAP... I had the customer call Chris and pay for it herself.

-Charles

When you put the 3" dump pipe on, did you take off the 90deg flange off the back of the turbo, on mine it is only 2.5" inside dia, so thats the pipe size I'm running off the turbo. Also I was told that a 3" pipe would have trouble overboosting, that the wastegate wouldnt be able to work effectivly, any problems?

kiwi: the SRDevel downpipe I used did not replace the turbine outlet elbow (at least thats what its called on a Toyota, its thats what im used to). As for overboosting... I dunno about a 3", i think this pipe is a 2.5..., after the downpipe I put in a 2.5" high flow cat, and after that is a Greddy exhaust the customer supplied... probably only 2.25 or 2.5 since it was meant for the NA SE-R... with the wastegate running straight off the manifold for pressure source, peak boost is about 8.5 psi steady... This is a GTi-R motor. Boost never spikes over that... at least not that I noticed.... and this T28 spools so fast its actually ANNOYING! I never thought I would say something about a turbo spooling too fast... but man this damn thing I barely give it any gas just to drive in traffic and the turbo just starts screaming... at first its cool and all cause everyone loves those sounds... but after a while its like OK.. SHUT UP ALREADY STUPID TURBO!!! Its very loud, especially with no hood and the big intake... Most turbo cars you can drive around all day without boosting once if you want... there is no way to get anywhere in this car without boosting it.

-Charles

nah, the 3" downpipe is only avoided for clearance problems. on a T25 or 28 there isnt any power to be gained with a 3"

as far as overboosting, well, i had NO downpipe, just open elbow for a few days, and it stayed dead nuts stable at 6psi, no spiking at all

Its donest hurt the performance of the car to have 3" downpipe on a T25 or T28. It lags for a quick second, but thats it. Cause its gonna hella flow better then a 2.5, correct?

3inch dp there is less backpressure which is very benificial for turbos. I noticed a nice difference in power on the higher end of power band with my t-25 . As far as hp gain cant say but less backpressure=less heat for turbo

yes, but less heat for the turbo, means less turbine efficiency, which means more lag, etc. turbos harness the energy of exhaust, both heat, and velocity.

Hmmmm....that correlation doesn't make sense to me.

The turbine uses the energy from the hot gases expelled from the engine. The downpipe is downstream of the turbine. It's even downstream of the exhaust elbow - and if I remember correctly, extrude honing that exhaust elbow (i.e. making it flow better) knocks off up to 500rpms of lag. I would think running the biggest DP you can is best for the turbo - although as stated earlier, clearance becomes an issue. A 2.5" DP works just fine though.

I think what Larry meant to say was less backpressure = less WORK for turbo which means it will make it MORE efficient.

that is what i was pointing out. that less heat for the turbo means less turbine effeciency.

most people have noticed that with the T25, the 3" just isnt worth it, as it wont create enough HP to benefit much from a 3" downpipe. besides, your cat is 2.5" in/out, so it wouldnt really be worth it unless you upgraded that too.

i have also noticed that with no exhaust, the car felt more doggy off boost, and felt the same on boost, and was later to build full boost in 1st gear.

YMMV

I gained .5 seconds in the quarter mile and 4mph going at 7psi on a T25 going from 2.25" downpipe, stock cat, and Courtesy exhaust to open turbo elbow. Plus I could get to 140 like nobody's business :D

Dude, it spools so fast and the car just scoots with an open downpipe. If it only dind't make my ears bleed. Now my 3" mandrel is too quiet.