Hey guys, I've yanked the stock paralleled turbo's and cast iron thermal disaster in favor of a lighter more efficient small single setup. Not a whole lot more power to be had with this turbo, but there should be lower under hood temps and a much more reliable turbo system.

Before everyone bags on me for getting cheaper parts, at least I'm not totally cheaping out on the super ebay specials. I've read descent reviews on all the products I'm using. nothing is going to blow up and take my motor with it.

I have installed:
-T04B T4 divided turbo from eBay, 1.15AR Hot, .50AR Cold. Grabbed a T04B center section off of a Diesel pickup at the wrecker to avoid shitty fans/bearings, using eBay turbo housings. (Center section not installed in photo's)
-OBX stainless reinforced divided equal length T4 manifold, Reemed the waste gate outlet to 50mm.
-50mm HKS race waste gate.
-eBay water pump and alternator pulley kit. (Billet, not anodized)

Yet to be installed:
-Banzai Racing blockoff plate kit.
-2.5" intercooler piping kit, going to custom cut and install myself.
-HKS ssqv BOV.
-KazeSpeed eBay stock mount intercooler.
-Downpipe.

My plan is to get it on a wide band at about 6psi, and slowly dial it up, If I see AF numbers over 11.5 I'll get a Power FC, upgrade my secondaries to 1000cc's, crank the boost to 15psi, get it tuned, and call it a day. If my 15PSI KnightSports ECU will handle 8-10PSI on the single I'll leave it.

Pictures

 

You need to do research before you spend money. Good luck with not blowing things up.

 

We'll see if you can control boost, and we'll see how long that manifold lasts before it cracks.

Good luck though, sometimes these cheap bastard builds are entertaining to follow. It sounds like you know what you're getting into.

 

Why would things blow up? The only thing that may not be able to cope with the single setup is my KnightSports ECU, if it can't I'm getting a power FC. I don't know if you read it or not, but the center section of my turbo is not from ebay, so my compressor/turbine wheels are of good quality.

I have a 10PSI spring in the waste gate, I've cut off a coil from the spring to reduce my lowest boost setting, and I have a turbosmart boost controller. I'll start from 6 PSI and watch my AFR's on the KnightSsports ECU, if I see something I don't like, in goes the Power FC.

The manifold in question actually gets really good reviews. Lots of guys with 10,000km on them with no issues, my setup should run about 300hp, so the manifold wont be pushed too hard really. I've gone over all the welds on the manifold with my tig and 308 rod, and added a strut off the manifold to take the weight off the tubes.

 

Cool - subscribed. I should search before posting but I saw that the rx-7 store sells an inexpensive (relatively) stainless exh manifold - it may be the same as the OBX, but I fell like they are pretty reputable and would not sell something that had issues. May not have the right flange for that turbo?

 

Can i ask what the point of going single was if your only wanting stock-ish power levels? Why not just go all out with reliability mods?

 

Probably for simplicity and reliability. The stock sequential system gets pretty hairy with the million vacuum hoses. I've had nothing but problems which is one reason why I'm going single, too.

 

I got my GT35R kit from rx7store.net last year and it initially came with a megan manifold. I've had nothing but problems with it because of how uneven the flanges are. Jason sent me one of the new manifolds he is using now and I have to say it is a lot better quality than the OBX and Megan manifolds.

 

The flange Is a T4 type, it wasn't quite flat at the turbo flange though, 30 seconds on the belt sander flattened it right out. OBX has come a long way in their build quality, the only issue that I really had was one of the waste gate bolt holes needed a bit of reeming, it wasn't quite right. Fitment of the turbo was a bitch. It's not OBX's fault though, my hotside is pretty big so it actually came in contact with the LIM. I solved this by spacing the turbo with 2 1/2" T4 flanges welded together.

Reliability mostly, and it's much nicer to have 3 vacuum lines rather than like 18 with my parallel twins. The side effects of this is are a better looking engine bay, lower under hood temps and lower engine temps. Stainless is always going to be better than cast iron for dispersing heat, so it sucks the heat right out of the block.

There is definitely something to be said for high end manifolds. But for now this setup should do me fine. If this manifold lasts me a year I'll be happy, but I think it will last better than that after my re-enforcements.

 

My main problems were the flanges. Even with machining then and separating the engine side I still have leaking from the manifold. I even tried Remflex gaskets and they blew out from the flanges being so off. If you are able to get the flanges to seal and you added some support I can't see you having any other issues, especially since your turbo isn't crazy big and heavy. You should be fine.

 

Well, I can't tell how they are sealing, but I know for sure the mating surfaces on the manifold are true. That's not to say it won't warp when it gets hot, but we'll see.

 

that housing looks really huge on a turbo that small

 

Yeah, it's a 1.15 AR divided hotside, and a .50 AR cold side. Hopefully it will keep me out of boost under light throttle.

 

hopefully it will spool quick enough for you

 

It should spool fast from about 4000rpm. I don't want it to go into boost while driving around normally.

 

um..a new bnr stage 4 turbo for a series 5 rx7 would have done the same job, but cheaper and it would have bolted right up with the series 5 manifold.

 

Cheaper than a $220 shipped Turbo and a $40 second hand diesel center section?

The S5 manifold is a big piece of cast iron, something that I got rid of the twins to stay away from. Not to mention it would be a major flow restriction on my ported exhaust.

 

Did you get your diesel center section rebuilt? I am doing a similar type project using a diesel borg warner s200. I sent it out to have an upgraded wheel put in and I was told I should replace the seals since they won't hold up to a gasoline engine's heat. We will see how it all works when I get it tuned next month.

 

No I actually didn't the truck has 122,000 km on it, so it's probably in pretty good shape. I'm not going to be using this turbo for long though. I'll be upgrading to a bigger more efficient turbo if I keep the car for any length of time.

 

^What brand turbo is that? You never mention it or I missed it..if it's generic Ebay brand like OBX, it WILL fail. From what I've found obx exhaust stuff isn't THAT bad, but does fail after awhile. But their turbos have a 99% fail rate. You could have spent another $100 and got a quality turbo. I picked up a Holset turbo for $500 shipped, but it was a larger one. I'm sure you could have found one in the $350 range..and they're quality turbos.

 

It wont fail because it has a good strong center housing/blades. Not sure if you read that but I've stated that a few times. I'm only using the Ebay hot and cold side housings. The turbo cost 220 shipped and the diesel centre housing was 40 bucks. so i saved 80 bucks at least.

 

Here's some photos of the car in running condition, shes in for down pipe fab at the moment. She needs the intercooler still, that should arrive on friday. More pics to come.

 

I support this cheap build. I'd like to see how it turns out and runs.

 

Thanks for the support! I would like to point out that it's not "cheap" it's inexpensive. It costs less than what I would spend on brand name parts (most of which are overbuilt). My setup won't put a heavy demand on the components I'm using. And all the important components that can cause engine failure if they fail are of good quality.

 

looking good man, heaps cleaner than the stock twins!!