fastrotaries

I'm curious to know what the fastest time that anybody knows of, for a 12a is? I don't want to know about blow through turbo's or superchargers. If someone used good ol' N2O then that 's cool too. Please include all the mods needed to run that time. Gears, flywheel, carb, exhaust and tires. My friend has several 1 st gens and i'm seeking to make one go fast. A N/A V-tec killer if you will.

peejay

Stock '79s generally ran 17 flat. FBs were generally 1/2 second slower because of the added weight.

RotorMotorDriver

iTrader: (1)

My bone stock 85 GSL w/12A does 0-60 in ~9 sec. I dunno if thats good or bad, but thats what it runs. As far as 1/4 mile, i have no idea...4 days maybe ...lol j/k

~T.J.

fastrotaries

Ok that's good how about people with mods out there. Who haven't ported their motors.

RXcetera

A maxed out stockport 12A will do low 15's as ~150hp is all you'll be able to produce regardless of mods. A gutted out 1st gen with minimal interior and various light weight mods could possibly do high 14's. The general rule though is that most modified 12A stockports tend to hover around the low 15's.

fastrotaries

So if i had a quality carburator, exhaust, flywheel and the rest of the bolt-ons, my time would be in the low 15's. given that traction is good. having said that would a 50 shot (75 for you crazy fools out there) of N2O bring the car, to the 14 sec range.

peejay

I've seen someone running mid 15's with a RB exhaust and a rejetted carb, still stock everything else.

You could hit the 14's with nitrous and a little lightening, stock everything else. I wouldn't recommend it though, 'cos nitrous is the path to the Dark Side of the Force.

moremazda

iTrader: (4)

I'am @15.7 w/ a full racing beat short primary exhaust, underdrive pullys, and a bone stock carb with a hacked air cleaner housing.

But, yes, you have the right idea. Setting up nitrous is just like setting up a turbo if you do it half-assed you will end-up with with a half-assed paper weight. I've seen a stock 12a in the low 12's with severe traction withdrawls, with a propperly set up 150hp shot.

Ryan

piston pounder

My fastest time my first time at the strip was 15.4, Thats with the weber carb and mindtrain exhaust. Not to mention the completely gutted interior. I could possibly go a flat 15.0 with more practice launching. Hopefully alot faster with the half bridge im building!.

fastrotaries

'cos nitrous is the path to the Dark Side of the Force.

No Peejay......."fear leads to anger, anger leads to hate, hate leads to suffering." Master Yoda.......Nitrous just leads to happy-times

RXcetera

My '83 GS w/stockport 12A runs low 15's with RB streetport exhaust, Dellorto 48 DHLA carb, stock ignition, stock timing, stock new clutch and leather interior. It's all in the fine tuning .

fastrotaries

Does that include a lightweight flywheel? My friend got one on his 88 SE and it made such a huge diference. Plus the stock ones are sooo heavy. You could also try gears if you could get your hands on a good used set. How hard is that carb to tune on the street? And they are rare to come by....right? I'm sorry for sounding ignorant, i own a TII

V8kilr

im hitting low 14's with these mods
dual msd 6a
jacobs wires
always new ngk plugs
K&N air filter
functional hood scoop with modified air box "this helped out 3rd ALOT"
Full exhaust "Custom"
Street strip clutch
no a/c or a/c core
no air pump
some weight reduction in interior
sumitomo tires
tighter springs
welded diff
carb slightly modded
shotend shifter

everything else is bone stock "as far as peformance"

thining of getting that 7" camden supercharger with next years tax return
hopeing to hit low 13's
can we say corvette killer

V8kilr

oh by the way because of the gearing on these cars their not that great in the 1/4 but do wonders in the 1/8 also awsome 0-45 for whatever thats worth
@ 45 its time for me to shift into 3rd

peejay

Yeah I was going over the videos I made in November, and I realized just how skewed my times have been.

I mean, 1st gear was over with before the 330'. 2nd gear was over WELL before the 1/8th. But I'd never get out of 3rd.

Looking at the times, my best 1/8th was 9.694 at 72.37, and they were normally in the 9.7-9.9 range at around 71mph. (Hey sometimes you click off that PERFECT run ) http://www.mustangworks.com/analyzer.html has a 1/8th mile to 1/4mi converter.

Hmm that calculates to 15.12 at 91.19. Pretty good, that run was 15.114 at 90.49. But considering that there was no shift in the second 18th mile I should have been quicker, and nearly 3/4mph is nothing to sneeze at either! MPH is a clear indicator of power put down, while ET is more about driving ability.

So my car was most likely fuel starving a little in the second half of the runs! I could squeeze out a few hundred more RPM before having to shift again (only turning ~7700 through the traps) so i could easily get up another MPH or so before having to shift. Heck, before I swapped fuel pumps I was running 15.7's at 89, so the pump seemed to have helped times more than MPH. But obviously I do need MORE pump.

I keep forgetting that that particular combination will never run again What am I saying, I need more pump... the car needs a lot more than a mere larger fuel pump. I'll just have to file this away in the ol' noggin - Purolator pumps are only good to about 130hp, after that just spend the money and get a Holley.

Heck at only 130hp I didn't really need to have a ported engine. HMM. (Naw, the '85 is too nice to strip out to turn into a drag racer, and WOULD need a ported engine to make enough power to haul itself as fast as WT was... looks like my drag racin's on hold one way or another!)

pjr

iTrader: (8)

OK V8Kilr, a little help please from the East Side to the West Side please! What's a "dual msd 6a?" Also, is that with a 1st Gen or 2nd gen RX-7?

RXcetera

Lol, I would kill to see a 2nd gen NA stockport run in the 14's. That kind of thing doesnt happen. When a NA 2nd gen breaks into the 15's its a cause for great celebration.

V8kilr, pardon me for being skeptical, but those times are virtualy impossible to acheive with a stockport 12A with the minimal mods you stated. Please tell me your engine is ported and you arent just BSing some made up times . The only stockport 12A RX-7 I've ever seen in the mid 14's was a stripped out (no interior) early 1st gen with an open header, big Holley, drag tires and countless other mods.

Fastrotaries, I have the stock '85 flywheel (my engine is an '85).

peejay

Figuring that 150hp is as much as you're really going to get from a stock port 12A, the car with driver would have to weigh in the 2150-2200lb range. My '80 weighed 2210 without driver, but then again it still had stuff like carpeting and A/C (but no spare tire or rear sound-deadener or jack or fuel in the tank...) Even assuming a 150lb driver that's 200lb you'd have to strip out... where from? A/C is only going to take out 30 pounds max.

RXcetera

Even then, I figure a 150hp, 2150 pound RX-7 (including driver) would run in the HIGH 14's. The guy I saw running in the 14's had NO interior (no passenger seat, no dash, no carpet etc etc... I dont even think he had side windows in that thing anymore lol).

PaulFitzwarryne

Out of interest I sat down one night and designed the best stock ported NA 12a that money could buy. There were three restrictions, stock internals with no fancy rotors, legal noise/emision and stock interior.

After much brainstorming and a heafty international phone bill the highest that came up was 162 hp at the fly wheel, with a 1/4 time of 14.7 seconds. We could marginally improve on that with a stock UK specifcation motor and numerous exotic metal parts but ruled that out.

14.7 appeared the utimate target to achieve if you wanted to actually build the fastest. But as Peejay said a RX-7 is too nice to turn into a drag racer. I have a stock R34, loaded with the family and their luggage
which is seconds quicker than any modified stockported 12a.

However, I much rather enjoy driving my 1984 RX7, its detuned by being a convertible, with a/c, cruise control, and a great stereo system. Added weight includes a strut tower bar and bigger suspension items. But it cruises at the legal limit in style for hours. There are a few minor power improvements put on to keep my tune shop financially solvent. Its best 1/4 has been 15.3 seconds down hill and wind assisted. On the track it achieved 15.6 seconds with a full load of 50 CDs, a medical kit, and a collection of road maps. For the record the temperature was 36 C degrees.

peejay

No I said MY RX-7 is too nice to turn into a drag racer. Big difference. I had no problems with turning my '80 into a budget drag racer. For one thing the '80 didn't come with power everything, and the interior was all dried out and shunk and cracking, and the body was starting to crumble, so I figured the car wasn't going to be around long so I'd better start modifying it before it got too late.

fastrotaries

Right on PJ

V8kilr

its on an 84 gs
im running dual msd 6a's
that means there are two msd 6a's under my hood
1 for primary
2 for secondary

V8kilr

im 5'11 and weigh 130 lbs
my car has no interior in the back
no carpeting at all
no door panels
no radio or speakers
no passenger seat during runs
anything under hood that was not needed was removed
i have header dump for drag racing

the clutch pressure plate,welded diff,tight springs and shocks made a hell of a difference

also i welded in custom wheel wells for strength

like ive said a million times my suspension is stiff if i run over an ant it will knock you outta your seat.

oh yea my engine only has around 40,000 on a custom rebuild,but no porting,in case i did not mention that already

V8kilr

in my car to hit low 14's you would need an estimate of 130-135hp,car comes stock with 105 if im correct.that leaves 25-30 hp to be gained,plus with a better clutch and welded diff i put more of my hp to the ground over a stock rx7.maybe none of you here have ever purchased or modded these items,the diference is a diference you can feel.

after i put the performance clutch in i had a much harder time trying to keep my rear tires from spinning then with the old clutch,the old clutch was only 2 months old with very little abuse,sold it on ebay and the guy was very happy with my old clutch,that just shows that more hp and torque were carried to the rear end from the tranny.
thats why i bough the new tires that i have now.