1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

T2 or cosmo 13BTT swap? i need your opinions.

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Old 08-10-05, 02:22 AM
  #26  
1983 GSL, 1987 323 "GX"

 
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Okay, let's put it this way.

Brakes and suspension will get you MUCH farther than the motor as far as track use (not really, but that's what I like to say )

Basically, it really is better to upgrade suspension/brakes (BRAKES! Did I say brakes?!) before motor/power stuff.

I advise brakes before anything else, as they likely need replacing anyway.

Since you have a 79, you PROBABLY have rear drums.
On the contrary to what the 'tuner' companies want you to beleive, this is NOT necessarily a bad thing. Since you're such a new driver, I'm assuming you'll be using this for daily transportation rather than for track use. Therefore, your rear drums are BETTER, as they last MUCH longer and have a negligeable performance drop as compared to discs.

Your front discs should be replaced or turned. Replace them with OEM discs, as you won't see enough of a performance gain from vented discs (and you'd see ZERO gain from crossdrilled!) to warrant the cost/trouble.

As for the pads, replace them with HAWK pads, as those are VERY nice pads.

As far as the suspension, as far as I know, you've selected a GREAT package to upgrade to. I have tokico struts on my car, and it handles very well.

If you DO intend to progress to Autocross or Track Racing, the next upgrade you should look at will be your tires. Get some cheap, all season radials for around town (I'm sure it rains plenty in PA, and it's smarter to have some 'foul weather' tires than JUST racing tires which offer NO safety in the rain!)

After that, you can probably start on the performance mods. The quickest way to gain power would, of course, be to swap in a turbocharged model. This is NOT the ONLY way, though.

First, and before anything else, get yourself a stronger Fuel Pump, and a Fuel Pressure Regulator. I'd advise a Carter.

After that, put some mechanical secondaries on your car, or, better yet, send it to Sterling or Carl to have them upgrade it.

This should give you a noticeable power gain.

Next after that would be a free flowing exhaust system. My setup is the full Racing Beat setup, head to tips. I love it. Others would advise doing something from Magnaflow or another company. To each his own I guess.

After that, set yourself up a Cold Air Induction system. Go from the headlight opposite the battery. Funnel it to your Air Cleaner.

Vent your brakes after that, using similar methods. (Front is best )

Finally, you can port your motor. By that time, after all the other mods, a good streetport will be getting you around 160 or so horsepower, which is very decent.
A bridge will easily push you over 250, if I'm not wrong. Torque won't be too far behind, unlike if you had turboed the motor.
Old 08-10-05, 02:24 AM
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1983 GSL, 1987 323 "GX"

 
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Holy sheep ****! That's a long post!
Old 08-10-05, 05:27 AM
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The Gen 1 was designed for 100hp, modifying with 200+hp can make the car a real handful except in a straightline. I have raced some powerful cars over the years but still get surprised how quickly the RX-7 rear end wants to break away on a curve. The rear suspension is a poor design dictated by costs.

My car with 220rwhp in the wet becomes very twitchy under acceleration. and a drift car while cornering That's even with a full suspension upgrade and top tires. Thus, you definitely need some experience to handle a very powerful gen 1.

As for your original question, in the long term I would go 13B Twin Turbo but only use one large turbo. Go to the forum site to look at the advantages and options available.

There were several good write-up on this forum about a 13B TT set up some 3 years ago by Mike-P-28 which you should read.

Last edited by PaulFitzwarryne; 08-10-05 at 05:31 AM.
Old 08-10-05, 06:59 AM
  #29  
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Welcome tothe forum

First as several other members have said get your suspension, brakes, and tires sorted. this will take some money regardless of how you do it, and you and the car will last a lot longer if you do these first.

then when you have gotten adjusted to what the car can do, handleing and braking wise, you can consider upping the ante on the power side. upping the power without working on the handling and stopping is begging for a totaled car.

depending upon how you plan on using the car, a simple suspension and brake pad change might be all you want, but on the other hand, maybe you want a fully adjustable suspension from the shocks to the sway bars to the trailing links, just depends upon its intended useage.

kenn
Old 08-10-05, 08:13 AM
  #30  
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just do the swap then kick your self in the *** later when alot of problems occur, then after 1-2years think about how you almost gave up on the project and almost wrecked and think about how it was all worth it...then while you are still day dreaming you accidentaly run into a tree(but not hurt of course!) EEK!
Old 08-10-05, 08:51 AM
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my advice is to do your brakes first, tune the car up and then leave it alone. you can't go wrong with good (or great) brakes.

my thinking is since you're still green, you should learn to drive the car and sew the seedlings for your relationship with the car first. while you're doing that, you can get a feel for what you want out of suspension. i'm saying this simply because it would seem more efficient to do something only once. if you get the Racing Beat suspension setup now later down the line when the addiction bites you, you WILL hook up with other Rx-7 owners and you may drive someone's car and find that the $800 suspension you bought is not what you want.

however, with that said ... i echo the sentiment of doing the suspension before you move on to engine and power upgrades. you will truly find out how amazing your car is with 100 HP.

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Old 08-10-05, 09:51 AM
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wow. this is the best info ive ever gotten out of any thread. thanks a lot guys! i really appreciate it!
Old 08-10-05, 10:08 AM
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ok, i found cross-drilled and slotted rotors on ebay for $100 shipped (set of two). they are made by Rrotorz. has anyone ever heard of them? are they a good company to buy from? im asking beacause racingbeat sells powerslots for $248 a set. and if these arent good brakes to get, does anyone know where ican find OEM brakes? and how much they will be? thanks.
Old 08-10-05, 12:00 PM
  #34  
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Man I just quickly read through this post. A few comments...

1. the shop that does the swap is that just for labor? For a 13bt swap you are looking at 3k in parts and that is for a non-rebuilt JDM.

2. If you are just taking your drive test wait a while. I am sure that you are going to want a car to show off to all your friends. If you do a swap you are looking at a fair amount of down time depending on how dedicated you are.

for the 13bt look at a 3-4k price range and 13btt 5-7k price range. IMO both these estimates are fairly conservative since possibilities are endless on modifications/setups!

I remember when I first started to drive. I drove around a 1970 Ranchero. Oh yeah that is right I drove a cruck! It was plenty. The 125 rwhp that I have is plent and I agree with the person that spoke about the rear end. It does get loose! And in the rain can be a little cumbersome to drive. That is why mine is a fair weather car ony though!
Old 08-10-05, 09:18 PM
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thanks for the info. yes, the $3500 is just for labor. i guess its a bigger job than i thought. they have to make a wiring harness, set up the fuel injection, pull my engine, put the new one in, make sure everything works, etc. but is $3500 too much? i figured its a fair price because no one around me really messes with rotaries. there is a place about 1 1/2 hours away, but they gave me a $11600 estimate for a T2 swap with 200-300 hp, depending on what i set the turbo at. they only do rotaries, and are known for being one of the best rotary specialists, so i guess thats why its so expensive.

but anyway, can you guys tell me anything about those Rrotorz brakes for $100 shipped?
Old 08-10-05, 10:03 PM
  #36  
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Originally Posted by rxtuner79
thanks for the info. yes, the $3500 is just for labor. i guess its a bigger job than i thought. they have to make a wiring harness, set up the fuel injection, pull my engine, put the new one in, make sure everything works, etc. but is $3500 too much? i figured its a fair price because no one around me really messes with rotaries. there is a place about 1 1/2 hours away, but they gave me a $11600 estimate for a T2 swap with 200-300 hp, depending on what i set the turbo at. they only do rotaries, and are known for being one of the best rotary specialists, so i guess thats why its so expensive.

but anyway, can you guys tell me anything about those Rrotorz brakes for $100 shipped?
And you can probably count on $3-7k for parts depending on the type and condition of what you want--from used stock parts to new high performance parts. Mine was about $3500 and I did all the design and labor. That includes a fresh rebuild for about $1500. No way I was gonna drop in a used engine without knowing its condition.

Personally I like the Cosmo 13B-RE. If I had to do it again, I would have went that route. The only thing I'm not to sure about is whether it is difficult to get parts for that engine, being that it is not used here in the US. If the other rotary parts will work OK and you can get the parts you need, I'd go with the Cosmo. I'm sure some other members can chime in about Cosmo parts...

Scott
Old 08-10-05, 10:15 PM
  #37  
1983 GSL, 1987 323 "GX"

 
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Don't go with those brakes. For one thing, as I've said before, you'll just end up replacing those cross drilled rotors TWICE as fast.

I've also NEVER heard of this company. Beware.

You will NEVER need slotted OR crossdrilled rotors, unless you're running a heavy car at extreme speeds ALL the time. Except under those conditions, slotted or crossdrilled are simply visual flair. With good pads, all you need is OEM discs.
Old 08-10-05, 10:46 PM
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listen to jays83gsl ... stock rotors, Hawk pads, stainless/Teflon lines, good synthetic, high temperature fluid. check the master cylinder (or replace if necessary), proportioning valve, make sure that BOTH calipers and BOTH drums work. that's all you need.
Old 08-10-05, 11:35 PM
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jays83gsl definitely seems to know what he's talking about. i just havent seen any OEM rotors and stumbled into these while searching ebay. does anyone know where i can find OEM brakes?

EDIT: also, i am trying to find an '82 rear assembly for when i do the turbo swap, so i will probably wait until i get that to upgrade the rear brakes. and i found rotors on mazdatrix. OEM front rotors are $199.62, but aftermarket rotors (doesnt say which brand) are only $63.39. should i go with the aftermarket brakes?

Last edited by rxtuner79; 08-10-05 at 11:41 PM.
Old 08-11-05, 12:20 AM
  #40  
1983 GSL, 1987 323 "GX"

 
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Diabolical hit the nail on the hammer or whatever.
If I'm not wrong, Racingbeat has some stainless braklines in the $50 range?
Old 08-11-05, 12:36 AM
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for OEM stuff, i either look to Mazdatrix or Mazdaformance. However, you can check your local chain auto parts retailer (Advance, Autozone, etc., etc.) for their prices and availability.
Old 08-11-05, 12:52 AM
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Alright, basically, you get what you pay for.
I advise going to Autozone or Checker or Kragens or whatever and seeing if they have the DURALST brand available for your car. I've never been more pleased with an OEM replacement brand of rotor. I'm sure I'm the only person with DURALAST stickers on his car

As for the rear upgrade, as I've said before, it's mostly unneccessary. The difference between the rear drums and discs is negligable. At least, it was on my 323 when I swapped discs in. I'm sure it's NO different for the RX7. I've never driven a rear drum RX7, though, so I can't tell you

The only real reason to swap to the GSL rear assembly is the Limited slip differential, and recent research has shown me that that was actually sort of rare, even in GSL models.
Old 08-11-05, 12:52 AM
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i saw rotors at mazdatrix, but like i said above, the aftermarket are cheaper than the OEM. it doesnt say the brand name, so im not sure which ones to get.
Old 08-11-05, 12:57 AM
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Originally Posted by jays83gsl
Alright, basically, you get what you pay for.
I advise going to Autozone or Checker or Kragens or whatever and seeing if they have the DURALST brand available for your car. I've never been more pleased with an OEM replacement brand of rotor. I'm sure I'm the only person with DURALAST stickers on his car

As for the rear upgrade, as I've said before, it's mostly unneccessary. The difference between the rear drums and discs is negligable. At least, it was on my 323 when I swapped discs in. I'm sure it's NO different for the RX7. I've never driven a rear drum RX7, though, so I can't tell you

The only real reason to swap to the GSL rear assembly is the Limited slip differential, and recent research has shown me that that was actually sort of rare, even in GSL models.
like you said, i mainly want it for the LSD, but i cant just buy that. i have to get the whole assembly. also, when i do the T2 swap, i would like to have a stronger rear end.
Old 08-11-05, 01:05 AM
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Good idea, but that should be rather low on your list of priorities.
Of course, if you find a striking good deal on one, then JUMP!

Call up Mazdatrix and ask them what brand the generics are. Also ask them what kind of warrantee they come with. If they have at least a 2 year warrantee, they should last quite some time if there's PADS on your brakes

Old 08-11-05, 01:17 AM
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damn. what the hell happened to that? anyway, ill probably give them a call tomorrow and find out.

this thread went completely in the opposite direction it started in, but im glad because i had no idea how involved everything else could get.
Old 08-11-05, 01:25 AM
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THAT is what happens when you run brakes with insufficient pads. Hence the sentence above the picture. That and I like showing off my atrocity of a brake

It didn't go OPPOSITE, just in a different direction.
Old 08-11-05, 10:10 AM
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if i can get a complete rear from an '83 gsl, including the driveshaft, for only $200, should i do it? i can drive 40 minutes to go see if its in good condition.
Old 08-11-05, 10:28 AM
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I would opt for the gsl rear for the lsd, but the motor should be a 13bt. You don't need an rew nor do you need the hassles of having one. A stock 13bt with aftermarket exhaust and intake will boost you up to almost the same power as a stock TT, but getting the TT stuff to fit and work properly in an FB would be a hassle that you wouldn't want. It would be cheaper for a 13bt as well, I got mine for $650 with tranny and complete longblock. Came to $1050 shipped from canada to my door (-$100 if you ship it to a shop). Japan star motor is where I got it from.
Old 08-11-05, 12:45 PM
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IIRC the rear discs actually had worse stopping times. When I was looking into a rx7 a few years back I was shocked to see that the drums actually had better stopping distances. Granted that this is on a totally stock setup. Not sure how the hawk pads would perform.

As far as the rew engine I partially agree with gerbraldy. Yes it will be more expensive and yes it will be a little more volatile. However there will not be fitment issues. People have commented that the TT's hit the passenger side etc but quite frankly that is BS. I spoke with a guy that actually did the setup and is running the twins. He had no problem with the fit. I am not sure about the cosmo engine but they are based off a fairly similar platform so it should work. When it comes down to it there is not a huge difference in performance(IMO) that you cannot achieve from a bt. I have seen over 500hp setups on a bt.

How much hp/tq do you want and how much money do you have, that is the question.

~Z


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