Draw through turbo.....hard lessons learned, and passed on to you. YES they can be made to work well.

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My custom modified crown turbo system on my L series six. here are pics of what I fought through and learned lessons very valuable. The Crown turbo kits, are very basic, and were designed to use stock parts to get a turbo onto the engine, and this was back in the days of carburetors and point ignitions. the factory exhaust manifold is used and a "J" pipe, made by Crown bolted on to the bottom of it and curved up for the turbo to mount on. From that point the exhaust went to the right and down, and to the left was an adaptor, the carb, and then you had to finagle on your own a throttle cable, fuel line and air cleaner. It was designed without a wastegate....the idea being your foot is the wastegate....you have to be smart enough to know when to let off. The J pipe, I had to cut off the factory flange and weld on a flange for a T3 turbo housing. I had a welder do this and he had to do so that the pipes from the J pipe came into the flange with any gaps closed off. Here is where my problems began. on the factory Rayjay turbo, the turbo flange came straight down......on modern turbos the flange is offset. So, today, you either have to make a new J pipe that is a tighter bend to make the room necessary, or what i did, which was to cut a hole in the inner fender and part of the strut tower and run the turbo halfway into the wheelwell and angle the intake out and back into the engine compartment. This required me taking the wheel off and bending sheet metal around the turbo to close it off....in effect making a channel down the side for the turbo. I recommend NOT doing that. I would recommend using a 280ZX exhasut manifold and having a T# flange welded on, or getting the CX Racing turbo header and then using the crown pieces to get the charge from the turbo into the intake manifold. Also, I initially ran this on a Mikuni 45 HRS motorcycle flat slide carb, and then went to EFI. EFI is the only way to go. You will have to weld an O2 bung into the exhaust, and while I am thinking about it, know this, with a draw through turbo setup it is MANDATORY to have the turbo rebuilt with CARBON SEALS installed. "G Pop Shop" has done them for me, cost is under 200 bucks. you can't avoid it. without the carbon seals the turbo will create pressure that will pull engine oil through the regular seals and the engine will smoke like a chainsaw. Don't take anyone's word for it that it already has them.....pay the money have new ones installed and they go through the unit and you get back a turbo that will actually work. RLR makes the intake I used. It is made for a draw through turbo to be installed on a air cooled VW engine. In the Draw Through Turbo world, the only ones who anything about it are the air cooled VW guys and the Corvair guys. 99.9% of the people you talk to DO NOT know anything about them....and I was told I would destroy my engine, it wouldn't work, they are terrible, I was an idiot etc. This is not the case. (never got any apologies)...but they are a bit of a wild animal......in a carb'ed setup, you can only tune it to a happy medium, and that frankly sucks. they only run good when floored, every other time, they are a real pain int he neck. Don't debate it with me, I have lived it. spend 800 bucks and later go EFI anyway and the money you spent for that turbo carb was wasted. The Holley Sniper 2 saved me. BUT you have to unscrew the port plug and put the plug in the threaded hole on the bottom, the base....then install a 1/16 NPT nipple into the boost port. This allows the Sniper to make corrections based on actual air fuel ratios in the intake manifold, instead of a guess by the ECU from where the fuel enters the throttle body before being charged. Turbo Joe's is a page on Facebook, and he is the sole tuning source for making these work. Thanks to him, my car runs crisp and normal. The Water methanol injection is my intercooler , is set to start flowing at 4 psi and has added over 30 horsepower on it's own and allows it to run on pump gas. Spark plugs. NGK is the only way to go period dot. NGK BPR8ES..... 2 heat ranges cooler and go .031 on the gap. Well.....Good luck. There is a draw through turbo page on facebook as well. It is ran by a 240Z guy. Pics follow, Peace and God Bless. ~ Joe Guy 12-21-2025.

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I had the J pipe and down pipe cerakoted and then I wrapped them.  Makes a huge difference in heat management.