i may have the option to buy a freshly rebuild streetported 6-port 13b from an 91. if i did this i would run the 91 intake (port matched) with a haltech. ignitiion would be stock s5 coils and one msd 6a.

my other option is to rebuild my 78 mild streetported 4-port 13b (rx-4 style). if i did this , i would enlarge the ports a bit more, and then let it breath through a weber 48 ida. it would run with 2 msd 6a's and 3 blaster 2 coils.

both would run with a rb dual exhaust (headers, dual pre-silencers, collecting right before the muffler).

any recomendations on which to go with? (your reasons would be nice as well)

 

4 port and the carb will be cheaper, more powerfull and look cooler in my.

4 port make more power as you can port them bigger and 2nd gen NA motors have a diffuser in the exhaust port that makes them near imposible to port

 

i think that the 91 with efi would be able to get me better gas milage. as for power, i figured that i could get about the same on them. i am shooting for around 200 to the wheels (but not expecting any more than that).

can you take the defuser out?
(i would also get pineapple racing's six port sleeves if i went that route)

 

6port EFI - dont know really what you can put out of a

6port. With Haltech and Ignition you can still run a direct fire system can't you?

This setup will be costly! Remember you gotta get dyno time to tune it properly and thats $$$. Although once your done your be set. Dont know about the Pineapple sleves thought. I personally dont belive in them, theres only so much that you can get from a 6 port.

4 port IDA - Like my buddy 82 said it WILL LOOK alot

cooler and will sound a whole lot meaner but you'll be pushing all the power you can get out of it rather that the 6 port. As you know you'll be needing dyno time if you decide to go turbo IF you have the paitence to put it together. Remember also, the down falls of a carb gas milage, tuning, weather, ect...

either way I think you'll be spending more with EFI because of the Haltech and tuning it. But once its done your done. Look at Rene from Rene's muffler shop he gave up on carb and went to EFI/Fuel Management 8's.

But thats a whole different story running straight alcohol.



Ryan

 

It depends what you want to use the car for. For everyday driveability go with the 6 port EFI.

If its just going to be a fun car, go with the four port, because four port motors can be ported much farther than a 6 port. With a 6 port at most you can only get a very small street port out of them.

I have the S5 setup myself (89-91), and its a very nice setup. VDI makes the car much more fun.

 

my seven is a daily driver (or i guess i should say was. i just blew an oil seal a couple days ago, and thus why i need to decide and do the swap soon).

i did like the 4-port when i was running it, but on the other side i donot have a good feel for the 6-port motor setup, because the se motor that i am running with right now has always been a piece of ****.. it has high miles, was set up horribly with a carb to small. (by the way, if you ever run into a guy named chirs in oaklahoma who owns e-specialtycars, burn down his shop for me.. he is an incompotant jack ***, but i am not drunk enough right now to go into that story.)

one more piece of information : the 4-port motor that i have is 9.2:1 while the 91 6-port is 9.7:1 compression.

 

Well, if your running an SE motor with a carb, my bet is that the 6 ports were probably wired open in the process. Most if not all aftermarket carb manifolds have nothing to acutate the 6 ports.

Anyway with the 6 ports wired open, your going to have **** for low end power. In general a carbed 6 port, in my opinion, it not a very good idea for exactly that reason.

My S5 6 port has plenty of power, trust me.

Oh yeah, about those rotors. You can swap back and forth any series of 13b rotors into any 13b engine.

 

I like 6 Ports. But if you're going to do all that EFi and Haltech trouble for an N/A application - then forget it.

Go with the Old Skool 4 Port.= and a Carb. Much simpler, for about the same power.

 

i like the 4 port. simpler cheaper raw power, and a way better startign point if you want to turbo

 

I would save for forced induction otherwise....4port

 

The 4 port is a good start for forced induction.It comes wiht the lower comp rotors