Alright I have this friend of mine who thinks all firebirds are white trash. Hes getting an MR2 and I know that i'll have no trouble beating him. His brother on the other hand has a 94 Rx-7. He has done nothing to it. My car had pretty much nothing. I have a K&N air filter, performece water pump(it only cost $5 more then the normal one)and by the time we race i'll have headmen headers, flowmasters, Slp cold air intake, and hopefully 3.73 gears. After all those mods do you think i can take the RX-7. and how do you think i would do against him without any of those mods?

 

If you have all of those things (although the 3.73s seem kinda high for tpi car, but maybe thats me.) you will definantly get him out of the hole and maybe for the 1/4 ( i believe they are good for a mid to low 14 with a good driver, but anybody that gives up the wonderful twin turbo wankle for an mr2 obviously can't fall into this catagory), but anything after that and you are toast. The cars make around 255hp and 215ftlbs of torque at some amazing revs (6500 and 5500 respectivly) and are around 3200 fully loaded (driver, full tank of gas ect) so he has a weight advantage and once he gets going he has lots of revs to play with and a fair amount of power. Then again if he short shifts it and never gets the turbo's spooled or the wankle really up and spinning then you could easily have him.

 

Yeah I kinda think that those gears are a little high but that’s what a lot of people recommended. And they all seemed like they knew what they were talking about. What do you think I should get instead? Mabey 3.23? Thanks for your input I appreciate it.

 

IMO go with 3.42's unless you plan to do a motor swap with a carbed motor then got 3.73's.

 

for an auto car id do 3.23's (G92) and a 2,800 lock up TC
5 speed 3.42's (G92) would be all i want
the TPI is all about low and midrange power..GM used the 3.23's and 3.42's for a reason...they exploit the TPI's "qualities"...Using more gear will put the motor higher in the RPM range, exactly what you DONT want to do..
Dont get me wrong, going from a 3.23 to a 3.42 in an auto car will no doubt make it faster to 30 or 40, cut you some better 60 ft's, but when the motor cant breathe up hi to begin with, you add more gear to it...that be halarious to watch it fall all over itself BEFORE half track lol

ok you didnt say what year your ride is..that makes a big difference...

depending on your car and the options it has, it could run a 14.6-8 to 14.0-2 in stock form...With the mods you "plan" on doing, theres an easy 3-4 tenths in that stuff (including the K&N)

Theres no way that little MF'er will be anywere close to you untill after 80 MPH (your 2-3 shift)...after that, hope he lets off lol...

take all your RPO codes and put them in in the RPO decoder on the main page...

 

If the RX-7 is still running on both turbos, then you will have your hands full.

They are REALLY easy to launch, and take off like a jack rabbit on the street. Practice your launch, because with the 350 and 3.73 even decent tires will lose significant traction. Don't run from a roll.

 

What gears do you already have, 3.27s or 2.77s? If you've got 3.27s screw it they're fine. If you've got 2.77s you need better gears, but you're kinda limited on options and it'll cost alot being a 9-bolt... I'd just try to score some used 3.27s from another 350 car, or maybe the whole rear end to save on paying someone else to install the gears...

You'll take the guy with all the mods IMO. Might even be able to take him with 2.77s still... Unmodified they aren't that fast. His is a 5spd right, I can't remember if they offered an auto (seems like they did at some point on the newer style RX7s)?

 

My car is a 1989. I already have(im pretty sure) 2.77. I know for a fact that im getting those parts. Ive been saving up and christmas is on its way. I've raced this ricers that rev at me. and ive beat them all. Of course alot of them do fly bys thinking they win. Thats alright though i kno im faster. So after all those mods do you think it would be safe to say I might have him. This guy talks major **** and i would love to put him in his place. He said all third gens are white trash, and i'll be lucky if i dont break down because thats all American cars do. I just really want to show him whats up. Also on a side note, he said he wanted to race for pink slips, i would never ever do this but thats how stupid he is. Oh and he wanted to put money because im a waste of gas. yea whatever

 

you should pm rx7 ***** boy he knows everything about his wankels

 

What kind of RX-7? There were many different engines. There was an N/A one, a single turbo and a twin turbo. You definitely need to find out that information before racing him. You will be killed if it is twin turbo and you don't race from a stop. I believe the TT ones run low 14s to high 13s stock.

~Matt

 

That year only had a twin turbo so that pretty much solves that issue. Anyway american cars break down? Ha! show me a wankel with 180K+ like my the 350 in my dads suburban that hasn't been rebuilt atleast once and probably twice. Wankels are nice and i would love to have one of the last twin turbo models or the new rx8 (i know its a little ugly, but its not a bad engine and after driving a 4cyl bmw and an s2000 i have a spot in my heart for high revving super 4cyls and such, right next to that spot filled with tire smoke from torque monster V8s and up) but they have issues with the seals on the rotors wearing quickly. You buy an rx7 with 100k and it hasn't been gone through you are in for some money. Any way its off topic, grab some 3.4x, make damn sure you have the posi to go with it and get him off the line and you should be ok up the 1/4 after that its his race.

 

LOL, he should talk. Browse your local autotrader or something and check out the number of 93+ RX7s that have something about "new motor" or "blown motor" in the add or mention mileage on the new motor. Last one I did that in no lie had near 50% with hosed/replaced motors. Pretty unusual for cars that aren't that old...

 

hahaha i know it. There was this civic wiht something crazy like a 150 shot of nitrous. He beat all of these cars and then on the way home his engine blew up. also these cars rev to their rev limiter and think it does nothing to the car. The rev limtier is there for a reason. I guess they dont kno that

 

i donno
a stock FD (93-95) I think can cut 1.9-2.0 or around that range

depending on driver a stock one can be around 13.8-14.5
0-60 can be from around 4.8-5.6 range again on driver
cars have a decent amount amount of power even down low since the turbos are of two different sizes

first one starts to spool almost right away then I think at around 3800rpms the second one kicks in for even more air flow

so even at 80mph I'm sure it will be close race and even down low don't think the camaro will just take it like that from a rx7

all in all though I say drivers race unless one of you guys does something very different to the car

 

93-95 also known as thirdgens or FD is ONLY twin turbo

from 86-91 you you have the second gen series
known as FC also or S4 from 86-88 and s5 for the 89-91's
in 87 they came out with the single turbo unit here in the states

then you also have the firstgen which is known as many different namesfrom I think 79-85

 

how many would you like me to show you

if ou wish I can go out and take a pic of my odomoter if you like at 199k on the clock

and if you really like I can show the picture at a little over 7krpms as well

the rotary motor isn't that bad and I don't mean to offend you by this but before you talk about how unreliable the rotary motor is go and find out more as to why it is so bad and you would find out that the motor itself isn't that bad and actually quite reliable


PS. with the compression test I did I expect at least 250k before she quits

 

yeah the FD was a problem child
a lot of it though was caused by the lack of cooling the motors get
the front facia didn't let much air in to cool the rad
the twin turbos generated a lot of underhood heat
the radiator is very small and would be lucky to cool a geo metro going down hill at 95.3 miles an hour

the fuel system wasn't that great and close to being maxed out

they used a MAP system which doesn't do very well when you start changing things or the temps get a little different and when you boosted HAHAHA...

vac lines popping off or breaking with the heat the TT makes

a intercooler that was a joke being it h ad no real direct air flow

ppl who think add more boost means go faster
BOOM!!!! forgot to make sure it had the fuel and tuning to handle it...

starting to see a trend here?

 

bout time you got a wiff of your wankel and posted on this

 

hey I post every now and then

but this place has slowed down a lot so only come here everynow and then or when I need to

 

Settle down bud... We are talking about the 3rd gen RX-7 here, not your N/A car. The N/A versions lasted about as long as a piston engine, but the TT cars were on borrowed time after 60K. I can't tell you how often we replace engines on the 3rd gen cars here at the Mazda dealer I work for. Not to mention how many turbo setups we replace. And the prices!

Somehow I knew you'd show up. You never seem to miss an RX-7 post

And to whoever mentioned the auto being available in the 93+ cars: Yes, it was. In VERY limited numbers.

 

"Ha! show me a wankel with 180K+ like my the 350 in my dads suburban that hasn't been rebuilt atleast once and probably twice"

My Trans Am has 180,000 miles with no rebuilds, just the mods I did. The tranny has never been rebuilt either. Thanks RX-7 for the info on the cars. Should be helpful.

~Matt

 

both cars being stock it should be a pretty close race. If your going to do gears 3:73 work very well. Eric

 

should post more often so we can have more wars

 

yeah I am around


hell the thirdgen in itself was limited

only 14000 +/1 about 700 where shipped to the US

as far as the thirdgen yes they do tend to go out at about 80k

but also a lot of that isn't the fault of the motor

mazda needed to get everything else up to par to take stress of the motor and they didn't

chances are running many other cars under the same situation as the FD went through I doubt they would be the longest lived car either



and sorry about getting up tight with the mile thing

a lot of ppl hear rotary and think 20k is all your going to get out of them, that the burn oil real bad, or one of the MANY falsehoods about the rotary that go around

hear those things one too many times

 

you sure?

the 350 is already chocked with the stock TPI system
using 3.73 on the stock TPI unit would bring the rpms up after the shift point prolly causing the car to choke

 

Bingo. 3.42s are as steep as you should go with the stock intake system, 3.23s might even be just as good. A 4500 rpm redline doesn't go very far after all, you'll be out of your powerband before you can blink with 3.73s in a choked off tpi system. You could fix that problem pretty cheap and easy with a carb though.

 

Yeah I’m getting 3.23 gears.

 

3:73 dont chock a car with stock TPI. I was running 13.83 with stock TPI and stock engine internals with my 3:73's. Which is a very respectable time for a basically stock TPI car. After installing my super ram , and lower intake with Drag radials the car runs 13.50's. this is a car with stock heads and cam. i used to have 3:27's in the car and the car went .23 sec. faster with 3:73 then with 3:27 with the stock TPI. so theres the proof.........Eric

and yes i'm sure

if you need more proof click on the link below for video

 

There is a heck of a lot more to E/T than simply the E/T.

It's NOT debateable as to whether 3.73s spin you out of the powerband of tpi too fast because they do. TPI was designed with a 305 in mind and it barely breathes well enough for that application breathing normally before choking at 4500 and basically having NO power at 5500, with a 350 it breathes even worse, probably around 4200 before it starts hurting performance.

Sure RPM "ruins people's motors" but that's EXACTLY why 3.73s are too much for TPI. 3.73s would probably be great for a dedicated 1/8th mile racer but on the street and in the 1/4 3.73s would be detraumental to your overall performance.

Unless you have an intake that can breathe better than the stock restrictive TPI piece (even siamesed ported etc etc) you're going to be killing your performance with 3.73s.

This whole debate is moot as the person who was interested in gears in the first place already made the wise decision of purchasing 3.23s.

 

INwo, the proof hurts......as for tpi being designed for low end RPM power yes. as for a totally stock TPI car only pulling to 4500 RPMs ,yes but with full exaust on a tpi car 5000 RPMs is not a problem. 3:73's are not a radically step gear for the street. the tpi does well with the very low rpms and the 3:73's work very well to help upto 5000-5200RPM's with stock heads and cam. as for my car being killed from the high rpms i've been street/strip racing it since 1989. If you read what i wrote above you'd see that my car went .23et and 3mph faster in the 1/4 when i switched for 3:27 to 3:73 with stock TPI. this was all BEFORE I installed an aftermarket TPI setup. have you ever you ever done a 3:27/3:73 comparison in you car? I have and theres the proof! I've only scene a very few people on the boards turning ET's and MPH in the 1/4 like me with STOCK Heads/Cam so maybe if you don't know what your talking about you should be more open into paying attention to people who have done the comparision. It's not like i said install 4:11's or 4:56's there just 3:73. like i say if you need more proof theres a link

 

You have proved nothing. You're only assuming that the gear change gave you better e/t not weather etc.

3.73s WILL NOT HELP PERFORMANCE ON A STOCK TPI SYSTEM, IT WILL HURT PERFORMANCE.

Maybe you should look at all the people who went slower in their tpi equipped cars before making the broad assumption that 3.73s will help everyone? I know you're the fastest guy on the board with 13.5s but that doesn't mean you're correct. I know a person who went from 3.08 to 3.73 gears on a fully ported stock system with a custom tuned chip who went .4 slower with only the gear change. No amount of further tuning helped.

I know, I know, you want to justify your foolish purchase of a gear that will hurt you in the long run just so you could burn your tires easier and get worse fuel mileage, that's cool, that's your thing. However, for people who are interested in maximum performance out of their TPI system 3.42s are the biggest you should go. Have you looked at a dyno graph for where the torque and hp peaks are on stock tpi? I doubt it but I'll let you know that just after the peak is when you should shift. Yea, you CAN spin it up to 6000rpm no problem, will it be performing better or worse? That's right, it'll perform worse.

I guess people who make purchases without being educated on how it will actually affect performance, doing a ton of mods at once and then saying that the "key" was a certain mod have to justify the expense somehow. It's hard to argue with logic like that because no matter what evidence you present it won't be enough because "I ran soooo much faster after dropping 2k on this new wing!" Can't argue with that!

 

heres 2 cents buy a clue.....end of story

 

WOW your argument is compelling and insubstantial at the same time. Your technical knowledge obviously surpasses my own, good day to you!

 

There are a lot of things that could have effected your ET, temperature, prep of track, how much you ate and if you took a dump before racing.

Noone is willing to take your word for it, cuz your wrong. Gearing has to do with setting the operating range of the motor within the powerband. If your gonna jump up and tell us you have the magic TPI motor that revs til 6k, well, your stupid. end of story.

Tire size, gearing, transmission gears all effect performance. There is no magic gear number that works with everything. Its specific to your combo. 3.73 may work well with a 30" tire for a TPI car, but put a 26" tire on there and you'll run out of gear.

The Admins here have been nice enough to put some gear calculators in the tech area. I recommend you visit there, with your dyno sheet in hand (assuming you have an idea of what your powerband looks like on your current setup) and figure out exactly what gear, with what tire size you want. Make sure you know your tranny gears too.

-- Joe

 

Thats very nice that 3:73's helped you, I would have to say that is more the exception than the rule. Most people cannot benefit from this change alone. Most people can't even put the torque they have with 2.73's to the ground, let alone with 3.73's. You should be suggesting suspension, tire, traction mods. Like I said glad that worked for you. It is not the magic bullet for every 3rd gen. Its sort of like adding nitrous, adding it doesnt neccessarily guarantee you will be faster automatically. It can help but not unless a few other things are taken care of at the same time or subsequently.

BTW If memory serves me correctly that RX7 was only a 10th off a ZR1 that year the new RX7 debuted.

 

anthesthes -if you would have read what i types above you would see that i shift my car 5000-5200 RPM. no where did i state that i shift at 6K. no magic there so maybe your stupid not me,maybe read before ya type next time? it's pretty funny that you cant accept that my car ran faster with 3:73 then 3:27.the 3:73 keep the car right in the power band,like i said before i shift at 5000-5200RPM's Your idea that i didnt eat much that day makes much more sense.just curious have seen a car with 3:73's go slower or are you just using your calculator?

TomB4C1- your right 3:73 on a totally stock car might not be the first mod to suggest. I was stating in my case that my car picked up afew tenths. while other people say that it's impossible for a car with stock heads and cam to do such a thing...lol...well it did. I'm just trying to show the improvement that they had on my car. Just seems that afew people would rather call me a liar.

 

First of all, if my car went 13s I'd shoot myself.

Second, yes. I've seen plenty of people overgear because they heard a certain gear was great.

What size tires are you running? What was your 60'? Was your MPH the same on each run? I wonder if the 3.73s are making you go slower now. E/T is not a good measure of anything. I can make a 14 second, or a 12 second pass both at the exact same MPH..

-- Joe

 

maybe the 3:42 would have been better then 3:73 but all i know is i knocked off .23 and gained 3mph when i changed from 3:27 to 3:73. If you guy chose not to to take my word for it,thats your right.anyway in it's current form it runs 1.900 60' 13.59 @ 101.36 thats on BF Drag radials 16" rim

 

You want to cross the traps in 1:1 gear just past your peak hp. Simple as that. If 3.73's helps him do that, then obviously it will help make him faster. End of story. If I recall correctly a stock 350 tpi makes it's peak power at 4400 rpm, which should raise with breathing mods. I found a graph with an almost identical setup to his for comparison.
https://www.thirdgen.org/techbb2/sho...ghlight=dynoed
Now assuming he peaks around 4800 rpm, he should be shifting a little past 5000, really around 5200 or so, in order to stay in his power band the best. So he traps at 101 mph which would put him at about 4300 with 3.27's, 4500 with 3.45's, and 4800 with 3.73's. This is ofcourse with a stock tire size of about 26 inches. With all this info, I doubt he overgeared.

 

Here's a mildly modded tpi 350: http://chuckb.1le.net/archive/past_c...350_dyno1.html Notice peak torque is around 2700, notice peak hp is around 4200. Sure, you can rev it til it absolutely falls flat on its face if you want. It's up to you. You can get a 2500 stall with your 4.11s and cross through the traps at 6k if you want, cause sure it'll rev that high, you just won't be making any power. An aftermarket intake will help the motor breathe, but with the stock intake ported or not it will not breathe well over 4500. It is confusing that it doesn't seem to get through to some of you. It is general knowledge. Anyone KNOWLEDGABLE about tpi will tell you that. Jimbob the mechanic at the local oil change place might tell you that it's not true but anyone who has worked with tpi and seen more than one dyno graph will tell you this. How about this, go ask on one of the tech boards and see how many of the well versed members tell you the same thing. I'd wager a CLEAR majority.

 

some people simply don't believe in math. I found a dyno graph of a setup almost IDENTICAL to the person you accused of overgearing. That graph shows he peaked at around 4800 rpm. I find it funny you can even tell him he overgeared when he is one of the fastest bolt on 350 tpi's here, lol.

 

Some people don't believe in reading threads before posting in them. I find it funny you think that every setup that has similar parts will produce identical results. You're telling me that with a stock intake 3.73s isn't overgearing? Let me quote what the entire argument is about.

Ok, now read what that says. Stock intake. Did you get that? That means he overgeared. Perhaps you'd like to review the dyno of the bolt on tpi 350 with the stock intake again? Perhaps you'll note that it falls off drastically after 4400? No? Take a look again, see it now? Oh that's right, you can't read, "lol."

With an aftermarket intake 3.73s don't hurt him as bad provided his heads and cam support it. Stock TPI intakes are spun out of the powerband too quickly by 3.73s. This would particularly hurt on the street as after burning the tires off the power would disappear too quickly to ever win a race. 3.23s or 3.42s are a better gear for the street.

 

Also, he won't drop out of his power band as much, especially with the 700r4's large grop from first to second. Take me for instance. On my bone stock L03 I dropped .5 off my et and gained close to 4 mph just by shifting at 5,000 rpm rather than 4400 all on a car that supposedly peaks at 4000 rpm with the crappy swirl port heads. Shifting at 4400 simply took me out of my power band too much.

 

wow man, such disrespect from a fellow moderator. I "can't read," ok. I'm reading your crap right now oh tpi ***. Do you actually think I'm going to look at that 1 single graph and take it as gospel? For every graph you post like that, I can jsut as well back it up with another one that pulls much farther than that. 4200 rpm is absolute crap! Hell, bone stock they peak at 4400 rpm and you will want to shift past the peak once again. Since you wanna be so rude, I'll do some more math to prove you wrong. A stock 350 tpi will trap in the mid 90 mph area, lets just say 95 mph. Now with a peak of 4400 rpm bone stock. Now at that speed in 1:1 gear you would be trapping at about 4000 rpm with 3.23 gears, about 4200 with 3.42's, and about 4600 with 3.73's. Once again, math proves you wrong. 3.73's look nice again.

 

does that mean 3.73 is the best gear?


have you tried 3.42 or a 3.55 gear?

that might make a little bit of difference


also have you dyno tested your car to prove your claims with the powerband not falling off till after 5000+rpms on the stock intake manifold?

also how many times did you run each gear?
driver/weather conditions can make quite a difference in times also

too many variables so in reality there is no PROOF

 

The proof is in his et's. If the 3.73's hurt his car like people claim he simply would not be as fast as he is. I find it extremely amusing that he is able to go faster with his "overgeared" 3.73's than most others are with a higher gear ratio.

 

Tell me how your math works out in a practical application. How many people have YOU seen that went consistantly appreciably faster with 3.73s than 3.42s especially on the tpi board? How many actual verifiable repeatable real world testimonials have you seen? I'd wager that number hovers around "well this guy in the thread right here said..." Bad advice is bad advice and recommending 3.73s to the average guy driving the average mild bolt on TPI equipped car is BAD ADVICE. There are too many variables to account for a small change in mph when at the same time drag radials are used. Heck, the mph increase could be accounted for by a bit of tire spin and who knows the temperature could have been cooler resulting in a bit better e/t, there is no clear answer in this case.

ON THE STREET (which is what we're all interested in on the street racing board anyway, right?) 3.73s are a terrible gear for tpi. Traction with a higher than stock stall and cold tires is non-existant. This means you will NOT win many races on the street stoplight to stoplight and you might as well forget about highway racing completely. 3.23s and to a lesser extent 3.42s are much better gears for the street. It will allow the car to be in the powerband much longer resulting in better success on the street. If you have a dedicated drag car you wouldn't be running a 700r4 anyway, you'd have a good transmission such as a th350 or th400. If you're running a 700r4 you're probably interested in gas mileage and there's another spot 3.73s lose.

This is way off topic and I'd suggest that this be taken to another board such as the TPI or drivetrain board if you're actually interested in learning something regarding gearing a TPI equipped car.

 

ok same thing as I was saying to someone else

peak hp doesn't move the car it doesn't matter what your peak hp is when going through the traps

as a lot of ppl here will agree it is torque that moves the car
and no hp doesn't keep the car moving that is still torque (getting tired of this write up is comming)

and gearing can make for more torque
but looking at that car's dyno graph the real powerband only seems to be 3200rpms to 4600rpms

and you want to keep your car in that portion
also if you are wanting to run for maximum performance you would be best to keep in the MEAT part of the torque curve which on the car you pointed out seems to be 3200-4400 most the time

that is where most of your moving force is once you get out of that it starts to drop


remember hp doesn't move your car torque does



one other thing

that dynosheet you pointed out the guy is using a superram
which should flow quite a bit more then the stock TPI setup

 

yes, I realize he has a superram, and the guy they said overgeared has a superram as well.

anyways, this will be my last post on this thread seeing as how much bs is in it. Before I leave I would like to point out how much of a load of crap you just said is. Try telling that to anyone who actually does race. I would like to provide to you a dyno of a stock tpi system on a 305 that runs mid 11's and pulls well past 6,000 rpm. You will also notice he shifts well past 6,000 rpm, even close to 7,000 rpm where he has virtually no torque at all, yet for some unknown reason he run's 11's with a 305 no doubt. I could find many more instances where this happens, but I won't waste my time.

https://www.thirdgen.org/techbb2/sho...highlight=3.73

 

as inwo and I said super ram makes quite a bit of difference as far the rpm range

did you see the dyno that inwo pointed out notice how quick the torque drops off

at that 4800 rpms you talk about that puts you almost 75lb/ft less torque then peak

you want to stay in the meat section once again and try not to get out of that meaty part of your torque badn