Designed a 4" Oval exhaust system for my S13 that will be exiting the side of the car through a custom steel tunnel that directs the exhaust ABOVE the frame rail for ground clearance purposes. This system was started from a custom front facing topmount manifold hosting a Precision Billet 67mm going through a 4 round to 4 oval trasition and sectioned by the steering shaft in 4" Oval (section cutting Oval is wonderful!).





The tunnel has it's shape but isn't completely stitched up yet. It was done with 1/8" steel for strength purpose and it is stronger then it was from the factory so there's no issue with rigidity.



The first section into it's 4" V band is completed. The rest will be mocked up and welded when the cars back from paint. I used 4" Oval vertical-horizontal (Tomahawk) for steering clearance and then to be above the frame since the car is burried on the ground and will continue to be that way for the road.

 

Badass....

Ive been planning something similar for my s14.

 

Sick car!

 

That's cool. Ton of work. Nice job so far!

 

thanks guys i've put a TON of time in but it's been a blast building! Time to do some driving though..

 

Nice! Did you fab your own oval tubing or was it brought in?

 

Oval tubing was mandrel done for me

 

I found some pictures of when the tunnel was started and where it sits just spot welded up.





Sideskirt will be trimmed to accept the 4" oval outlet..

 

Is doc race in your house?

 

Wish I had enough room at my house for everything I need

 

that thing is baller! very nice.

 

That's gotta suck to drive, do you miss your handling much?

Exhaust looks cool though

 

No that's a friends garage that's working on my flares.

 

Thanks.

As far as suspension geometry goes this is far from where the car sits. I have drop spindals and spherical bearing control arms I made with a extended shank fixing all my arms

No SUCK to drive over here! From the current view of my arms I see your concern! Nothings been overlooked on this project just a ways from final stance.

 

What wheels ?? And offset?

 

SSR MS1 17x10 +6 18x11+3