Rxmfn7

iTrader: (4)

Well Im selling my N/A FC(see sig) , just because its not fast enough. I will have close to $6k to spend on a car after I sell my FC. Originally I was looking for a turbo2 to buy, but was thinking of maybe getting a FB to build up instead. Ive driven a mildly modded '85 GS before, and truthfully my FC would've destroyed it. I was thinking of a 84-85 GSL, with a big-*** carb, header, fuel, etc... How much power can one make with these mods? Id like to hit 13s in the 1/4. Sorry if I sound stupid, but I dont know too much about FBs, but have heard that they can make decent power , just wondering what Id be looking at for my budget? Thanks

diabolical1

iTrader: (3)

well ... i'm not being a smart-*** here, but are you conflicting your thread title? when you said "built 12A"?

the simple answer is: roughly 150 HP with the stock ports.

the less-than-simple answer is: if you're going to build a 12A for the street, and you want to run 13's ... then you will need some more help besides the "big-*** carb, header, fuel, etc ..." you'll have to work on the "etc." part a bit more. start with a good streetport and try to lighten the car while you're tuning it. i don't know if that will get you clearly into 13's, but it will be a mighty fine start. (i personally doubt it, but then again i'm not really big on 1/4 mile times ... so someone else will have to help you on that goal) with a properly sized and tuned streetport, theoretically, you should be looking at 170-190+ HP, but you're probably safer betting on 175+, especially with the carbie.

other options: start with an SE (13B, FI, more torque, and rear is geared for torque) or else an S or GS without the sunroof (less weight to start with) ... you'd just need to swap in the GSL rear.

hope this helps a bit ...

Keaponlaffen

I think he means "built" as in "all the possible HP squeezed out... every last drop of it...

Jeff

Rxmfn7

iTrader: (4)

Yep, thats what I meant. Id like a GSL for the rear disks and such, and was thinking that a 12A would be better than the 13B in the GSL-SE from a performance standpoint because of the carb vs the FI. Yes I know stock for stock the SE will be faster, but it is much easier to throw on a 550 carb than it is to mess with the FI. I was thinking large streetport, 550 carb, header, exhaust, flywheel, clutch, fuel, lighten car, ......stuff like that. Could I hit my 13second goal with these mods?

diabolical1

iTrader: (3)

true indeed, but you could always throw that 550 (Holley-man, eh? ) on the 13B just as well ... the FI system, though it may be good for driving, and even can be tweaked a bit for performance, it is still quite archaic (in my opinion)

the 12A route, i'm still unsure if you'd be running consistent 13's,
the 13B route, i read about a few cars that run consistent mid-to-high 13's - but like i said, i only "read" about them ... never saw it with my own eyes.

Directfreak

iTrader: (2)

I ran Mid 14's in my Streetported SE with the FI. With a nice Carb, I probably would've hit low 14's.

tTo run 13's, you need a bridgeport. Or a Street port with some nitrous. a 13B would be a much better choice, as it will get you the power levels you want, easier.

I am not even going into Boosted applications.

I don't think

Rxmfn7

iTrader: (4)

OK, thanks all

WackyRotary

IF you want a quarter mile Rx-7 powered by a 12a, you will need lots of horsepower with low car weight. If you want relatively cheap hp, you can go with Wet Nos always. Or a blow-through turbo. And if you can handle opening the engine, porting is a critical base to start from since completely stock 12a blocks are not the best starting point in my opinion.

But take it from a daily driver of a 12a modd'd into a bridgeport, they are fun and zippy. But don't make any lowend power and is either full throttle or idle, not much in between power with a weber at least. Also pretty worthless MPG any way you drive it, so might as well drive it hard. But it isn't that expensive to build if you know how to port yourself for fun highend power from a normally asperated engine.

WackyRotary

Oh forgot to mention, my bridgeport 12a isn't a 13 second car. Probably mid 14's easy though. If I removed all excess weight, I see no problem to reach into high 13's. Also, you CAN'T drive around with no muffling with bridgeport, its WAY WAY too loud, but it does make about 10% more power when I drove it with no muffler but too loud for any country road(as its audible from 2miles away easy at full throttle) let alone in a big city.

Logo

Wacky, what does your exhaust setup look like?

Rxmfn7, hitman is making 178rwhp with a mild streetport and efi on an aftermarket injected 12a. I would think that a similiar setup with a bit more port timing, better gearing, and a lightened load "might" be capable of high 13's.

WackyRotary

I wasn't rich enough to afford EFI otherwise I would of simply went TII halteched at the time instead of the 12a bridgeport project which I had plenty of parts for.

Anyways, like you hinted, everything needs to be optimized to achieve 13's with low hp. This bridgeport I have is probably not putting out as much hp as it should due to proper jets and proper exhaust, but is not too far off as it was. The replacement muffler does hold it back considerably, for full sprints up to 8500rpm. I have custom equal length long tubes that collect near the rear axle, but don't have any good pics scanned. going from streetport headers to this was the BIGGEST power gain ever(6000rpm-8???rpm), but also hurt power under 4000rpm afterwards. I get better mpg if I keep it above 4000rpm strangely at crusing speeds.

The biggest problem with a bridgeport's powerband is probably gearing, which is completely stock on mine and old cooper cobra's which spin a bit before catching(biggest problem with bridgeports is the peaky hp). Dump the clutch SLIGHTLY too low, it bogs badly momentarily, SLIGHTLY too high and it spins like mad and worse with the wrong tires, there is NO in-between which is the tricky part. I am sure a 4.44 would be a far better choice since it would get it into powerband quicker. And removal of dead weight(most of the interior, I need it for now though). But not so good for simply a quarter mile run which isn't my main goal.

XLR8

iTrader: (52)

With 6k for a 1st gen. I would look for a GSL-SE with good body, little to no rust, possibly blown and do a TII swap with a J-spec, or custom setup controled by a haltech. MOP

Good luck.

Fennix_sr

im going to be having my 12a street ported... and getting RB header PS and a SS muffler, just curious what kina Horsepower im gonna get outa it, i heard a stock 12a with a 4barrel carb gets roughly 100hp or a little over that . also adding a cold air intake and new air filter prety quick.

diabolical1

iTrader: (3)

wackyrotary, i'm honestly not pointing fingers ... but having a bridgeport person say this, i just had use the quote to illustrate what i keep telling people that want to run bridges on the street as their daily driver. this is exactly why it won't work ... at least, not as well as a streetport. the low RPM port velocity and overall efficiency is not worth it in my book, and i think i have a pretty high tolerance for things that others may find annoying.

WackyRotary

I understand why some people don't like bridgeports for the streets and I don't make decisions for anyone but me ofcourse.

I used to think it would be bad to keep it above 4000rpm or near there(3500-4500rpm) crusing, but I don't see what it hurts? If you drive it hard you get 14mpg, if you drive it really light you get 14.5mpg, so drive it hard all the time!! LOL

I run premix ofcourse and carbon seals. Also, if you drive like grandma sustained(below 3000rpm), this engine is NOT ... NOT... NOT for you. Carbon seals don't like low rpm for long duration I believe since they blowby more and carbon builds up near the tips then(not from the seals, from the combustion silly)..not a problem when its driven hard consistently . The biggest complain of mine is the work to pre-mix at every fill-up. Otherwise I'd take a bridgeported engine over a mildport 12a anyday for the extra acceration. But this is just my opinion ONLY.

HOWEVER, if I lived in a big metropolitian area, I would NOT recommend a bridgeport in traffic conditions.

REVHED

With the way I drive my extend port, a bridgey is just the natural progression.

rotary emotions

The way I drive my 12A, 13B Peripheral Port is the natural progression
that's the fun part of being close to Germany, where you are allowed to go as-fast-as-you-can on the highways... (never got over the 215km/h with my FB and 240km/h with the FD, though... That's the not-so-fun part of taken your wife with you when you drive in Germany )

12aPwr

hey why hasnt anyone mentioned a 13b 4port? how much power would that accomplsh with the right bolt ons? and of course lightened car

BadAssRX-7

atkins is showing 250(i think) on a ported 12psi 7" super charged 12a... look on ther page they got some dyno #'s posted