11 replies to this topic

[gryffinwings]

So, I'm throwing this idea out there. I'm considering saving up for dual side draft carb setup, approximated $1500, plus whatever the cost for jets for tuning. I'm considering this as I've heard it's almost impossible to tune the D15A3 engine and I would like to eventually get a better cam, not to mention rid myself of vacuum leak issues that are difficult to find.

 

Now, I'm thinking the main difficulties are going to be in dealing with getting proper fuel pressure to the carbs, which if I recall correctly is approximated 3 psi. Since I have a fuel injected tank, what options do I have? Should I just change out the fuel injected tank for a carb tank? or is there an easier option?

 

Are there any other issues that I might run into?

[WhereIsMyWrench]

I don't have any direct experience with going from FI to Carb but I have a carby car. You could install an external low-pressure electric pump near the tank and get a fuel pressure regulator and set it up for 3 psi. Another option is to use the DX camshaft which would allow you to use the stock DX mechanical fuel pump. The DX camshaft is longer and has an extra lobe that runs the mechanical fuel pump. You'd have to find a DX camshaft though. 

 

Hopefully someone with some experience doing this will chime in.

[rallyxcrx]

I've had webers for a long time, I run fuel pressure at 6 psi as I don't like fuel starvation. Webers are infinitely tunable, this is a blessing and a curse. Dave

[gryffinwings]

I've had webers for a long time, I run fuel pressure at 6 psi as I don't like fuel starvation. Webers are infinitely tunable, this is a blessing and a curse. Dave

 

Extremely tunable is nice, I'm still debating the conversion, which is why I want to know what is involved in the conversion, how did you go about doing it?

[gtpilot]

Get a TWM manifold and a set of DCOE carbs...depending on what your goal is either DCOE 40mm or DCOE 45mm - if you get 45's they are huge and you will need to get a smaller choke in them to get good drive-ability for the street (IMO - we made 185 crank HP with a built 1.3L with 32mm chokes...).  As has been suggested, I would use a electric fuel pump with the right pressure/flow characteristics for carbs - like this - that will probably work with a fuel pressure regulator, I always used 3 PSI for Weber DCOEs.  

 

If you want a manifold I have an old TWM from my racing days of EW motors that I will let go cheap.

[PHAT87CRX]

Isn't a recirculating fuel system with a bypass regulator and a return line to the tank a better set-up than a "dead-head" fuel pressure regulator set-up, even with carbs ?  Some systems like that adjust Fuel Pressure by changing out a fuel return line restricter / jet / pill.

[gryffinwings]

Get a TWM manifold and a set of DCOE carbs...depending on what your goal is either DCOE 40mm or DCOE 45mm - if you get 45's they are huge and you will need to get a smaller choke in them to get good drive-ability for the street (IMO - we made 185 crank HP with a built 1.3L with 32mm chokes...).  As has been suggested, I would use a electric fuel pump with the right pressure/flow characteristics for carbs - like this - that will probably work with a fuel pressure regulator, I always used 3 PSI for Weber DCOEs.  

 

If you want a manifold I have an old TWM from my racing days of EW motors that I will let go cheap.

 

Wow! 185 CHP with a built 1.3L   That's impressive, I'd like to know the details of that build. The goal would likely use DCOE 40s, with 45s I'd have to increase the redline pretty high I think.

 

Anyways I sent you a PM.

[rallyxcrx]

I buy all my carbs, manifolds, air filters, jets, from Pierce Manifolds, Dave

[gryffinwings]

I buy all my carbs, manifolds, air filters, jets, from Pierce Manifolds, Dave

 

That's actually where I found stuff for the 1G CRX Si to do the weber conversion, but it is quite expensive.

[Lateral G's]

There is a seller on eBay right now selling new TWM manifolds for way cheaper than what Peirce has them listed for. Just search "EW Weber" on eBay. I recently bought a TWM manifold from that same seller for my D16A1.

[gtpilot]

There is a seller on eBay right now selling new TWM manifolds for way cheaper than what Peirce has them listed for. Just search "EW Weber" on eBay. I recently bought a TWM manifold from that same seller for my D16A1.

 

Hopefully you didn't buy one of those IMs to fit a D16A1?  The EW has round intake ports...the D16A1 is an oval port?  You did buy the one for the Integra motor?

[Lateral G's]

The eBay seller has 3 different TWM manifolds listed for sale right now. EW, D16A1, and B18. I bought the one for the D16A1.