Ok, I see there are many different hot side sizes to the hx35 which would suit the RB best, again looking for fast spool and good power. the chart shows like 4 or 5 different cm hx35s.

Thanks again!

Ok guys, school has kept me off the forum actively for about a year now, but I've recently started trolling again only to find a lot of questions about the Holset HX35 and its application to the RB series of motors.

The Holset, as has been said many times over, is a great turbo. It flows great, and is nearly bullet proof, plus they can be had for about $250 on ebay. I am going to talk specifically about the HX35, but much of what I say also applies to the HY35 (smaller compressor) and the H1C (slightly older).

Here is a link to the Cummings page about the HX35, for basic info on the turbo:

http://www.holset.co.uk/files/...5.php

So.... It all began when my previous turbo a TO4E just wouldn't spool fast enough. I set to thinking about cheap alternatives and quickly came across the HX35. Days later I purchased one off of ebay for $250 shipped and it arrived soon after. The turbo came internally wastegated, but I run an aftermarket manifold with an external wastegate (the XO2 top mount),so I removed the actuator and welded the flap shut. The specific turbo I purchsed also came with a V-Band adapter for the down pipe which made fabbing things very easy.

Here is my setup installed, which has remained the same (and reliable) for the past 6 months.

As you can see I run a "Greddy" plenum, Q45 throttle body, Z32 maf, all tuned on a Power FC.

The HX35, simply, is a large turbo. The compressor housing is almost 11 inches across at its widest point, so to fit it mounted to the top mount manifold, I had to shave about 2 mm off the compressor housing and the valve cover. Also the compressor had to be clocked pointing straight down, where its thinnest point aligned with the valve cover.

Now that the turbo was fitted to the manifold I had to hook up the oil lines. The oil return is the same as most T3 turbos as well as the stock RB dump tube, which I reused for the return. The oil feed is slightly larger than a standard T3 so I had to get an adapter to get my lines to fit. I cannot remember the exact size, but if anyone else knows, please comment. Also, the turbo is not water cooled so anyone converting from a stocker would have to plug those lines.

The compressor intake is 4 inches in diameter so a 4" to 3" silicone coupler was used to hook everything up. The compressor outlet, being clocked to the ground required me to rig my charge pipes in the crazy snake route shown. Soon I will weld a 90º bend to the outlet to solve that annoyance.

OK, we've come along way and the turbo is finally ready to sp-sp-sp-SPOOOL!

I will soon post video to accompany this section, but for now you'll just have to take my word for it. In second gear from a 2000 rpm roll about 20 mph for me, I mash the gas. Of course there is lag, but at about 2800-3000 rpm boost starts to build until at about 3500-3800 rpm a "spike" is felt when the boost jumps from 5 psi to 10 psi, where I have my gate set, and holds to the redline- 6900 rpm.

On my last tune the car put down 300 hp somewhere near the redline at just under 12 psi.

Off to work for now, but more pics and video will follow. Hope I've helped to answer alot of questions!