Ok, so today on my way to pick up an ICEE at Circle K, my Integra started to smoke out of no where, and I tried to lay off the boost until I got home, when I got home I lifted the hood, and saw that it was smoking around my downpipe/manifold area. After checking, I saw that my Traingular gasket for my DP elbow was wasted, so now, instead of letting history repeat itself, I decided to get rid of the entire DP, and fabricate/buy a 3.5 inch one, so my question is will a 3.5 inch DP fit under an Integra easily?

B18C1
TD05H - 18G turbo
custom piping
Orginal Skunk2 IM
Greddy Cast Iron Turbo Manifold,
and a random name brand IC, forgot the actual name.
and other non-turbo related stuff.

 

I don't think you should be smoking in any case. Perhaps you have other problems aside from a broken downpipe.

And why do you need such a large DP for such a small turbo?

 

I found out it was burning oil, as to how, I have no idea, but the gasket, seems to always be the culprit, when this happens, usually, and I leak oil, but only a small, small amount.

I just went of the physical fact that the wider a pipe, there less fluid resistance, but IDK how big is too big, besides that 4 inch is racing width,
I would go with 3 inch DP, if the 3.5 to 3 inch HP diffrence is negligible, not to mention I'll get a DMH E-Cutout, for half price, so thats a plus. I've been wanting a bigger DP for while, just never had a scenario when it was a good time to buy one

 

3" is enough for your setup

 

Yes. stay with your three inch with that one. at 41lbs/min, not worth the time, effort, or "performance".

 

alright, thanks, I actually had the 2 inch Greddy DP, it was terrible!
and a 3 inch DP + an E-Cutout = :D

 

Even though your question is already answered, it all really depends on the suspension and ride height. I have full 4" run the entire way under my car. Stainless running to the flex bellows, then v-banded to aluminum the rest of the way back.

 

regarding the ride height, I'm very sure that a 3 inch will have enough ground clearance, but I though about making the pipe have a slight oval shape, will that affect the flow at all, if the overall area is kept the same?

I also took apart the whole DP assembly, and the hole for the bolts on my triangular flange is broken so, I gotta buy one eventually, not really in a rush, No school hahah

 

as long as the cross sectional area is the same, no it should not affect flow.

 

Oval pipe won't affect flow as it has the same cross sectional area... Be warned oval piping is expensive and no one makes vertical bends so you'll have to pie cut it

 

do you still have ac? if so even fitting a 3" down pipe in there is gonna be really tricky. on a side not I tuned a ls turbo teggy with a greddy kit on 16lbs and it was a really fun car. minimal lag and a good amount of power.

 

I've seen people run a 3" downpipe on a Greddy it while still retaining ac
it takes some tricky bends but is doable.
To the op. Eliminate the Greddy elbow and get a flange from atp. This eliminates a big bottle neck and you'll have better boost control and quicker spool. I would also port the external wastegate while you have everything off. This leads to more precise boost control as well

 

3.5" will fit fine under a DC. I made one from aluminum that I don't use anymore. If you're local you can have it. Lol

 

Well since I'm going 3 inch, the whole oval idea was just out of future projects, and I honestly want to tkeep the idea of an internal wastegate, just like the idea better :\ but If anyone knows a diaphragm for the TD05H-18G that is a higher PSI than 8, PM me

 

im not talking about removing the internal wastegate..... ugh.
remove the stock greddy turbo exhaust outlet, its really restrictive... replace that with a flange from atp that bolts to the greddy turbine outlet and allows the use of 3" pipe..
while you have that off unbolt the internal wg actuator so you can move the flapper... the hole behind the internal wastegate flapper... port it, the hole is a tad on the small side and causes issues.
doing none of this entails the loss of the internal wastegate, it simply makes it work better
no one makes a higher pressure wastegate for the greddy stuff.... just buy a manual boost controller