Project R35 GT-R, Saving Weight With a Greddy Titanium Exhaust System!

As we have complained about before, the R35 GT-R is a big heavy beast. In our previous segments of Project GT-R, we were able to carve off about 60 lbs of weight from the car whose tank-like stock 3840 lb mass is pretty impressive and not in a good way.

We are still in search of ways to reduce the car’s weight since we will be adding some weight back into the car as we start to modify the engine.  We anticipate that most of the weight gain will come as we add cooling capacity in the form of a bigger radiator, oil cooler, intercooler, and transmission cooler.

In the meanwhile, our first ventures into getting more power out of our car meant that we needed to increase the breathing capacity which means a freer flowing exhaust system.   The stock exhaust is super heavy and we felt that we could easily lose a bunch of weight here if we picked the right replacement exhaust.

The exhaust we did end up selecting was one that could best meet our requirement for weight reduction, Greddy’s Supreme Ti system

To meet our goal of having an exhaust that could balance weight with noise and free-flowing was the Greddy Supreme Ti.  The Supreme Ti is handcrafted out of titanium tubing for minimum weight despite its large diameter.

The most restrictive part of the GT-R exhaust is the Y pipe. Greddy’s large diameter Y-Pipe fixes this!

On lightly modded GT-R’s you can get away with the stock rear exhaust section if you replace the Y-Pipe.  The Greddy Y-Pipe is 80mm from the downpipes merging into a  huge 94mm single tube for maximum flow.

It is hard to get large diameter titanium tubing so the Greddy tubing is hand formed from titanium sheet and then hand TIG seam welded.

To get 94mm tubing to fit in the tight confines of the GT-R’s underbody and with the technical difficulty in bending thin wall, large diameter titanium tubing, the Supreme is not bent but made up of a lot of hand-welded pie cuts, JDM style.

Sometimes we might have been critical of this sort of fabrication when done as a show statement but in the case of this exhaust, it is a must. Titanium has a lot of spring back and with lightweight thin walls and large diameters, it is impossible to mandrel bend in the tight radiuses needed to fit into the car’s undercarriage.

6 comments

  1. It’s running the front cats. Most of the weight reduction is still coming from the material selection.

  2. It would be cool to see GReddy come out with a side-pipe kit for the GTR, where the exhaust comes out right behind the front wheels. That would save more weight, and require less material. I imagine the sound in the cabin would be brutal.

    1. It’s pretty technically impossible to do on a street car, it would involve cutting holes in the unibody.

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