BlastinSideways12A

You can have all the mods you want but if you can't tune everything its gonna be slow and eat gas. When I bought my 85 GSL with full RB streetport exhaust, Weber DCOE 48 carb, and electric fan I was very disappointed with it. I only ran a 17.2 in the quarter (85 degree humid day @ 1100 feet) which is barely faster my stock 1982 got. The car was pig rich (10:1 at redline when I put the wideband in). I tuned the car a little better with the air bleeds that I had and installed DLIDFIS and the car was COMPLETELY different. It still was pig rich and could have made considerably more power if optimised. I do consider the header to be an extremely effective mod. I have since sold the carb to a friend and will be running a VERY mild port (just smoothened intake ports and slightly raised exhaust ports) and using EFI on it. Its gonna be a gas mileage project.

rotary emotions

My Mikuni setup with RB exhaust system (I'm now working on a TII swap) was very much quicker then a stock setup, but I have no idea how much hp it really did have. Claims were 150hp (flywheel) for such a setup, which seems rather acceptable since RB has this numbers on their site too.
Ported engines with Webers and full exhaust systems should be around 180hp or more.
As said before, of course any setup will only work properly if the tuning is right. But that goes for any setup, wether modded or stock.

aussiesmg

iTrader: (1)

A ported motor is not a guarantee of more power depends on how well it was done, how many miles its done, who built it, who tuned it, what ignition, is the carb jetted correctly and so on....

A good ported 12a engine should get up to 200 HP when well sorted.

Tanjo

I think the easiest and cheapest mod that was actually noticable was an E-fan. I pulled a fan off of a fiero for 10 bucks, and I actually felt a diffrence on the ol butt dyno. Then came a header/exhaust and carb. But, the first mod I would do on an FB, other than a GSL LSD swap, would be an Efan. If you dont belive me, spend the 10 bucks and 1 hour of time to put it on. Its amazing.

aussiesmg

iTrader: (1)

Try the ignition upgrades that the 2GCDFIS and offshoots give if you want value for HP.

RUBY7

I also think these figures are exagerated, before fuel injection my well sorted streetport with modded nikki, racing beat dual exhaust was putting out 130 rwhp. What sort of drive train loss are these figures based on? With these mods drive train loss would be no more than 10%. I cant really see any unported na 12A with 135rwhp

jays83gsl

Even so, I don't think I'm getting the power I should be. Not 200 FWHP. Maybe the carb was crap from the beginning? What sort of times should I have been running?

vxturboxv

iTrader: (2)

at 2450lbs (not sure exactly what U weigh) you should be running mid to low 14's with 200 FWHP. Assuming good traction etc...

jays83gsl

I'm assuming that I've shaved off about 200 pounds. I've removed ALL tar, all padding, storage bin, rear tires, everything unnecessary in the engine bay (including the ENTIRE A/C system), RB exhaust (I'm sure that alone took off almost fifty pounds!), passenger seat. . . basically this is a stipped down "race" car.
So, not knowing the exact weight I started at, I should be between 2150 and 2250.

I have some fat Goodyears in the back (on the stock 13's) and normal sized in the front. They don't offer the BEST traction, but they're fair.

I'm starting to think this carb was a bum deal.

aussiesmg

iTrader: (1)

These mods don't do anything to improve drivetrain loss, in fact with more power you're probably losing more through the clutch unless its upgraded also. drivetrain loss is the power it takes to turn the clutch, flywheel, driveshaft, differental, axles, wheels and tires.

You actual loss is more likely to be close to 15/20%

I know of many unported rebuilt 12a engine doing at least 135 RWHP, but we were talking flywheel HP for an original motor.

My friend Chuck's RX3 is doing about 200 RWHP with streetporting, if you dont believe me, come and try racing it.........

RUBY7

20% divetrain loss on an RX7 is absurd, Pure and simple. No one suggested the mods would lessen drive train loss. MY point is with 50,60,70% drivetrain loss these motors are capable of anything. Why not 300hp at the fly.

Without dyno sheets on these claims I will stand by what I have said. I too know plenty of 12A owners ported and not, blown and NA. I have witnessed many dyno runs . People should really talk about what their own car does and what they know is fact, not what their mate Chucks car does. Unlike most I do have sheets to prove it.

The thread starter here is asking what sort of power gains he should see out of some simple & modest mods. Not Injected, not Webbered or the like.

Be real folks.

Rotor13B

Next time read the WHOLE thread. The O.P. Clearly stated that you couldn't get a 150 fwhp out of a RB intake and RB full exhaust. Now seeing as how they're talking about an aftermarket intake, More than likely it's going to have either a sidedraft or a holley connected to it. The general consensus is the 12a in stock form with mods usually runs out of steam at about 150 fwhp. Thank you please drive through.

Kentetsu

Single best mod that gave me the highest returns in power and driveability was the Transistor Trick ignition. However, at that point I already had a complete exhaust so I'm not sure if you would get the same results with stock exhaust. Just a thought...

BlastinSideways12A

I also agree with the guy about the fan. Especially if your fan clutch is stuck.