Datsun Roadster Forum-311s.org

Hi Minh , I have e-mailed you 3 photos of the modified MR2 blower in my 2000


Dellortos should work well in a blow through turbo / supercharged setup too .. Lotus used them on their Esprit turbo

Would anyone know. Since the 40 Webers fit the the Solex manifold, would the 45's fit as well? Or, are they bigger than the 40's?

Yes the 45s will fit on the solex manifold. I think a set of 50s will fit as well.
Will

Steve...

Can you chalk up another part for the parts interchangeability... Weber or Dellorto 45 are be physically interchangible with the Solex 44.


Okay, decision time (these are estimates)

$250 Supercharger
$ 50 Intercooler
$300 45mm Weber/Dellorto DCOE (2x)
$ 75 Manifold (custom built)
$ 80 High pressure fuel pump
$ ? B-cam or grinded stock cam
$ 50 high flowing cone filter
$ 70 piping, mounting, screws, what not, etc....
---------
$880+ Lets just say almost $1000.

$200 Turbo
$ 50 Intercooler
$300 45mm Weber/Dellorto DCOE (2x)
$ 75 Manifold (custom built)
$ 80 High pressure fuel pump
$ ? B-cam or grinded stock cam
$ 50 High flowing cone filter
$ 60 piping, mounting, screws, what, etc...
---------
$820+ Lets just say again almost $1000


Plasmaboy how does haul now with 40mm DCOEs. How noticibly different is from the a stock U20: 0-60mph, 1/4 mile, heat? Are we looking at 250+HP? Maybe 300HP?

Cost is about the same for Turbo, Supercharger, and any engine swap.

Reliability on readily affordable parts are leaning towards an engine swap.

Author Fonzarily Cool is the suped up 2000 by virtue of trueness, rarity, finess, just about as much power can pulled from this little U20 outside of adding NOS. Raising the qustion would Datsun and BRE would gone this route?

Yet, $1500 in parts for everytime the timingchain goes is anoying.

If I was single & living on my current salary, I'd supe it.

However, being a a head of the house I need to be prudent. I will and always be jelous of the guy who have suped it up. This lot in life I choose.

I'm gonna swap.

Thanks everyone

PS: 40mm Weber/Dellorto go for less than $150. Food for thought for you R16 owners. If I gonna suffer I want people to suffer with me

On EBay I can acquire a turbo for less than $100 and an intercooler for $25...

That would bring the cost of the setup close to $650+.

Ah jeez here I go again!!!

Well I gues I will have to keep an eye out for any other deals.

I gave Mike Kerr a visit yeserday to get some gaskets and a lower radiator hose...

The Turbo mystery has been revealed to me!!!!!

What Mike did back in 1977 with his 2000 was this.

1. Create a new intake and exhaust manifold that place the turbo right where the dual carbs located.

2. He re-routed the outgoing exhaust through the a new hole in fender wall in front of the cluth master, going back down to the muffler. This way the steering column remains intact.

3. He then took 1 of the original 2 SU carbs out and made the remaining 1 into double float. Therefore twice as much fuel and only 1 carb to adjust.

4. He routed the oil from the block's oil plugs to and from the turbo.

5. Added a 2nd overflow tank next to the old one and routed the water to the intake as a water mist intercooler to control boost temperature.

6. Installed a K&N mushroom filter on the SU carb that is attached to the turbo in between the overflow and the turbo.

He runs his system at 15-16 Boost Pressure and 7 without water still spinning wheels in 3rd gear.

He said:
1. This mod done wayback then

2. Thinking now the newer turbos are whole lot better. An intercooler would be more convenient.

3. A pressurized oil resvoir trap connected to the ignition relay would keep the turbo lubricated at startup.

4. A delayed ignition kill for about 60-30 seconds to keep the motor running would help maintain the turbo

5. I suggested if a water cooled turbo replacing the stock water pump with an inline electric water pump would be better for 60-30 seconds than keeping the motor running would be better. He said yeah that would be cool too.

This means without the need of Webers at all now the cost is would be about... $350+ !!!

Oh, I forgot to mention something else.

Boring out to 12:1 compression and turboed is operational with U20.

At 12:1 compression, you will blow the head to mars with a turbo. I don't know about you but I would go the other direction and lower it to 8 or 8.5: 1 If you run a turbo. The U20 is a great motor, but the head is both its strong point and its weakest link. They are not cheap to replace either.

Just my $.02

Will

With the supercharger on my car , and the head having been shaved 0.7mm over the years .. I got a 3mm copper headgasket made to replace the original .. compression is around 8 - 8.2 : 1 with 15 psi boost

I double checked memory... I got the facts crossed on the compression. It's wrong.

The 12:1 was for the 12:1 stock carbed car NEXT to the turboed one. The turbo's compression is 8-8.5.

I hope I didn't lead some poor guy astray.

Thanks for setting my hubcaps straight fellas...

With 12.5:1 you still can't run pump gas. My compression is close to 10:1 and it doesn't like anything but premium, I had considered trying higher compression but after putting the engine back together I think I will keep it where it is.

Will

I just realized something...

If I opt to turbo, I really won't need my Flowmaster (muffler) anymore. All I'll need is a tip. I can get at least $40 for the new Flowmaster.

Not to mention only 1 rebuild kit for my SU.

Hi Minh .. from your description , it sounds like you were going to use just 1 of the original SU carbies in a draw through turbo ? If that’s correct .. I’m sure just of these small carbies would cause a massive restriction to the breathing of the turbo / engine . This is one way of restricting boost to the engine .. but it’s a very bad way to go about it and you would lose a lot of the potential power from the turbo instillation by choking the engine . It could even cause such a restriction that the vacuum it would generate between the carby and turbo may end up sucking oil through the turbo ‘s seals into the intake and or damage the turbo ..

Hi Minh .. the last post was from Plasmaboy .. I forgot to log in before posting

I don't think the carb will meter fuel correctly, either. I'm not familiar with how a turbo setup operates without fuel injection?!

An SU meters fuel through the veturi effect in the primary chamber, this means the air rushing past creates a small vacuum that sucks fuel through the jet/needle gap. Add positive pressure instead of the always present vacuum in a normally aspirated car and the fuel flow will drop off dramatically. It may even push the fuel back into the float chamber since the pressure can be higher than the venturi vacuum. This is all assuming the carb is after the turbo. Maybe they are placed before? Like I said, I have never seen a carb setup turbo...What happens to the fuel charge when it is compressed prior to reaching the cylinder? Fuel droplets in the plumbing? I would guess that a bigger carb with seperate low and high end jetting would be required to get the setup running well...

An EFI turbo motor requires very high fuel pressure to push the fuel into the intake during + pressures...

A lot of engineering goes into building a turbocharged motor, the manuafacturers have bunches of engineers who know a whole lot about cars...I think building a setup would be a very steep learning curve...TR