TheSamba.com :: View topic - 1974 Standard Beetle with original Rajay turbocharger kit

Sat Jul 31, 2021 2:44 pm

The Rajay turbos were probably state of the art in that time. I was only 14 in 74 so I didn't see much for turbos and the big diesels were mostly Detroits which at that time had a SuperCharger on them.
When I was about 18 my Dad bought a turboed Tractor. It added 8 hp to a 72 hp N/A Diesel engine. It was an English Leland 272.
We worked the crap out of that tractor.......

I am interested in most any turbo setup but practicality is the most important due to not being able to justify a car that can't be driven most anytime.

I've got a quite a bit of mileage under my belt using turbos and have run a lot of different combos in the quest for more hp but reliablity has always been the most important.
A lot of improvements have been made like ignition control and intercooler technology so that gain of 50% on probably 8 lbs is realistic.

For comparison to now my 1679 put out 112 whp at 6.0 lbs of boost 3 1/2 years ago. That would equate to around 128 crank hp.

If the owner wanted a little more current drivability there are a couple things he could do......for one a CB black box would adjust his boost timing for help if detonation was a problem and it wouldn't even be noticeable.

That would be a fun little car if he wanted to make it more than a show car.......but that's just me..
It's a beautiful car and kudos to him for keeping it that way.......I just couldn't do it.

Wed Aug 04, 2021 5:32 am

That car with it's turbo kit is a perfect representation of the state of the art in street drivable turbos in the early 70's. That is exactly where it was at. In fact for a low cost, low boost daily driver there is not a lot of room to improve it. There is no doubt in my mind that that car runs and likely runs very well.

Could it be improved with today's technology? Of course it could! Starting with the ignition, I highly suspect it is running a "locked at 24*" mechanical distributor (which by the way IS the present state of the art for many today, just ask on this forum) you could gain a couple HP, a few MPG and some drivability with crank trigger. Then there is FI and an intercooler but realistically none of that was done in those days on a street conversion.

As for dependability, my Rajay ran daily in our only family car for about 5 years, in +90* to -40*F weather. Rajay still has a positive reputation in the aircraft industry so they are not junk!

Wed Aug 04, 2021 8:42 pm

oprn wrote: That car with it's turbo kit is a perfect representation of the state of the art in street drivable turbos in the early 70's. That is exactly where it was at. In fact for a low cost, low boost daily driver there is not a lot of room to improve it. There is no doubt in my mind that that car runs and likely runs very well.

Could it be improved with today's technology? Of course it could! Starting with the ignition, I highly suspect it is running a "locked at 24*" mechanical distributor (which by the way IS the present state of the art for many today, just ask on this forum) you could gain a couple HP, a few MPG and some drivability with crank trigger. Then there is FI and an intercooler but realistically none of that was done in those days on a street conversion.

As for dependability, my Rajay ran daily in our only family car for about 5 years, in +90* to -40*F weather. Rajay still has a positive reputation in the aircraft industry so they are not junk!

I'm not sure what a Rajay powered airplane or a watercooled Rabbit with same turbo would have in common with an aircooled Vw but if you want to make the stretch..........
A simple search on Rajay Reliability will bring up plenty of dirt on the airplane failures for that turbo......
For Ex.......a 1975 Senenca II turbo going through 3 turbos in 1200 hrs. with 4th failure in 700 hrs.
Also...an airplane used a turbo for maintaining power to altitude....not adding boost at sea level. Boosting at sea level would usually blow the engine shortly after takeoff.

As for the 74 Beetle.....it's a Fat Chick....most VW aficionados wouldn't give it a second look due to it's newer body style. Most VW addicts would also scoff at the turbo so the only enjoyment the owner could really get would be to drive it and blow the stroker's guys doors off........Obviously...at 11,000 miles in 47 years......that didn't happen.......so if it was sooo much fun to drive......why would it not be higher mileage........just askin........

I drive my buggy every chance I get......Not because it's purty or an attention getter, although I do get lots of thumbs up and compliments even though its just a driver........But because it is such an enjoyable car to drive and it goes like stink.........plus it's more reliable than a stock Volkswagen because it has all the modern upgrades like EFI, Turbo and CrankFire ignition.
The average VW guy doesn't even bother looking at it which is just fine with me......but kids and parents love it especially when I let them sit in it even though the kids have wet swimming trunks on.......

Thu Aug 05, 2021 4:17 am

With all due respect Clonebug, how an owner chooses to use his car reflects nothing about it's reliability. Also the turbo itself has no idea what engine it is on... that is a pretty weak argument. I would be more than happy to own that Beetle and trust me it would get driven all over Hell's 1/2 acre and back... after I changed it to crank trigger... :wink: and maybe a 40 DCOE progressive conversion... would like to try one... :D

I love the fact that you actually USE your car. That has led to all the refinements you have made but remember that most of those improvements are a result of you cashing in on the developments that have happened in the 47 years SINCE that Beetle was put together so it is more than a bit unfair to make the comparison.

Mon Jun 06, 2022 8:54 am

Hi everyone, was super cool to stumble across this discussion and the kind words about my late father's favorite child... this 74 Beetle. I am doing my best to take good care of her and keep the mileage down, but she is fun as hell to drive. Most of her pep is really noticeable in 3rd and 4th from mid rpm's up and does seem to pull around 8lbs of boost (I have never pushed past it in fear of something bad happening!)

Speaking of boost, while recently going through some of my father's files, I came across a bunch of vintage VW mags (still haven't found his old stash of National Lampoon's though) and these original Rajay Intsructions and Schematics. Figured you may be as geeked out on these as I was.

Enjoy - Mike

Mon Jun 06, 2022 9:34 am

Man, if you ever get a chance to scan those in for the archives here that would be a way cool set of history to document right there!

Mon Jun 06, 2022 10:11 am

Thanks for that!

Mon Jun 06, 2022 10:29 am

I really doubt that they produced 110-120hp with 8psi boost. Most likely 80-90hp with stock internals and without water injection.

For comparison Saab 99 / 900 watercooled engine had 100hp with single carb and turbocharged+fuel injected version did have 145hp with 12psi boost with knock sensor.

Mon Jun 06, 2022 1:50 pm

clonebug wrote: For comparison to now my 1679 put out 112 whp at 6.0 lbs of boost 3 1/2 years ago. That would equate to around 128 crank hp.
Every engine responds differently. Remember that the air cooled VW engine with it's center mounted single carb is known to be very poor in the breathing department. A turbo completely eliminates that breathing problem so yes it's entirely possible the the % gain over stock is larger than an another engine design. The % gain/psi increase is not necessarily a linear thing across all engine types and designs.

Mon Jun 06, 2022 8:11 pm

-Alex77- wrote: I really doubt that they produced 110-120hp with 8psi boost. Most likely 80-90hp with stock internals and without water injection.

For comparison Saab 99 / 900 watercooled engine had 100hp with single carb and turbocharged+fuel injected version did have 145hp with 12psi boost with knock sensor.

Using my favorite Boost/Airflow Calculator I get 120 cr. hp at 4500 rpm and 8.1 lbs boost.
That is from 97 CI. and 100 degree intake temps which might or might not be true with a drawthru since I've never seen one that logs IAT's. I'm just guessing that the fuel will cool the intake to the 100 degree temp.
Standard boost numbers of 8.0 lbs. would give you 150*F with an ambient temp of 80* F. without intercooling so the Venturi effect would have to be working pretty good to take out 50 degrees.
With intake temps of 150* F and staying at 8 lbs. you would see 110 cr. hp.
So you lose 10 hp with a 50 degree increase of air temp.

Thu Oct 27, 2022 12:32 pm

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Thu Oct 27, 2022 4:30 pm

Another interesting survivor.

Fri Oct 28, 2022 6:28 am

Here is some info on them in a Clymer manual from 1973 I have, they also talk about the Schwitzer turbo set up, but it required a modified deck lid, and is a blow thru the carb format.

Sat Oct 29, 2022 11:36 am

Nice!

Wed Nov 02, 2022 4:33 am

marro843 wrote: Hi everyone, was super cool to stumble across this discussion and the kind words about my late father's favorite child... this 74 Beetle.

Here's something you probably didn't know. Your father converted the engine from an alternator to a generator. According to the spec sheet, the kit didn't clear the alternator.

Thu Nov 03, 2022 8:45 pm

Here's my 1969 Bug back in 1981. What a blast that Turbo kit was. Easy to install, started right up and ran great! At night the headers would glow red after a hard run on the highway.

Fri Nov 04, 2022 4:35 am

It was a great way to make power at a decent price. Too bad the company did not continue to grow and offer more and better products. Ahead of its time perhaps like so many others in the past. Maybe the public was just not ready for turbos yet.

Fri Nov 04, 2022 9:20 am

I'm sure it would be a fun driver but as with any thing that adds power.....you still have the addiction factor and turning it up beyond it's limit will introduce problems.
I'm sure some drove great....but others probably blew the crap out of their engine.

A 20 something kid more than likely flogged the crap out of the poor thing......Us elder adults are much more responsible and can refrain from beating it to death....... :wink: :roll: :lol:

Fri Nov 04, 2022 5:00 pm

Impossible to make anything idiot proof! The guy that ran his turbo Beetle past it’s limits then is the same guy that will do it today.

Tue Nov 08, 2022 4:46 am

While everyone's looking at the cool turbo kit... I'm looking at the mint Continental bias ply spare! :) I wish someone would repro those!