RX-7 Chris

iTrader: (19)

I have an '83 GSL w/ a large streetport 12A. I'm running a RB streetport holley setup and a single out RB header w/ 2.5" and 2 magnaflows. I have an electric fan setup. Stock ignition w/ MSD blaster II coils. No emisions, no A/C, K/N filter. RP oil in trans and rear, RB lightweight flywheel and Centerforce stage II clutch(have RB S/S to put in). I know I have more but I can't think of what else would make a difference in WHP. If you want to see my build, click in my sig.

My car makes 141 WHP @ 7K and 110 WLB @ 6100 on a mustang dyno. I want to hit my 150 WHP mark. What can I do you make this? I not going to make any changes to the internals because the motor is fairlly new. I'm keeping everything else I've done like the RB holley setup and exhaust.

I know I can gain some with ignition but not sure if that will get me 9 whp. I plan to go with a summit box and running a direct fire on leading. I will also be going with the Richard Sohn Metering Pump Adapter setup.

I'm also running stock '83 oil cooler setup but I will be changing to an FC cooler.

So what do you all think?

t_g_farrell

iTrader: (1)

Maybe go to a large weber downdraft carb and change out the header/exhaust for even better flowing components.

RX-7 Chris

iTrader: (19)

I'm really not wanting to change out those things. This car is a DD which is why I went with the Holley over a large weber downdraft. and my exhause is brand new and cost me over $500.

I'm hopping to squeeze a few whp out of the ignition and maybe a few if I go with synthetic oil but I can't think of what will give me any more. I also want this to be reliable whp.

PercentSevenC

So you want more power but you don't want to change anything? Ignition will get you a couple of HP tops and that's about all you can do for that setup. Maybe you can experiment with some sort of cold air intake?

RX-7 Chris

iTrader: (19)

I don't want to change the motor, intake, and exhaust. They are all new. I'm looking for 9whp in anything else I may not have thought of. I know this will be real hard.

4portgsl

For a bolt on way to get a considerable amount more horsepower, drop a camden supercharger on there. camdensuperchargers.com I'm curious, how do you like your RB holley? I want to put one on the 4 port 13b im putting together.

RX-7 Chris

iTrader: (19)

I like the RB holley a lot. Putting it on a dyno and tuning the car right made all the difference.

4portgsl

Great, that makes me feel better. I just looked at your cardomain page in your sig. You might be able to pick up a high end pony or two with a RB dual sheave alternator pulley. It slows down the alternator a little and runs two belts over the water pump which keeps it from slipping. You could also run the RB main pulley as long as you don't drive in traffic or have a large stereo cause it slows down the water pump and the alternator a good bit. That might give you a couple horses.

PercentSevenC

How much timing advance are you running?

Super82

iTrader: (1)

On a street port you should be going past 7000, I think. I've always heard streetports, depending on the ports, make their best power in the 7500ish range. Kind of a catch 22 though because thats where supposedly the stock apex seals start chattering.

Your horsepower seems quite low, honestly. You should be getting alot more power for a streetport. Off topic but does a weber net more power than a holley? Because those guys with webers can get around 200hp, I'd imagine as long as the holley can keep up with the fuel and air demands (which they can) then you should be able to as well.

4portgsl

You have to remember, his hp numbers are at the rear wheels. You lose a good chunk of power through the drivetrain. He is probably making 160 to 170 at the flywheel.

81gsl12a

iTrader: (1)

put nitrous on it ... im sure you will say no so lets lets change some other thing

here is where you may find your 9hp

header wrap and heat shield EVERYTHING
get header wrap and wrap the headers and the exhaust. i like to wrap my headers twice and exhaust once. heat shield the header then heat shield the intake manifold.
Summit has some lines that are fire proof and also heat shields. use them on the fuel lines. Run it anywhere there is heat close to the fuel lines under the car and all the lines under the hood.

change out your filter set up get a blow thru hat 70 buck on ebay and run a cold air set up to it. the cooler the air you get in the more power you make.. so run it b4 the rad. heat shield it also. get a k&n cone filter for it.

dont cheap out on the summit box get MSD Diggy 6 box and good wires. Ford motor sport wires are as good or better then MSD wires and much cheaper. SS blaster coils

play with fuel psi on the dyno. try going up 1 psi at a time. if it goes down in hp keep moving it up, it may end up coming up with more hp after the drop. everything you change will need a new tune.. timing is the same way move a lil at a time

also change your oil b4 the dyno run so its clean and fresh

also this is going to sound odd but only run 87 octane fuel

when its all said and done you should end up makeing that extra 9HP. At a price that you pockets may or may not be happy with.

I recommend Nitrous its cheap and fun it will make way more then 9hp

cheers PaTricK

lx_machado

iTrader: (13)

141 WHP seems low for a streetport to me. i made 120whp on my stock port 12a with the same mods you have.

im looking in to nitrous and you should too

bad 83

iTrader: (3)

Alot of BS on these HP numbers. Getting past 140 rwhp on a streetport is pretty dang good. If your wanting to keep the car as a daily, and you do not want to change anything internally, then you need to play with your timing, ignition, spark plugs, and carb jetting. This means ponying up for a wideband to tune with. Pushing 150 rwhp might just be possible. Or like Patrick suggested, a wet shot would put you well over that. Another option is of course going blowthrough. My last 12A turbo blowthrough was creeping up towards the 250 rwhp mark. Just my 2 cents

BeenJaminJames

Hmmm, those numbers seem kinda small to me for the mods you listed, I'm running a streetport 12A, similar setup, and I'm getting 163 to the wheels on the dyno last month. Like Super82 said, you should be shifting around 8,000 with a large sp, I suggest rebuilding and running racingbeat 3mm apex seals. They have always worked out for me, also go with an underdrive pulley and low octane gas. Remove your OMP, slap a blockoff plate on there, and run synthetic oil in your motor, and premix your gas with marvel mystery oil. That should get you pretty good numbers, else you carb/ignition is mistuned or you have a really goofy problem somewhere. Perhaps it is your exhaust, I'm running 3" with a single magnaflow. Well that's all I can think of this late in the day, it's 1am here in alabamer, and time for me to hit the sack, good luck!

bad 83

iTrader: (3)

No offence to anyone here, but if you don't have a dyno sheet proving your hp numbers, just don't spout off numbers. I've been doing this too long to listen to the BS.

Rotospeed

iTrader: (8)

get some 4.44 gears and put a lill more of your power to the down

Methanol+Boost

You guys talking flywheel Hp or Net? I think if you want the power for DD and have a holley manifold, go TBI like i did when i was fed up with carbs....and i had a stockport 12a with tandom 6als (each pickup not direct fire), blaster coils, b7es (1111) NGK's, moroso wires, Holley commander 950 ECU and 600 CFM TB, a road race header and royal purple.....147hp. TurboJet numbers, off the fly.

Methanol+Boost

Your absolutely right, but more importanty, if you recall how it was dynoed, add that too; like 4 portGSL.


Quote from local guy "Its got around 340 Hp, My G-TECH said so."

RX-7 Chris

iTrader: (19)

Here is my dyno sheet for anyone who hasn't looked at my cardomain site. One of the things I will say is that I put my car on a Mustang Dyno which is one of the most accurate and Conservative dynos out there. I could put my car on a different dyno and make 20 more hp but then I would be lieing to myself.

Also I do have upgraded seals but my power drops above 7k as you can see on my dyno sheet so there is no reason for me to shift higher.

Possible things to work on:

- Ignition - MSD 6 box (I'm running MSD blaster coils and Magnacor 8.5mm wires already)
- RB dual sheave alternator pulley
- header wrap (I do already have the heat shield for the intake)
- possible loss of power in rear (through PM) I have an '85 GSL rear I will be rebuilding and swapping with my '83 GSL rear.

Thanks for all the ideas.

RX-7 Chris

iTrader: (19)

I agree with you completely. 140 whp is great that is close to double what a stock car is making. A friend of mine is making about 155 whp with a similar porting but on a 13B 4 port and he is running duel downdraft webers with no chokes. He is also running an MSD box. His numbers are on the same dyno. So I guess I'm doing real good compared to him.

Whenever I go on the dyno I replace the spark plugs (always NGK) and change the oil.
I'm running the timing that RB recommended for the holley setup.

blackdeath647

iTrader: (2)

upgrade that ignition, make sure you get a better burn up there that should unlock quite a few ponies. i didn't see any ignition mods, you said you were working on it, better cables, spark plugs i believe that's where most of that needed hp will come from. or strip some of the interior off the car, it won't make more HP but it will make it faster lol

definitely add them heat shields and as already suggested, try to move the air pick up to outside the car, colder denser air will get you more HP, that's about the only things you can do w/out modifying your set up that much.

RX-7 Chris

iTrader: (19)

One thing I forgot to say is if you look at the A/F on the dyno sheet you can see that it spikes to 15.4 at about 3250 rpm. This is because I need to go to a larger AP jet.

Kentetsu

If your power is falling off at 7k with a street port, then I would suggest finding out why rather than adding new parts. I would guess that you either have a timing issue (lack of advance) or you need to re-tune your carb. I'm not familiar with Holleys, so I don't know how tuneable they are in reality. Ever consider a Sterling carb (highly tuneable)?

Other than that, try dumping a can of Seafoam in the tank before your runs. My car always runs strongest right after I treat it....

Also, there is all kinds of power hidden in the ignition systems of these cars. I had great success with the Transistor Trick ignition, but that's not exactly available right now unless you build it yourself (instruction on this forum). But its a great ignition system for under a hundred bucks easy.

Good luck man.


.

RX-7 Chris

iTrader: (19)

When I did the timing I set it to the RB recomendation of L 8 BTC, T 12 ATC. http://racingbeat.com/PDF/timingchart.pdf I will check and see it my car is really setup right because it has been a while since I double checked it.

The holley is very tunable so I should be able to get that figured out if that is the problem.