Jump to content
HybridZ

Need help with this turbo kit


swe_crazy

Recommended Posts

this is the rayjay turbo kit that was available in the lates 70's and 80's, Iam sure if you do some searching you will find the schematic for the kit. I wouldnt recommend running it your better off using just the manifold turbo and downpipe and use the fuel injected intake and go with MS , nistune or some other ECU. This will be definatly hard to tune.

Link to comment
Share on other sites

Rayjay (drawthrough) turbo kit? First time I have seen most all the parts at once. I'd love to have that unit on my Z. Tuning is realy easy so don't let it bother you. Obviously the parts need a rebuild. Do you have the boost refrenced FPR as well?

I prefer my own blowthrough turbo setup using a Holley carb. If the kit is drawthrough its hard on the compressor side due to the fuel droplets impacting the turbine. Also I've heard of the fuel puddeling up in the housing causing idle issues. However I've never seen one in use so what do I know....

Link to comment
Share on other sites

Tuning is realy easy so don't let it bother you. Obviously the parts need a rebuild.....

 

No offense, dude, but this is NOT your setup, and 'tuning' this is a BEAR! It's nothing as simple as on a Holley when you simply change jets. This setup will require micrometers, hand filing on parts, and HOURS of runs to get a fuel curve somewhat proper.

 

As for drawthroughs being hard on the compressor side due to impingement, quit repeating articles! The Rayjay is a WET TURBO, it was DESIGNED as a drawthrough setup, as almost EVERY system at the time was, they will work about 75,000 miles if you are lucky, and at that time you will be out of bearing and need a bearing replacement. I have put probably three bearing kits in my Rajay over the years, and the wheel is still in balance and looks perfect. And that is after probably 50,000 miles of not only having fuel impinging on the impeller, but large water and water/methanol being sprayed directly into the turbo inlet via a Spearco Water Injection kit. Repeating myths and legends doesn't help anybody, please refrain from it. This system is so far afield from what your setup is, outside of the fact that they both employ turbochargers, so as to be unrelated. Experience in one really has nothing to do with the other, they are that different an animal!

 

The ONLY thing that makes it passable is the thing he's asking about, which is a BOOST RESTRICTION DEVICE (I want to call it an Impco Boost Controller, but I forget the exact name they used back then...) This is what they used in the dark days before watesgates in addition to inlet and exhaust restriction. The Rajay will make 17-22 psi if the exhaust is leaking or low restriction (the muffler plays a part on this system), and the device in question will limit the boost available to the manifold by moving the internal shuttle to restrict flow. If you're muffler or headpipe should rust and fall off, this device will have you going SLAM SLAM SLAM on a compressor surge all the way up to redline once you get into the top of second, or around 3500rpms in third gear under WOT. This is why Rajay replacement center cartridges were doing such brisk business.

 

Without this device, which is the ONLY thing that makes running that small SU workable on this engine. It limits the boost, and thereby the fuel requirements. If this was the original Crown Style kit, you would play hell with a too small main jet and have to blunt-cut the needle in the SU to get enough fuel flow into the engine---and even then you will run short aroudn 15psi, and need anti-detonant to keep the engine together as the boost climbs (unrestricted, remember no wastegate on those AT ALL!) to around 22psi.

 

I can't tell if you have a Z SU, or one from a Jag (2" or larger). The Jag's have a 1.25" main jet which makes fuel delivery less of a problem, but if it's the 0.100" jet from the stock Z SU, you will have issues getting enough fuel through it, even with a variable delivery fuel system that will raise the fuel in the float bowl.

 

My suggestion would be to keep your Dellortos, rework the turbo adapter to put the Rayjay down lower, and get a pressure plenum for them instead. The drivability (especially cold) will be far better. You will find the response of the system will e LOADS better if you rework the turbo adapter to incorporate a wastegate (easily available from E-Bay these days) and run a proper wastegate to limit the RayJay's terminal boost, and then remove that damnable restrictor and put a Crown-Style adapater, or simply make an adapter to blow into where the restrictor formerly was.

 

The RayJay is oversized for the engine, and the boost response is not all that great. It is not uncommon even on WOT that the engine won't make any boost at all in first gear, and you might get some at the top of second gear. By third you will start getting decent boost, and in fourth I will make boost at highway speeds fairly easily. The compressor map on this turbo is pretty horrendous, and ultimately it's really only designed to support between 180 and 200 HP, but then it's at pretty high flows. The technology that had those wheels made was based on stuff done in the 1960's, and there are really much better alternatives.

 

If you are putting together a 'period correct' accessory car, something with all the goodies from some time period like it was frozen in time...this is something to install. It's a nice curio, but there are FAR better ways to accomplish turbocharging a car these days. There is a reason this system was removed from whatever it was installed...

 

Man, I haven't seen one of those damnable boost-restrictor things for 25+ years! It was a horrendous and terrible way to accomplish the goal of boost control. Seriously, unless you are willing to spend some money to get some proper technology to make that system work properly, I'd put it on a shelf and say 'hey look at this cool stuff I got!' That's where most of my Crown and Rajay Stuff is these days. (Shudder) I lived through that stuff when it was NEW, I can't imagine what it will be like trying to get it all working again now that it's got thousands of miles of roadwear on it!

Link to comment
Share on other sites

well no @@## tony. I said I never saw one running. TRY to read ALL of my post. I have seen drawthrough turbos that needed new compressor side turbines. Possibly due to the wrong part used and or some kind of debris killing it. damn.

 

 

Dude you fail i just lost any amount of internet respect i had for you.

 

Drawthrough is the suck A$$ fail turbo system.i have installed 4 of those rayjay junkers on various makes and models. There junk require oodles of tuning time head gasket should be o ringed etc etc there just junk.

Link to comment
Share on other sites

Drawthrough turbo's work great in certian applications however. A good friend of my dad's has a draw through bug running a single side draft dellorto, and makes GREAT power with it. Even more because the draw through setup, with its aluminum manifold between the turbo and carby, creates an intercooling effect, chilling the air/fuel mixture ICE COLD before it gets compressed.

 

The rayjay though...that IS a piece of crap. I can tell just by seeing how the thing looks like it works :/

 

But don't knock on the draw through setup. It does have its place in motoring.

Link to comment
Share on other sites

Frankly, it's easier to replace the SU and put a Holley on it, that's what I did on the second Corsa 180 I bought. The jetting of the drawthrough systems is far easier on a Holley than on an SU due to restricted jet area.

 

I didn't say draw throughs were crap, I commented on someone talking BS and misleading someone looking for pertinent information. Yes, I read the whole post, and on the whole it was something that probably shouldn't have been posted in the first place, it's devoid of factual substance and used 'heard of' examples...

 

Saying a Rajay Turbo and SU Drawthrough setup is 'realy easy to tune' obviously has had, nor done, either.

 

And that was the real point of the opening paragraphs of my first post. I read the whole post, and again, found it misleading to the O.P. Zex, you're new at this and have an attitude about people with years of experience doing this kind of stuff to this specific engine, be open to the possiblity we may know what we are talking about and don't want to blow smoke (of blown headgaskets) up this guy's butt! Where he lives, L-Engine parts are neither cheap, nor plentiful, and if he goes 'boom' from some misguided advice, it will likely be the end of the project for some time.

 

Anything the opening paragraphs was trying to relate my un-sugar coated personal experiences of tuning one of these setups on four different models of cars: Corvair Corsa Turbo, VW Bus, Datsun Z series, and Datsun 510. In EVERY CASE the SU was a PITA to get to work without some sort of ADDITIONAL boost control to limit the boost, or massive additional antidetonant added to the mix (if you were running over the original designed 7psi of boost). (My e-mail addy 'turbotony' was hung on me well before AOL was even a gleam in someone's eye, and before civilians got access to the net that was available then... Hung on me before 'War Games' and before Ted Nugent sung the praises of the BiTurbo in 'Wango Tango'... I lived through these when they were new, and tolerated 'state of the art' then...and gladly discard it now because the 'good old days' really weren't!)

 

The restriction device shown in the photos of the OP limits flow, and therefore HORSEPOWER. Sure, it makes tuning of the fuel curve a bit easier, as you are limited to 7psi of boost...

 

But who want's that? Barely worth the effort, may as well keep the Dellortos and do without crappy boost threshold, terrible lag (truly lag, and you know my penchant for terminology on that point!), and generally a poor alternative to what is out there now.

 

I am probably one of the few remaining people who will defend the choice of a draw-through setup on an L-Series, because I know you can make them work, and work damn well. Of course there will be all sorts of internet experts who read this or read that, and will come right up with the deriguer examples of 'puddling', or 'fuel drop out', or 'cold running problems'---to some extent they may be true. In most cases they're not, and they're simply repeating something to look knowledgable when they havent' any firsthand experiences. The latest iteration of this is guys following diesels and other new technology applications who note blade erosion due to MASSIVE injection of supplements. Not atomized fuel, or even partially atomized fuel from a carburettor, but direct spray of relatively large micronic sized droplets up to and including a steady stream. Sure, I can show you where oil injection nozzles have cut lines in gears... But this is NOT what is happening in these kits. These kits work for tens of thousands of miles with absolutely no blade errosion at all. You are seeing an apple and saying it's an orange. Simply not knowing what application one thing came from and applying what you see towards something you think is similar. Like watching a pushrod engine break a pushrod in an SBC because of a binding rocker arm and then repeating on an OHC Datsun board 'watch out you have your rocker arms clearanced right with that high-lift cam or you will break something!'

 

But telling someone that this system is 'realy easy' to tune is just wrong. Plain wrong.

 

IF the carb is properly jetted with a proper needle and fuel delivery (*BIG IF*) then it will work, and work somewhat decently to the limit of hte boost restrictor. If you are (as I said) looking for something period correct for a showpiece that won't be seriously campaigned, or don't have ANY intention of raising the boost beyond what the STOCK KIT SETUP IS, then this kit may bolt on and run decently well. The impingment of the fuel droplets on the turbine wheel helps keep charge temperatures down, and can actually let you run relatively lean for what you would expect. The kit can get decent fuel mileage teamed with a 3.36 and a 5 speed at highway speeds. If you put water injection (or methanol...) you can run really lean using the anti-detonant and get phenomenal gas mileage, in the low to mid 30's with the four speed, and likely slightly higher with an early five speed.

 

But if you want something that will go beyond 10psi of boost...forget it, this kit ain't it!

 

Addressing the Single Dellorto Draw Through, this is possible on a VW, but on a 2.4 or larger engine, the jetting is hard to get right and the jet area will run short---there is only so much you can flow through a single 45DHLA. Again, having run this route years ago, the single 45DHLA is a good street combo, and if you put on an ITB with a couple of 750CC injectors....WOAH! But really it becomes easier for that effort to simply put a Holley four barrel on it and suck through it thataway. The cooling effect of the fuel going and changing state really lets you run boost levels you would never expect you could run without an intercooler! The more boost you use, the more power you will make, and consequently the more fuel you will need to dump in there, meaning additional cooling for the additional pressure you are running. It's one of the stealth attributes of a Draw-Through. You can run 17-20psi of boost without an intercooler. Now, if you have a properly cammed and ported head that 17-20psi is close to 460-500HP... Without an intercooler showing... Follow me here? That's why the Holley's get the nod from me, the SU's or even a 50mm Weber (55mm for that matter) won't flow the fuel to handle that kind of HP. Under 250HP you can likely do it on a modified jet SU, or with sufficient work on a 45 or 50Weber/DHLA Dell...

 

But the Holley will run to whatever you want. And when people look at it, it's a Holley Draw Through with no intercooler. And everybody who's anybody that has read the bible according to Corky will tell you: "You can't make any big power without an intercooler."

 

Let's try to keep it in the real world here, and not fantasyland. This kit can work within it's limitations, but don't expect much.

 

Frankly, this one would make a nice addition to my 'oddities of the past' shelf in the shed. The biggest drawback of the kit is it's biggest selling point: the boost limiter keeps you from exceeding normal fuel flow from the carb. But you will never make big power with the restrictor in there. It keeps you from blowing, but keeps you from making serious power as well. Catch 22 Yossarian!

Link to comment
Share on other sites

:violin:

 

I will agree with tony up to the point where drawthrough is good lol. I have seen so many of these rayjay setup loose there carbon seal and actually blow up meaning carb flies from under hood and explosion like activity. Back in the day when they where new they made there power. They did not make huge numbers WITHOUT serious knob dicking.

Link to comment
Share on other sites

Yeah, the good old carbon ring...:icon45:

 

Like I said 'there are better ways to go about it today'!:mrgreen:

 

The big ticket in the old days was the interchangability of the Corvair E-Flow turbines into these Rajay housings. The thing to do in the day was to put the early 150HP Turbines with the later Rajay E-Flow Compressors (now, remember guys, 'hybrid turbos' are a new thing!:icon45:) so you got boost at a much lower rpm than the original setup.

 

Problem was, now you could seriously overboost the system, as the boost was controlled through inlet restriction and exhaust restrictions. A leaking exhaust could detonate your engine to death...and in places like the Rust Belt with everybody wrapping their mild steel exhaust pipes with foil and asbestos, that wonderful salt spray would get in there and bake...and work on your exhaust system YEAR ROUND (woo hoo!) so some time in the summer you hit a bump, at WOT, your muffler falls off, and your boost goes from 10psi to 21+psi as you are wondering "why did the car get louder, and what is that racket from the engine?" So you lift...

 

Get out, realize you lost your muffler... walk back a couple hundred yards to go and kick it back to the car where you wrap it in a sweater and stick it in the trunk... and start thinking "hey, man, this thing was REALLY scooting with no muffler on there, but what was that racket?"

 

Soon thereafter you are replacing split jugs, installing case saver stud inserts to hold the heads on better, and waiting forever for shipments from the far away land called "California" where it seems anybody who's anybody in the Car Business has a mail order shop and can ship you something for a price... And such cool things they had there...

 

After 24 years, I gave up mail order, I just moved there to save me the shipping charges. Now gas is astronomical so short of actually taking up residence at MSA or Turbo City I guess shipping is back to being the cheaper alternative.... Maybe I should move back to Michigan and just have it all shipped again! :mrgreen:

 

:burnout:Draw-Throughs have some stealth advantages which I still like. I think the advent of Megasquirt and SU Throttle Bodies will allow something that is period correct in look, and relatively reliable. With an internally wastegated turbo these kind of period systems can look the part and return decent performance.

 

Then again, this is 70's technology. For a later S30 (77,78 on...)Greddy was there in the JDM and HKS had blowthrough plenums that make these early systems jsut pale by comparison.)

 

Really, this is a holdover from 60's designs, and they really only existed from early 70's to mid 70's, after that Hobbs Switches on EFI systems and Turbo Group Fuelers rapidly took over the Z-Turbo Performance scene.

 

Oh yeah, and the Cartech Box of Pops... But there were JDM solutions that were much better. The Cartech had a decent compressor Bypass Valve, Exhaust Manifold, and Turbo...but the plenum...yeech!

Link to comment
Share on other sites

Ok back to the post. Dude dont install that ray jay kit its going to be a head ache your setup LOOKS SICK spend that money on a stroker! or if your really intent on turbo. sell the tripplies and that could offset your value like I said, keep your turbo , downpipe, get a manifold injectors and EFI ( which ever you like search )

 

edit or cross transform that tripple setup . gut them, tap a fuel rail in build plenum box over ooooooo nice

Link to comment
Share on other sites

It's not really a Rayjay kit, that's only the turbo it comes with...

I'm thinking it may be an early BAE or possibly a Janspeed kit out of Holland.

It's not a Crown, for sure.

 

BAE and Janspeed liked those early boost restrictors. Hell, some of the EFI BAE setups used similar things! (Shudder.)

Link to comment
Share on other sites

It's not really a Rayjay kit, that's only the turbo it comes with...

I'm thinking it may be an early BAE or possibly a Janspeed kit out of Holland.

It's not a Crown, for sure.

 

BAE and Janspeed liked those early boost restrictors. Hell, some of the EFI BAE setups used similar things! (Shudder.)

 

Its not a Janspeed kit. Would be fun to know what it is...

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...