Goal: 160-170whp. How does it look?
Thread Starter
'84 RX-7 GSL
Joined: Aug 2004
Posts: 266
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From: Tulsa, Oklahoma
Goal: 160-170whp. How does it look?
Copied from nopiston but I feel this site usually gives better advice... only posted there 'cause this site is blocked at work. 
Like the topic says I'm putting my goal at around 160-170whp for my n/a s4.
Mods done so far:
Racingbeat cat-back
Racingbeat header
Cold air intake (can't remember which one of the top of my head) (also unshielded at the moment)
HKS ignition
a/c and power steering removed
Koyorad radiator
Most emissions removed
All drivetrain should be good for the power already with the new clutch / flywheel and everything I've installed
Streetport (supposedly... I actually haven't driven the car yet.. just bought while I'm still in Iraq but I'll find out on the rebuild)
Plans to make the power:
Going to straight pipe the cats (yay no emissions!)
Holley intake / carb (with including mods i.e. fuel pump etc etc...)
If I decide to stay with 6 port... street port primary with a bridged auxilary and pineapple express sleeve inserts or whatever they're called.
Exhaust ports ported as well
If I go 4 port then half bridge
Make new cold air box for the carb'd unit
s6 rotors
Banzai-racing's rebuild kit with the s6 springs and whatnot
... not quite sure what else I'll need. Also would like to know if any 6 port guys have a similar setup and do your aux ports open? Or is there not enough back pressure and I'll have to do the electric modified ones? Also anything I should add for reliability?
I'm still pretty new to the FC thing... spent years researching FD but can't buy one yet...
Thanks in advance for helping me with my post deployment shopping list. :P
Like the topic says I'm putting my goal at around 160-170whp for my n/a s4.
Mods done so far:
Racingbeat cat-back
Racingbeat header
Cold air intake (can't remember which one of the top of my head) (also unshielded at the moment)
HKS ignition
a/c and power steering removed
Koyorad radiator
Most emissions removed
All drivetrain should be good for the power already with the new clutch / flywheel and everything I've installed
Streetport (supposedly... I actually haven't driven the car yet.. just bought while I'm still in Iraq but I'll find out on the rebuild)
Plans to make the power:
Going to straight pipe the cats (yay no emissions!)
Holley intake / carb (with including mods i.e. fuel pump etc etc...)
If I decide to stay with 6 port... street port primary with a bridged auxilary and pineapple express sleeve inserts or whatever they're called.
Exhaust ports ported as well
If I go 4 port then half bridge
Make new cold air box for the carb'd unit
s6 rotors
Banzai-racing's rebuild kit with the s6 springs and whatnot
... not quite sure what else I'll need. Also would like to know if any 6 port guys have a similar setup and do your aux ports open? Or is there not enough back pressure and I'll have to do the electric modified ones? Also anything I should add for reliability?
I'm still pretty new to the FC thing... spent years researching FD but can't buy one yet...
Thanks in advance for helping me with my post deployment shopping list. :P
First thing would be to get baseline numbers.
Before you can figure a path to 170hp, you need to know where you are now.
What kind of "power" are you after that will be more easily attained with a carb instead of the FI?
Before you can figure a path to 170hp, you need to know where you are now.
What kind of "power" are you after that will be more easily attained with a carb instead of the FI?
intake an open exhaust nets good numbers on a rotary, i would keep the FI tho, and get the aux port incerts from pineapple. and make sure the aux ports are working and move very freely, then you'll have to find a way to actiave, or just remove them intirely.
you lose bottom end, but you gain abit up top, i trapped 9.2 with a 2.1 60 foot in the 1/8 mile, which is similar to what a 180 hp stock turboII can do. infact i could only get a 9.4 when my turbo II was completely stock.
if your planning on rebuilding anyway go with 9.7 rotors, the cr helps a lil bit, but they are lighter and will peak in hp higher in revs.
you lose bottom end, but you gain abit up top, i trapped 9.2 with a 2.1 60 foot in the 1/8 mile, which is similar to what a 180 hp stock turboII can do. infact i could only get a 9.4 when my turbo II was completely stock.
if your planning on rebuilding anyway go with 9.7 rotors, the cr helps a lil bit, but they are lighter and will peak in hp higher in revs.
Thread Starter
'84 RX-7 GSL
Joined: Aug 2004
Posts: 266
Likes: 0
From: Tulsa, Oklahoma
EFI just seems like such a PITA....
I would LOVE to get baseline numbers... but currently in Iraq. This is more of a me figuring out what all I need to do when I get back so I can shop around for now. ^_^
Thread Starter
'84 RX-7 GSL
Joined: Aug 2004
Posts: 266
Likes: 0
From: Tulsa, Oklahoma
Well I think I was just sold on the EFI setup thanks to a post that Aaroncake made in another thread. ^_^
So any other suggestions for me? I'll edit my original post to reflect the EFI changes instead of carb.
Edit: Guess it's too late to edit the original.... so here it is
Instead of Carb it'll be...
RTEK 2.0 (just need to find someone to tune)
Port match UIM / LIM
TB mod (debatable... I hear good and bad things about this)
Shield the CAI I currently have with a "cold air box" and maybe heat tape around the pipe... might not be necessary for that though
Get the injectors cleaned and upgrade to t2 secondaries
Think that should be about it... I'm not THAT keen on EFI systems yet. Inexperienced. :P
If you want to downgrade to a carb, it is pretty easy.
Pick up an appropriate RB lower intake for the carb you wish to run. Mazdatrix as well as some of the other vendors sell them.
Either get a fuel pressure regulator designed to drop the pressure from the EFI pump, or get a fuel pump designed for a carburetor. You'll need to wire the pump to run continuously with the key on, so jump the ignition switch to the main fuel pump relay (unsafe). Put an inertia/flipover switch in series with that line to make it safe.
Get an electronic distributor from the 1st gen years 82-85. Remove the CAS and stock coils. Install dizzy and wires. Use two 1st gen coils or equivalent aftermarket. See the 1st gen FSM for how to wire it up.
And you're done. You have now downgraded your car and can enjoy poorer fuel economy and less power overall.
But wait, you're going turbo....So, you need to boost prep the carb. You'll also need more fuel pressure, so get the appropriate rising rate regulator.
You can't advance timing under boost, so you'll need to lock the dizzy at 15 degrees or so by removing the vacuum can, removing the flyweights and tack welding the plate. Note that you can't use a MSD retard box because the car has two ignition systems; leading and trailing. You'd need two of everything (big waste of money). Now you have a 15 degrees of timing at all load points, so enjoy the poor fuel economy, poor idle, glowing exhaust manifold and anemic performance in the midrange. But hell, it will be really fast at wide open throttle, and that's all that counts, right?
Meanwhile the guys that spend $1000 on an "expensive" and "complicated" standalone are making 500HP, getting 30 MPG on the highway and have a car that starts hot or cold...
Pick up an appropriate RB lower intake for the carb you wish to run. Mazdatrix as well as some of the other vendors sell them.
Either get a fuel pressure regulator designed to drop the pressure from the EFI pump, or get a fuel pump designed for a carburetor. You'll need to wire the pump to run continuously with the key on, so jump the ignition switch to the main fuel pump relay (unsafe). Put an inertia/flipover switch in series with that line to make it safe.
Get an electronic distributor from the 1st gen years 82-85. Remove the CAS and stock coils. Install dizzy and wires. Use two 1st gen coils or equivalent aftermarket. See the 1st gen FSM for how to wire it up.
And you're done. You have now downgraded your car and can enjoy poorer fuel economy and less power overall.
But wait, you're going turbo....So, you need to boost prep the carb. You'll also need more fuel pressure, so get the appropriate rising rate regulator.
You can't advance timing under boost, so you'll need to lock the dizzy at 15 degrees or so by removing the vacuum can, removing the flyweights and tack welding the plate. Note that you can't use a MSD retard box because the car has two ignition systems; leading and trailing. You'd need two of everything (big waste of money). Now you have a 15 degrees of timing at all load points, so enjoy the poor fuel economy, poor idle, glowing exhaust manifold and anemic performance in the midrange. But hell, it will be really fast at wide open throttle, and that's all that counts, right?
Meanwhile the guys that spend $1000 on an "expensive" and "complicated" standalone are making 500HP, getting 30 MPG on the highway and have a car that starts hot or cold...
So any other suggestions for me? I'll edit my original post to reflect the EFI changes instead of carb.
Edit: Guess it's too late to edit the original.... so here it is
Instead of Carb it'll be...
RTEK 2.0 (just need to find someone to tune)
Port match UIM / LIM
TB mod (debatable... I hear good and bad things about this)
Shield the CAI I currently have with a "cold air box" and maybe heat tape around the pipe... might not be necessary for that though
Get the injectors cleaned and upgrade to t2 secondaries
Think that should be about it... I'm not THAT keen on EFI systems yet. Inexperienced. :P
Thread Starter
'84 RX-7 GSL
Joined: Aug 2004
Posts: 266
Likes: 0
From: Tulsa, Oklahoma
intake an open exhaust nets good numbers on a rotary, i would keep the FI tho, and get the aux port incerts from pineapple. and make sure the aux ports are working and move very freely, then you'll have to find a way to actiave, or just remove them intirely.
you lose bottom end, but you gain abit up top, i trapped 9.2 with a 2.1 60 foot in the 1/8 mile, which is similar to what a 180 hp stock turboII can do. infact i could only get a 9.4 when my turbo II was completely stock.
if your planning on rebuilding anyway go with 9.7 rotors, the cr helps a lil bit, but they are lighter and will peak in hp higher in revs.
you lose bottom end, but you gain abit up top, i trapped 9.2 with a 2.1 60 foot in the 1/8 mile, which is similar to what a 180 hp stock turboII can do. infact i could only get a 9.4 when my turbo II was completely stock.
if your planning on rebuilding anyway go with 9.7 rotors, the cr helps a lil bit, but they are lighter and will peak in hp higher in revs.
So you think I'll lose the aux port activation from installing the straight pipe in replacement of the cats then?
Don't get S6 rotors, S4 N/A have 9.4, S5 t2 and S6 have 9.0. If you want to upgrade your rotors get the S5 N/A's they're 9.7:1 but they're sometimes hard to come by. You'll be losing power if you went to the S6's, but they are lighter than S4's I'm pretty sure.
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Thread Starter
'84 RX-7 GSL
Joined: Aug 2004
Posts: 266
Likes: 0
From: Tulsa, Oklahoma
Right! I've already mentioned that typo I had. Thanks. ^_^
Since you are chasing numbers you gotta be careful with the correction factor and dyno in question.
I've been down this road before about 5 years ago when there were less options out there.
I think the smoothing was 0 and the correction was set to SAE for that run. The aux ports were wired open here as well.
Anyway I had a street port with T2 rotor housings, which eliminates the diffuser in the exhaust. That does make the exhaust noticeably louder and more harsh though. The manifolds were port-matched. Exhaust was an RB header, test pipe, and 2.5" RB catback. Intake was basically a "hot air intake" with a cone just sitting there.
Engine management was an SAFC. Rtek was not available for nonturbo engines back then. If I could do the build again, I would
1) use an Rtek 2.1 for fuel and timing control
2) Quiet the exhaust down because it was so harsh, especially when I had dual Apex'i N1 rather than RB. I would have used a cat or an n/a exhaust sleeves because they are quieter and have smoother flow.
3) controlled the aux ports with a factory air pump, a converted rats nest solenoid, and the switched output from the Rtek
I've been down this road before about 5 years ago when there were less options out there.
I think the smoothing was 0 and the correction was set to SAE for that run. The aux ports were wired open here as well.
Anyway I had a street port with T2 rotor housings, which eliminates the diffuser in the exhaust. That does make the exhaust noticeably louder and more harsh though. The manifolds were port-matched. Exhaust was an RB header, test pipe, and 2.5" RB catback. Intake was basically a "hot air intake" with a cone just sitting there.
Engine management was an SAFC. Rtek was not available for nonturbo engines back then. If I could do the build again, I would
1) use an Rtek 2.1 for fuel and timing control
2) Quiet the exhaust down because it was so harsh, especially when I had dual Apex'i N1 rather than RB. I would have used a cat or an n/a exhaust sleeves because they are quieter and have smoother flow.
3) controlled the aux ports with a factory air pump, a converted rats nest solenoid, and the switched output from the Rtek
You can tune an RTek pretty effectively on the street if you pick up a wideband O2 sensor and controller. Not really very difficult. The RTek logging is effective. You can tune it to about 12.8-13.4 across the range at WOT. Before you go to the dyno, create a couple maps that are a bit richer and a bit leaner everywhere in the band, and corresponding ignition maps with a couple levels of additional advance. Then do a few runs on each map. You'll very quickly find out where the car wants to be richer and where it wants to be leaner, as well as where your optimal ignition point is.
I personally wouldn't touch the intake. I will do some back to back runs with the stock airbox and with a "hot air" intake using a cone filter this spring but in all honesty for an NA, the stock airbox flows plenty of air and is a very effective cold-air intake.
Make sure your 6-ports are working. Don't take the easy way out and wire them open.
Spend money on a good header.
Ignition won't do much for you if anything.
Don't bridge the aux ports. It just doesn't do anything. If you're tearing into the motor, a street port would be worthwhile. Otherwise, don't bother.
Finally, don't get too hung up on making "numbers." Mod the car to the extent you're comfortable and focus on improvements. Your car might dyno 170whp on one dyno and 150whp on the next. It just depends on too many factors. Get a good baseline on one dyno and return to that dyno for your follow-up runs. There will still be some uncertainty, but at least you'll know basically where you stand.
I personally wouldn't touch the intake. I will do some back to back runs with the stock airbox and with a "hot air" intake using a cone filter this spring but in all honesty for an NA, the stock airbox flows plenty of air and is a very effective cold-air intake.
Make sure your 6-ports are working. Don't take the easy way out and wire them open.
Spend money on a good header.
Ignition won't do much for you if anything.
Don't bridge the aux ports. It just doesn't do anything. If you're tearing into the motor, a street port would be worthwhile. Otherwise, don't bother.
Finally, don't get too hung up on making "numbers." Mod the car to the extent you're comfortable and focus on improvements. Your car might dyno 170whp on one dyno and 150whp on the next. It just depends on too many factors. Get a good baseline on one dyno and return to that dyno for your follow-up runs. There will still be some uncertainty, but at least you'll know basically where you stand.
Joined: Mar 2001
Posts: 31,837
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From: https://www2.mazda.com/en/100th/
just to piggy back on that, the peak number with stock ecu VS not stock ecu won't change too much, but the non stock ecu will have a much broader power curve.
Thread Starter
'84 RX-7 GSL
Joined: Aug 2004
Posts: 266
Likes: 0
From: Tulsa, Oklahoma
Making numbers wasn't a goal... I've just ridden with someone with around 180hp in his n/a and loved the feel of it so I was trying to get a baseline of how to reach somewhere around the same.
I've had mentioned to me using the rx8 stationaries on this build... you guys think it's that necessary or should I just stick to some "hardened" s5 stationaries?
I'm taking all of you guys' information you're giving me all in and appreciate every bit of it. Thanks
I've had mentioned to me using the rx8 stationaries on this build... you guys think it's that necessary or should I just stick to some "hardened" s5 stationaries?
I'm taking all of you guys' information you're giving me all in and appreciate every bit of it. Thanks
bro you don't need **** for stationary gears. I'm running s4 stationary gears on a heavily modified turbo engine. If you've got the engine apart do a street port. Also if you are willing to do so, convert to s5 intake manifolds.
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