1st Gen General Discussion The place for non-technical discussion about 1st Gen RX-7s or if there's no better place for your topic

Holley, Weber, Dellorto, or DCD?

Thread Tools
 
Search this Thread
 
Old Nov 13, 2017 | 03:54 AM
  #1  
1BADRX7's Avatar
Thread Starter
Rotary Enthusiast
Tenured Member: 25 Years
 
Joined: Mar 2001
Posts: 878
Likes: 98
From: somewhere
Holley, Weber, Dellorto, or DCD?

So I'm trying to decide which route to go when I finally buy a car . I like the look and "wow" factor of the weber dcd, but the only other carb I've had some seat time in was a Dellorto on a 13b 4 port and it was fun.

I've tried to read through all the older threads of the DCD and it seems like there's more pros than cons to running that setup. However, the fact that it's not currently being produced anymore worries me for fear that it'll be hard to find parts when I need it and there's not many around. I know there are 12a setups and I read that RE also made for the 13b 4 port. Please correct me if I'm wrong.

What I'm looking for are people who have first had experience with all of the different carbs and can give an unbiased opinion on which setup they prefer and why. Thanks guys!
Reply
Old Nov 13, 2017 | 09:50 AM
  #2  
t_g_farrell's Avatar
Waffles - hmmm good
Tenured Member: 20 Years
Community Favorite
iTrader: (1)
 
Joined: Jul 2004
Posts: 9,250
Likes: 464
From: Lake Wylie, N.C.
Had a Dellorto on my SA since about 1993 until 2015. Its a fun carb and has some downfalls when cornering right hand if I remember right but you can easily learn to drive through that. The only other pitfall is that you loose some top-end but gain more drivability across a wider rpm range. Thats all due to the long wrap around intake RB normally delivered with the kit. Oh and it has to have all the RB modifications, just a plain Dellorto 48 isn't going to work well with a rotary. I now have a hogged out Nikki that has none of these drawbacks and is very driveable from 1200 to +7000 rpm with a really flat torque curve (unverified, butt dyno measurement) and no bogs or cornering issues with fuel delivery. If you think about it, the rotary is designed to be fed by a proper 4 barrell, with the secondaries delivering to the secondary ports. Holleys for sure and other american 4 barrels may not be designed to work well with a rotary due to the wonky vacuum characteristics of the rotary with the intake pulses that come with it.

The weber downdrafts, especially the progressive dual DCDs are another great solution. Weber parts are still easy to get ahold of and this was one of the premier race setups back in the day. I know a couple of guys that run them and swear by them (not at them).
Reply
Old Nov 13, 2017 | 08:53 PM
  #3  
j9fd3s's Avatar
Moderator
Community Builder
Liked
Loved
Community Favorite
iTrader: (3)
 
Joined: Mar 2001
Posts: 31,835
Likes: 3,233
From: https://www2.mazda.com/en/100th/
finding a dual DCD intake might be hard, but weber parts are really easy
Reply
Old Nov 15, 2017 | 05:41 AM
  #4  
1BADRX7's Avatar
Thread Starter
Rotary Enthusiast
Tenured Member: 25 Years
 
Joined: Mar 2001
Posts: 878
Likes: 98
From: somewhere
Originally Posted by t_g_farrell
Had a Dellorto on my SA since about 1993 until 2015. Its a fun carb and has some downfalls when cornering right hand if I remember right but you can easily learn to drive through that. The only other pitfall is that you loose some top-end but gain more drivability across a wider rpm range. Thats all due to the long wrap around intake RB normally delivered with the kit. Oh and it has to have all the RB modifications, just a plain Dellorto 48 isn't going to work well with a rotary. I now have a hogged out Nikki that has none of these drawbacks and is very driveable from 1200 to +7000 rpm with a really flat torque curve (unverified, butt dyno measurement) and no bogs or cornering issues with fuel delivery. If you think about it, the rotary is designed to be fed by a proper 4 barrell, with the secondaries delivering to the secondary ports. Holleys for sure and other american 4 barrels may not be designed to work well with a rotary due to the wonky vacuum characteristics of the rotary with the intake pulses that come with it.

The weber downdrafts, especially the progressive dual DCDs are another great solution. Weber parts are still easy to get ahold of and this was one of the premier race setups back in the day. I know a couple of guys that run them and swear by them (not at them).
I'm glad they're swearing by them and not at them! lol
For the most part the dellorto would be driven on the road so I probably won't have to worry to much about the right hand cornering but it's not a deal breaker.


Originally Posted by j9fd3s
finding a dual DCD intake might be hard, but weber parts are really easy
I know! It is a rare part.
Who sells the weber parts? I've heard of Pierce manifolds but anyone else you know of?
Reply
Old Nov 15, 2017 | 09:29 AM
  #5  
rwatson5651's Avatar
79 w 13B4port
Tenured Member: 20 Years
Liked
iTrader: (5)
 
Joined: Jan 2005
Posts: 1,912
Likes: 62
From: Alabama
Pierce manifold is the go to for the DCD parts.
There is also a guy on eBay that has some of the harder to find parts. He’s in Italy, but ships quick and cheap.
Fortunately they are durable so mostly what you will need are some jets for fine tuning,
Reply
Old Nov 15, 2017 | 09:31 AM
  #6  
rwatson5651's Avatar
79 w 13B4port
Tenured Member: 20 Years
Liked
iTrader: (5)
 
Joined: Jan 2005
Posts: 1,912
Likes: 62
From: Alabama
The challenge is finding a Set.
Reply
Old Nov 15, 2017 | 03:53 PM
  #7  
KansasCityREPU's Avatar
Out In the Barn
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (9)
 
Joined: Mar 2005
Posts: 6,704
Likes: 1,250
From: KC
I have a dual weber 36 Rotary Engineering setup I'm tempted to sell. Carbs, intake, throttle cable.
Reply
Old Nov 16, 2017 | 06:28 AM
  #8  
1BADRX7's Avatar
Thread Starter
Rotary Enthusiast
Tenured Member: 25 Years
 
Joined: Mar 2001
Posts: 878
Likes: 98
From: somewhere
Originally Posted by KansasCityREPU
I have a dual weber 36 Rotary Engineering setup I'm tempted to sell. Carbs, intake, throttle cable.
I'll send you a pm.
Reply
Old Nov 16, 2017 | 12:04 PM
  #9  
RXTbone's Avatar
Senior Member
Tenured Member 15 Years
 
Joined: May 2003
Posts: 576
Likes: 2
From: Kansas
Not sure what you're looking to use the car for - but, I've ran a Weber for about 20K now. Car goes like raging hell all the way to the redline, but - it's an on the gas/off the gas proposition with the carb. Fun to drive, but not too much fun to cruise. My drive is is almost all highway, so it's not too much an issue - but it's not very smooth in town. I've considered a hogged Nikki as a possibly smoother driving alternative...
Reply
Old Nov 19, 2017 | 10:17 AM
  #10  
j9fd3s's Avatar
Moderator
Community Builder
Liked
Loved
Community Favorite
iTrader: (3)
 
Joined: Mar 2001
Posts: 31,835
Likes: 3,233
From: https://www2.mazda.com/en/100th/
Originally Posted by 1BADRX7
Who sells the weber parts? I've heard of Pierce manifolds but anyone else you know of?
Pierce is kind of local to me, so i just buy from them. that guy on ebay (alfa 1750?) is good too.
Reply




All times are GMT -5. The time now is 05:05 PM.