prefix

Hey everyone I was wondering if anyone had any ideas on this. I have a fb with a 4 port 13b swap(out of an rx-5), that has a header, 2.5" exhaust, racing beat intake and weber dcoe carb. I went to the track and ran 16.6. That just seems slow to me for all the upgrades that I have. Does anyone have any idea why it would be this slow?

85rotarypower

Mabey the carb is way out of tune. With that setup, you should be making someware around 150-160 hp, which is good for low 15's.

FB II

get that carb TUNED!!!!!!

85rotarypower

So I was actually right???? I know jack **** about carbs too.

FB II

well, that's the first place i would look. GRANTED... everything else seems good. maybe check the ignition? fuel flow, how is your launch? shift points? car ever been on a dyno? oh, and maybe time for a compression check?

YapaKanichi

what would he be doing if he had a SP and an electric fan

red13brx7

better than a 16.6 I can tell you that.. more like a mid 14.

85rotarypower

If he streetported it, I would guess someware around 200 hp. So mid to low 14's would be reachable if you have very good launch and excellent shifting technique. In otherwords, lighning fast shifts. You would probably need a heavy duty clutch to keep it from sliping too much and give better launch and shifts.

prefix

Does anyone have any carb and timing tips perhaps to get the most power?

Directfreak

iTrader: (2)

Are you at any high elevation?

That does sound slow. The RX-5 13B had small tiny ports though..

Compression?

FB II

shm21284

150-160 HP should put you into the mid 15s, same as a 12A with RB intake, dellorto side draft, RB headers, straight exhaust. your car's as fast as a good running stock 12A rx7 with K&N air filter (my friend's ran that all the time)

prefix

Not at a high elevation, 2500 ft. I'll have to run a compression check

85rotarypower

Your compression would have to be pretty damn crappy to be running that slow. Your car would also run rough. Judging from what you have said, I think you should at least be running in the low 15's.

peejay

My mostly stock GSL runs 16.4 with more in it so there's something up.

What are your trap speeds? Trap speed is an indication of how much power you're making, ET is an indication of how good of a launch you have and how well you drive it.

prefix

Trap speed is 81. I'll need to get an MSD, judging by how nasty the plugs look.

K-Tune

iTrader: (26)

my car ran a 15.29 on the stock carb (and shotty tires)

mwatson184

If by nasty you mean black, then you are running too rich.

prefix

Yea, I think that's one of the problems. The other today is that I realized I was mixing in too much oil in the gas. My friend who I bought the car from said that you should mix in about 40ccs per gallon, when in reality it should be more around 25 :/ for a 150:1 mix. So we'll what happens when i get those two things fixed.

peejay

If your trap speed is 81 then you're probably driving it OK! I hate to say it's the car's fault since fixing the driver is free, but that's how it goes.

You didn't mention what fuel pump you have. Stock fuel pump is barely sufficient to make stock power.

prefix

I'm working on the fuel pump issue. A carter street/strip is in the works, I'm just too damn poor right now. You think that would make a big difference?

peejay

Huge.

prefix

Now which would be better, the carter pump that flows at 4-6psi or 6-8? They both put out about 70gph.

79+80+84_rx-7

either one, you will need a fuel pressure regulator to go with it, and a psi gauge for safe sakes....


Is it cutting out in the higher rpms?

prefix

I have a psi gauge. It's not cutting out at higher rpms, but the engine doesn't seem to get as much power at the higher rpms.