im debating with myself on the pro's and cons of converting a gsl-se efi setup to carbs, and i figured id ask for some expert advice. my car runs fine with the fuel injection system, but ive heard that the gsl-se injection system is too restrictive and inefficient, and i certainly think the motor has more power to be tapped. my main questions are:

1. whats the best carb setup to convert to, and is it expensive.

2. what kind of power gains can be expected, and how badly will mpg suffer.

 

i've got enough power with my se to get in trouble, everything is stock except for cone filter, RB test pipe... and gutted interior. most people. think it sounds awesome, kind of like an old v8, the car sometimes idles weird but i actually like it like that!

so dude if your efi system is fine i don't think you should spend the money to go carb... sure you can get better gas milage, maybe better power. but it just wont adjust things automatically.

i don't know about georgia, but in california if you change to carb you will not pass smog. you can upgrade to efi but not downgrade to carb. if that matters to you then don't do it.

 

Why don't you put an S4 or S5 intake, which has a bigger TB, and go with a stand alone ECU? The only thing negative about the SE FI system is that the TB could be larger. Other than that, the FI was way ahead of its time. Personally, I would not give up FI to go carb unless the FI failed or was just a crappy system.

Mike

 

so could we put an s4 tb on an se?

 

S4 intake onto S3 threads.
https://www.rx7club.com/1st-gen-archive-71/got-se-you-gotta-do-mod-169237/
https://www.rx7club.com/1st-gen-archive-71/intake-s4-manafold-swap-complete-750214/

I've just finished installing an SE engine with stock LIM, RB UIM and RB Dellorto carb in my 76 Cosmo. I didn't go with FI for obvious reasons. Not going to say which is carb is best. It depends on what you use the car for. I've had the Dellorto on a 4-port 13B in the car for several years. Here in Southern Florida it's is fine for daily driving. It has great high rpm power and I've never needed to hook up the choke. Colder weather has a significant effect on warm up and driveability. When they sold it years ago, Racing Beat quoted 177hp with this intake, header, pre-silencer and Rb muffler. I think more than 1/2 of that is the free flowing exhaust.

http://www.gruntled.com/Dellorto/Page1.JPG
http://www.gruntled.com/Dellorto/Page2.JPG
http://www.gruntled.com/Dellorto/Page3.JPG

If you haven't yet, spend your money on exhaust or, if you don't have $1000 laying around, swap to an S4 intake. 17 MPG on the big street port 4-port 13B, headers, single presilencer and primaflow I have been running.

I know. I'll get a 4 port built and put the right engine back in, but I had this nice 6-port just waiting. Don't flame me Trochoid and Jeff20B

 

What would I flame you for? You answered the op's question and provided links, some of which I'd never seen before and learned a bit from reading them. In stock form, the 6-port engines are a decent all around engine. I have a spare S4 engine that may end up in the REPU in a pinch if I can't afford to build the one I want to for it. And it would be converted to a carb. My dislike for them comes when one trys to port them. They just don't have the same power gains that one can get with a 13B 4-port.

 

Well I can chime in on this one I have both. For autocross I run an 83 gsl with an 85 6port. I run a 48 dellorto on a racing beat upper. The reason for the carb was obvious but the Street Prepared legal motor puts down 150 at the wheels. We could make a little more top end power with a little more carb, but we would lose some mid range drivability very important for autocross.

That being said for a street car I would certainly stay with the FI, better all weather manners and smog legal. Have not dyno'd the 85 SE yet, but by the butt dyno I would guess there is not much difference in power

 

I put an S5 throttle body and intake manifold on my SE and I like it.

 

most mods you had to do to make it fit? i want to make sure of everything b4 i do it

 

wow, thanks for the responses guys. I was only going off of what i have been told about the gsl-se fuel injection system, which was obviously wrong, because until now i was leaning to converting to dual carbs.

im very interested in this s4 intake swap now. i will be installing a racing beat header and mid-pipe to accompany my power pulse catback soon, and that would be a good time to go ahead and throw on some intake parts. any suggestions on where i might purchase an s4 intake to do the swap? also, is there anything else i should look to pickup in the process. only other thing i could think of was oil injectors since the writeup states that the s3 injectors wont clear the s4 intake, however, im already premixing as i have yet to get my factory OMP to work, so i will probably remove it and install a blockoff plate.

 

Just do the s4 throttle body swap, the s3 intake is pretty good already and you'll preserve the factory look. Also, I did both the cone filter adapter and a drop in k&n panel filter. No real difference, and the drop in filter preserves the factory cai (as long at the intake tube only goes half way in front of the rad) and again you preserve the factory appearance. Pull the intake, clean it up, get the injectors cleaned professionally, install pineapple inserts, s4 throttlebody and panel filter. Finish the exhaust and you're set. Been around the block, had my SE for years now. I currently run a streetported 4 port with a camden. If I could go back (wayyyy back) and start over, I would do a s5 n/a streetported swap with renesis rotors, s5 vdi intake, light flywheel, standalone, s4 transmission and 4.44 gears. This would be a combination for great daily driving, good power, decent economy and tremendous reliability and relatively simple.

 

the s4 tb fits on the s3 intake?

 

not sure, only read about it but never done it.

 

how do you like the camden. the thought of ordering one when my taxes come back has been dancing in the back of my head for a couple weeks now, but my concerns are reliability and whether the power gained is worth the money invested. the reason i say this is I know that i can fabricate a junkyard turbo setup for less than what the camden costs, and even better, i have a brand new holset turbo sitting in a box in the basement. the only reason i thought about the camden is because a roots style blower = instant power on demand, no lag, and blowers tend to be less troublesome than turbos on daily driver applications.

 

i really like the camden, but it isn't as powerful as turbo. i think it makes an fc as fast as an rx8...

 

correct me if im wrong, but isnt an fc significantly heavier than an fb? also, i wouldnt expect it to put out as much as a turbo, but the instant power and reliability seem like it would be a fair trade off for a daily driver. i would HOPE that with the camden, a relatively stock 13b with exhaust and CAI would be over 200 hp at the wheels. I may get flamed for saying this, but ive never really considered the rx8 to be fast. based on the hp and weight, it seems to me that a 1st gen with 160rwhp should be able to keep up with it, if not outrun it in the quarter mile. I guess what im getting at is that for what it costs for an rx8 it hardly seems that you get your money's worth, and a mild rx7 should give it a run for its money for much less invested.

once again, i am by no means an expert on these cars, so feel free to correct me if im wrong here.

 

i was just going by the intro video found on the camden website, they raced an rx8 vs an fc

 

I would leave the FI...I think that is what makes the SE the SE...but thats me...

 

i honestly dont have anything against the fuel injection (other than the fact that i cant get the damn thing to idle cold), i just want somore power out of it and i wasnt sure what the best route would be to achieve that. as of right now i think im gonna swap on an s4 intake and rb header and see how she drives. i already have the header, but if anybody knows where there is an s4 intake for relatively cheap, let me know. it would be shipped to zip code 30188.

 

180 rwhp is realistic with the camden, max achieved has been 210. I like it for the torque, driveability and reliability, however a turbo can achieve much much more.

 

well of course, but like you said, my draw to the camden is the reliability. another plus is the fact that with a blower like that you have instant power.

 

true http://media.putfile.com/BRIDGPORTED-13B-COMPILATION

 

Mine will get some spray this spring

 

worth a look http://media.putfile.com/5th-Gears-N...Wizards-of-NOS