Automatic RX-7 - Performance Issues-
Ok, I have a 94 automatic (tell I can find a manual in good shape) and have some questions about the performance of the automatics.
Speed is by far no problem at all, but it is a dog out of the hole! It just creeps along after I nail the gas for about 30 or so feet, then Bam! turbo hits and it takes off like it should. I have tried manipulating the shifter (with Hold on and with Hold off) and it still is very sluggish off the start, I have been told that it is just the bummer about the automatics, If so I might look at getting a manual sooner that I had planned. I love the car so damn much, I never thought a person could love a car, like I love my 7, So if anyone has had a similar problem, or if a solution is available please tell. BTW- I'm relatively new to the RX-7 world, I have wanted one ever since High school when the 3rd gen's came out, and had to wait tell I graduated College before I could buy one. I have only had mine for about 9 months, so please keep responses with a "newbie' in mind :) |
using the HOLD button is the place to start - But use L+Hold to start in first because S or D + hold both start off in second
Also add a (If your still stock) DP, open up your intake and add a K&N - your turbos will spool quicker The main reason the Auto's are such dogs off the lin is that they are stuck with a 3.90 ring & pinion set vs the 4.10 in the manual, and the auto first gear ratio is almost as high as second in the 5spd. Also the OD 4th ratio is higher than OD 5th on the 5spd - 3rd auto & 4th manual are = @1:1 and 2ond auto is in between 2&3 manual I don't miss a 5spd during my daily comute to/from Santa Barbara/Ventura CA - The auto is so much eaiser in heavy FWY traffic. :cool: |
Thanks for the info. Once I'm rolling with HOLD in L and my RPM's are around 2.5k I have no prob taking off like a rocket, but from a dead stop or at a stop sign stop....I will definitely look at the K&N (whatever they may be :) Any resources where I can read about it?
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My brother just got his '93 FD auto back from KDR. It spins the tires by just flooring it in 1st gear at 10psi. He has performance tires. PFS PMC, racing fuel pump. dp, mp, cat-back, big IC, 1200 cc injectors. Imagine what it will do at 15 psi and high octane fuel.
Ken |
I too am in love with my car, which happens to be an automatic. And I feel your pain. A Geo Metro can get the jump on a Auto FD, its quite humbling.
The main culprit being that power robbing, overgeared MPV minivan transmission they stuck in the Rx-7 as an afterthought. As someone earlier pointed out the ring & pinion gears on a Automatic are 3.90:1, Swapping this out for a 4.33:1 set will help your off the line performance and overall performance as well. Problem is its pretty spendy. $450-500 for the parts and figure 6-7 hours labor, that brings you close to $1000 I guess if your really trying to keep costs down you could find a parts car and pick up a used 5spd rear end (4.10:1) Mod wise, it could be a smart move, because it doesn't effect other aspects of your car and require dumping money into more mods. I will probably do this mod at one point also. I've heard it makes a big difference in a Auto FD. Plus you can still use it if you swap your auto for a 5spd later on. |
BTW Sloraxe,
Kick Ass website....You got some SERIOUS skills!:bigeyes: |
Switching out tranies? I have talked to a mechanic about this, and it seemed like a hell of a lot of work...I couldn't imagine doing all the mod's that LUV94RX7 talked about, the stock FD is awesome enough I might look into some small mods that will help out with the take off...Still wondering what a K&N is.
Thanks about my site, I'm a web designer by trade. |
K&N is a brand of air filters. They're made out of cotton fiber with a coating of oil; stock air filters are typically paper. The K&N filters are much less restrictive, so will help your motor breath easier. They are also re-usable, you can buy a cleaning solution and replacement oil. The filters are guaranteed for 1 million miles, or some ridiculous amount. Even if you don't want to get a full on cone filter, you can get just a straight replacement filter. I've used them on several cars, including my commuter car (Kia Sephia) and swear by them.
Oh yeah, here's the K&N website |
get a apex pfc and a torque converter from level 10 with 3500 stall. you will spin the tires from a stop...you might have gotten a better response in the 3rd gen section rather than the tech support section. i wouldn't waste my time on the swap. find a manual if that's what you want. take the money you save by not having to swap and dump it into the engine. also look here...https://www.rx7club.com/vforums/show...hreadid=40115. feel free to chime in, lots of auto owners love their cars, me included:D
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OK, thanks for all the info. I just ordered the K&N Filters (air and oil <running and 2500 miles need to change soon<).
Are there any other "easy" mods that can be done to the car to improve performance from a dead stop? I would also look at any one or 2 heavy (or expensive) mods if they DONT do any damage to the car, I do not want to accelerate the wear of parts...to much. |
I have my auto unitl I find a nice R1. So far I'm impressed how fast it is. I can't wait until I drive a manual! ;)
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It is all in technique.....
Once you understand the limitations inherant with the automatic, you can minimize the down side and take advantage of the good side... First of all....a downpipe is such a must, it is not funny.....the difference in the car is pronounced, running a dp. Second is opening up the airbox, I prefer the "thrifty man's airbox mod" as detailed on the Robinette site. This is a true "cold air" intake mod, that does not detract from the form and functionality of the rest of the intake system (in my opinion). But back to how to drive the thing once you have the intake and exhaust not so restricted...... Ok, all of us auto owners know the drill, you slam the gas pedal, the car goes, "What? Oh....yes....YES...GO NOW!" and what that means is that at about 30 yards from where you punched it, all of a sudden you have a snarling handful of turbocharged fury, not exactly where you were expecting it! My car will break the tires loose at this point, often, rather than at the "line", so to speak. So, in order to get the jump right AT the line (because you will STILL smoke most anything a few yards DOWN the road) you need to power-brake a little bit. Just left foot brake and bring the revs up. With practice you can get some ROCKET like launches.... :) But I don't like to do this, I just usually prefer to let the other guy have a BRIEF moment of glory, thinking he was beating you, and then waste him a second or two later, when the power comes on....it is all the same, a win is a win. |
Bajaman, I just want to be 100% clear as to what your technique is. This is what I gather from your previous message.
You are on the line with some n00b Mitsubishi or Mustang owner. You hold down the foot brake with your left foot while you rev you car to the proper rpm with your right foot. When the light changes, you remove your left foot and accelerate with the right foot accordingly. Is this correct? Can this also be done in hold mode? |
ok like he said do exactly that, but run it in L with hold down..it should work great but dont forget to let go of the hold button before u get to redline...about 6700rpm
hehe i got a auto to!! |
Originally posted by Sloraxe Are there any other "easy" mods that can be done to the car to improve performance from a dead stop? In theory an automatic-equipped turbo will be faster than a manual, because the torque converter doesn't just slip... near its "stall speed" (appx. the max RPM that you can brake-torque it to) it also MULTIPLIES the torque, not sure on the Mazda trans but it's typically around 1.7-2.5:1 multiplication... so in fact there is more torque multiplication than a 5-speed in first gear. 300ZXTT automatics were quicker 0-60 and 1/4mi than the 5-speed model! |
Hey Call Your Mother Peejay!!!!!
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I had this same problem on my 91' NA that USED TO BE an automatic. I cured the problem by dropping in an 87 TII 5-speed tranny and swapping for an 87' TII diff. and had a 4:30 ring and pinion set compressed into it. I love my car way too much to let a tranny "problem" get in the way. :) Good Luck,
Derek |
Ok, I'm not going to power break my car, its just not meant for it. But I can not live with a car this dead off the line, I find myself trying to switch cars with my wife and drive her Eclipse (running Cat back, DP and a few other trinkets).
Anyway, If I can find some mods that will cost me less then 2k Id do em just to improve the launch speed. I'm looking into a DP and exhaust for it, get a apex pfc and a torque converter from level 10 with 3500 stall |
Just so you know, although I don't think it is a bad idea to get them, a DP and catback will probably not help your low end much if at all.
-Derek |
Well some possible good news/bad news. I dropped my car off at Independent Mazda in care of Larry Scott, and he tells me that some of my vacuum hoses going to my "low end RPM" turbo are busted, witch would account for the tremendously slow launch speeds. Well I'm replacing all those lines now with some performance lines, and very very excited to get my car back mid this week.
though I have always wanted a 3rd gen I think I'm going to put mine up for sale in the next few months and shop for a 5 speed. I curse the man who ordered this car from the dealership with an auto! But who knows, I still love the car, maybe I can talk my wife into letting me just buy another one :) I already have convinced her that I need a "project car" and to let me buy an 88-91 T2 to mod up, I need some wrench time to learn these cars better. |
Originally posted by Sloraxe though I have always wanted a 3rd gen I think I'm going to put mine up for sale in the next few months and shop for a 5 speed. I curse the man who ordered this car from the dealership with an auto! But who knows, I still love the car, maybe I can talk my wife into letting me just buy another one :) I already have convinced her that I need a "project car" and to let me buy an 88-91 T2 to mod up, I need some wrench time to learn these cars better. Like I said before. If you're SERIOUS about improving the off the line performance and overall performance, then your only choice is getting 4.33 gears and maybe an upgraded stall converter. I found a website once (still looking for it again) where a FD auto owner installed the 4.33 gears and took detail notes/measurements of the before vs after effects. He already had dp/cb/intake and commented that the 4.33 made the biggest performance gain yet. He highly recommended it if you had a auto FD> Do you have a boost gauge? If not..thats the first thing you should get. |
Yeah, installing a boost gauge and a Turbo Timer this month. And looking to do intake next month.
If you find that website let me know, I would totally be interested in reading more on that gear conversion. I also read on the forum to switch to a Level 10 Torque converter with a 3500 stall... |
Ya boost gauge is a must. I bought mine without one. Slapped one on and found my primary turbo was only making 6psi, secondary was barely 3psi.. I thought "Oh God" I just bought a lemon.....Come to find out the main cat was plugged. Had it gutted, and been 10-8-10 ever since :)
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Isn't it true that all FD's came w/o a boost gauge? BTW, Sloraxe....how much would you be looking to get for your car? If you still want to sell in a few months that is....
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BTW, Sloraxe....how much would you be looking to get for your car? |
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