I was wondering what everyones ideas were on carbing my 1985 RX-7 GS (12A carb.). My mods are listed below and I am thinking of adding a new carb to my system. I have heard about the Weber, Holley, etc. but which one is best for my situation? Also, are Webers 4 barrell?

I want it streetable , but I want some more power too.

The supercharger and turbocharger setups I was discussing before are not going to work out. I just don't have the time, but maybe down the road I will get some!

Anyways, your imput would be great. Thanks.

 

holley is 4 barrel, weber is not.

 

if you're looking for streetable power and you want it very cheap, do a search on mechanical secondaries.

Do that mod to your Nikki, and you will be very happy. At least until you have the money to upgrade to turbo.

Here's my philosophy- Modify what you have to the best of your ability for as little money as possible until you can afford your dreams (turbo/supercharger). Rather than spending money on a weber, save it, and keep saving until you have the cash for a turbo. You will be much happier in the long run instead of putting small amounts of money down now that end up being just as much as the turbo later. This philosophy has worked for me, and I hope it does for you and others. I'm speaking from experience, as I've done both options with cars. (little parts now/saving for big part)

 

i agree with MR, but if you were going to decide between Holley or Webber, for the street defenetly Webber is better especially if it's a side draft, as for racing i go with Holley.

 

true, very true

 

8v6? us Nikki guys are losing..............

 

Yeah, on a system without a port, or even with a mild port, a modded nikki is fine. Why spend huge $$ on a weber unless you're planning to street/bridge it?

Jon

 

I voted modded Nikki because of the smog ***** in TX that still put 1978 and up cars to the sniffer...

 

Yeah, in that case, modded nikki with a new high-flow cat installed on that RB exhaust...

And don't even THINK of removing the rats nest!

But you can still get great performance out of that, and with the other street cars smogged too, you'll beat the pants off 'em.

Jon

 

To let everyone know, emmisions are not an issue. Also, how can I modify my Nikki? Does this mean to convert to mechanical secondaries?

 

Thats one mod. Search for sterlings writeup.

 

If your secondaries are already working properly, then making them mechanical will not give you anymore top end power. Whether they are vacuum or mechanical they will still open to the same size at WOT. What it will do is give you some more mid-range power, since you will now choose when the secondaries open.

 

Nikki would work fine,and cost the least of the choices.
You should also fit a Carter/Holley fuel pump & FPR to supply the modified Nikki with fuel.

Very decent hp figures are possible with the Nikki.
The pic shows a comparison between a stock & modified Nikki by Paul Yaw.

 

The Yaw power figures look unusual. The results are what i would expect from a modified carb and improved exhaust set-up. However the stock data does not line up with anything I have seen.

 

From what little I've heard Yaw is the best.

 

http://personal.riverusers.com/~yawpower/

 

BrewerBob- I am not saying that Yaw is not good, but that his data posted by karism is highly suspect. The data is stock carb 142.7hp at 7,000rpm and 142.5hp at 8,000rpm.

As I said in my post the figures for the modified look right- its similar to what I am getting from a 12A engine with a bored out/rejetted Nkki and other bolt-on/bolt-off modifications. Its the stock data which needs explanation.

If you take it as both sets of data are for the same engine with modifications, then the impact of a Yaw modified carb is to increase power by 9hp above that from the stock carb.

 

I believe its a stock carb on a modded motor with header exh I bet.

 

How much horse power increase will a new carb such as a holley or weber add. How much more could you get with a port?

 

The comparison is between a stock and modified Nikki.
The engine however isnt stock,and includes a header if i remeber correctley

 

I'm not agruing. I have absolutely no idea. It may be that Yaw is the best stock. I don't know if IT rules allow carb changes or not and whether the guy that told me about Yaw was using hte rules to base his comment.

 

I would tell you to get a holley 600. that is what I have. I spent $150 on the carb new got a metering block for $50 to adjust the secondary jets. you would also need a Racing Beat intake, which is pricey. Iam currently running a stock port 12a and is a hell of alot better than the stock carb! But if you are looking for real power you MUST port! I have heard, that the holley gets better gas milage because of the 4 barrels on the street?

 

Define pricey.

While it is going to stay street legal it only needs to be SC street legal. The damn thing can be missing doors and putting enough smoke out to kill a buzzard nut it's still legal in SC. So, I'm not too worried about gas mileage. It is to be an autox/track car. Just not a trailer queen.

 

i say go with a webber. the holley 600 is also good. but if your going for street use the holley 600 vacume secondaries are a little better on gas and more reponsive then the double pumper.

 

RacinBeat.com

Check it out, you can see any price you want. Holley or Webber and intakes for both.