Datsun Roadster Forum-311s.org

Being a proud owner of a 67 1600 roadster, I come to this site several times a week to do research on my current vehicle as well as read the commentary / cheerful banter about a variety of topics. I can't tell you folks enough how much I appreciate your valuable insight. After a long freeway drive with a 4spd I started dreaming of an extra gear to calm down the engine a little bit. During my transmission swap research, I've recently become very interested in this SR20 engine swap that many of you speak highly of. But now I'm starting to see a few more threads about the SR20DET swaps. I've always been a fan of turbos and I love big power.. but I have to wonder how streetable the DETs are in these little roadsters. It would seem to me that an accidental goose of the throttle would pitch these cars sideways and instantly out of control. The beauty of these these cars is the handling but I won't lie, i'd love to have a few more ponies under the hood. I'd love to hear some insight on how these SR20DET motors fair in these cars. Seems to be on paper that it just might be over kill and that you'd never get a chance to stick to the pavment. Any of your turbo heads wish you would have just went the SR20DE route? Or the opposite, do you any of SR20DE guys wish you would have forked out the extra loot to go the turbo route? I have to admit, watching that video that Alvin posted on youtube about Kevin Desirello's roadster seems like a blast.

Any thoughts out there?

Jesse

My thoughts, as I have had many sleepless nights on this matter!

-I kick myself for not going the turbo route initially
-I then realize that a turbo in a 2000lb car would bring me that much closer to wrapping my baby around a telephone poll, so I say no to turbo in roadster. NO!
-Once you go turbo, you can't go back to NA
-The feeling/sound of boost is addictive. Having it in a roadster is tempting
-A stock boosted SR20DET or KA-T in the roadster is extremely streetable, ie. there's tire smoking power whenever you need it, but within the realm of "safe"
-It is very fun to haze the tires from a roll in 2nd gear at 40mph and stay squirelly until you grab 3rd at 60mph!!
-Anything past 200hp with these turbo'd engines(easily acheived) can get you into trouble with stock brakes/rear end/suspension
-If you want a few more ponies under the hood just pump up your stock motor

Kevin's car had significant drivetrain upgrades to handle the power like big disc brakes, a Ford rear end, etc., but I can't imagine running that car on a road course with the boost creeping up on you mid corner and no weight on the rear...yikes.
It reminds me of my friend's 400hp SR-powered 510: good for lighting the tires up in any gear but a handful to keep on the track.

Totally depends on your budget and your desires.

The easier way is to attach a 5spd to your R16 and call it good. Or another stupid easy swap is the U20. A U20 with a 5spd requires a radiator, a driveshaft and a different transmission mount. You might need to open up the transmission tunnel a little to get the shifter through but thats about it.
As for running a turbo on a roadster, I have traction issues with the power I have. As is I could really use a 215 tire in the rear, however thats not going to happen without some serious body work. I can light up a set of 195/55/14 race slicks all day long even with a LSD rear end. I would be scared to run a 300+ hp roadster on 195s as I know how tail happy mine is with its current amount of power. I've been contemplating building a bigger U20, but I don't know if I really want the power as I can't use what I already have to its fullest extent.

Just a thought

Will

Any of your turbo heads wish you would have just went the SR20DE route? Or the opposite, do you any of SR20DE guys wish you would have forked out the extra loot to go the turbo route

I have built cars with both engines and both are very tractable. A lot of guys think that just because they put a SR20DET into their car, it will become un-drivable or some sort of crazy handful-- this could not be further from the truth.

The base S13 SR20DET makes 205hp, and at that hp level, you can drive the car as fast or as slow as you want with no drivability issues. Want less power? Just don't dip into the throttle so much. Mom could drive a SR20DET powered roadster and do just fine.

The beauty of the SR20DET is you can make it as much or as little as you want it to be. You want 400 crazy-car-breaking HP? No problem, easily done. You want something mild that makes a little more power than most cars, then leave it stock-- you can have it any way that you want.

Just remember you are dealing with a light weight car with old steering and suspension and a rear end that won't take too much abuse...

The other thing to keep in mind is the amount of work that the turbo engine swap adds. I like to say double the work for a turbo engine (by the time you have built the intercooler plumbing, larger exhaust modifications, built a turbo manifold, etc.)

So as I have said many times before, consider all your resources before taking on the swap. Do you have the time, money, fabrication skills, etc. to take on such as swap. A DET swap is not a weekend (or month) project!

As for my personal car? I am putting a S15 SR20DE into it-- 165hp stock, plenty of power for the chassis, and in the over all scheme of things much easier than the SR20DET swap.

Well, that is my .02Â¥, spend at will...

Michael Spreadbury
spriso motorsports

Will and Michael’s comments are right on and very good!

I think a lot of us have at one time gone down this road.

In the past I have built a 1600 turbo motor with 5 speed that I really liked. It was huge project for the power gains. I went back to a ’66 1600 for years and totally happy (I LOVE the 1600 in town – a hoot!) until the power bug got me again.

I set out to build a custom Roadster with a Buick GN 3.8 turbo motor/T5 trans. This project got way too time consuming and now sits. Like Michael said – really think about a big project – it will take twice as long and double the money you think.

I really like the ’66 the way it is so an engine swap was out of the question. So, I lucked up on a 67 2000. Like Will said, the 2L/5 speed is a perfect match for the Roadster. Plenty of power and a good cruising gear. I would drive a good running 2L Roadster then make up your mind. Again – as Will said – a 2L/5 speed instillation is a day project.

Now that being said - - if my wife would let me have some money - - I would have a SR20DET built by Michael! They are so well done!

My thoughts
First,
Swap a 5 speed into your 1600...easy project … maybe add a H20 type bottom end to increase your power...not much more work.
Now you have a great car to drive.......

Optional,
Find another car for a SR20 swap and start collecting parts....
Remember "A DET swap is not a weekend (or month) project!�

OR

Have Michael do it.....


My 2 cents

67.5 SPL311 FJ20E
69 SRL311 FJ20ET Project (5 years old and growing) LOL

fj20spl311 wrote:My thoughts
First,
Swap a 5 speed into your 1600...easy project …

Which 5 speed? And does that involve a new drive shaft? You can fit some big honkin' trannies into an MGB (because of that huge, heavy 4 speed they use), but the tunnel on the roadster is a bit more petite, I think.

Are there any modern 5 speeds that swap in? Does anyone sell an adaptor plate?

The roadster 5 spd is the best shifting transmission I have ever used. I have never found a smoother shifting one. Infact most of the modern ones feel like crap. They are notchy clunky and just not that nice to shift. A miata has a super short throw for the lever, but the thing is notchy and not very smooth. The roadster one however shifts like butter. My Alfa has a transmission that is widely viewed as being the smoothest shifting transmission of the era has nothing on the roadster one even though its likely nearly the same creature inside. Its still a Porsche designed steel syncro setup but its just not as smooth as the roadster one and the throws are sooooo long.

After killing a number of them you would think I hate them, however I don't. Its still the best shifting transmission I have ever worked with. I don't so much like the later Warner boxes, they are notchy (in my opinion) but still not that bad.

Will

the 5 spd from a 2000. I don't think any other tranny fits easily.

A diesel front case and later 5 speed guts/rear case work. Search for Daryl's write up. A very creative solution!

The 2000 box is easier though...

who am I kidding...I'll have turbo with a side of boost please!
someone help fund the madness
Jesse take the plunge and boost

Any stock roadster can light up tires by cranking the steering wheel and flooring it...stepping on it in a straight line and trying to keep it straight is priceless!! only boost can do this
ROb' SR20DET

Alvin wrote: only boost can do this
ROb' SR20DET

I could do that with my normally aspirated Mustang with an open rear end...

no you can't

BTDT. It was a pretty hot small block in a stock coupe. I got both rear tires spinning on fresh asphalt. I can't do it anymore though. I sold the car.

I could set the brake on the Echo and drag the back wheels. That would leave a mark