dsm vs rx7

[danielbui]

I dont know too much about rotary engines, but i am sure they are a hella expensive to rebuild. Not many people out there are extremely familiar with rotary rebuilds (dont rotarys have no pistons.... Im' so lost on this subject).

www.racingbeat.com go there on the cover page is a triangle with a hole in the middle. this is what is used instead of pistons. it spins instead of thrusts. based on the same principle.

www.rx7.com is another site to visit.

 

[GVR4592]

I dont know too much about rotary engines, but i am sure they are a hella expensive to rebuild. Not many people out there are extremely familiar with rotary rebuilds (dont rotarys have no pistons.... Im' so lost on this subject).

If you don't know anything about rotaries then why are you claiming that you THINK they are expensive to rebuild. They are no more expensive to rebuild than a piston engine.

Rule #3 No Guessing - if you don't know the answer, don't reply - bad advice can be worse than no advice (no "I think" or "I guess" or "I've heard").

A rotary engine doesnt have as many parts as a piston engine, and it's not that complicated.

Prices for the best rotary engines (in my opinion) http://www.pineappleracing.com/PricelistSvcs.html

 

[Malero5]

It's based on one simple fact...... only one company makes rotary engines. It's basic economic principles..... Someone who has worked on a lot of rotary engines is gonna be a lot harder to find then someone who has worked on a 2.0L engine. Around here there is only one reputable rotary engine shop and with first hand experiance they were crappy. (They used to work on my old subaru and they gipped me 200 dollars because they got my window to work. They didnt fix anyhting...so when it did finally take the full crap I just replaced the brushes in the little power window motor and it worked.) When you have no competition for your business you can charge more. But you are correct.... I know almost nothing about rotary engines. I was just giving my .02 cents.

 

[assa 98gsx]

I would get a DSM if you want to race straight. Funny that 2 days ago, this guy owns a RX-7 decided to race me from a stop. He has a 93 twin Japanese HItachi turbos and blew his differential from the launch.. I am pretty sure a DSM can take a bit more abuse than the RX-7.

 

[Dimcorner]

1. Rebuild kit is about 1200 including all seals

2. More than likely you need to machine the apex corners of your rotors to 3mm from 2mm (yeah they are thicker and hold more power however at high rpm they WILL float a little)

3. You better find someone to do it for you cuz you absolutely DONT wanna mess up. (if you do you have to take the WHOLE engine apart and replace ALL the seals again)

4. to make 320whp is easy and reliable if you dont' beat it off EVERY STOP LIGHT and do the right mods (14psi, upgraded ecu, fuel pump, FMIC, full exhaust, radiator) Notice no injectors and no upgraded turbos.


to break down the price for 320whp...

PowerFC - 1k
FMIC - 1k
radiator - 300
fuel pump (supra drops in) - 150
full exhaust - 500
ported motor (give you a good 10-20% hp) - 4k

the motor is optional, but you might as well go for it. A stocker will run you 3k so for 1k more you can have a good port job on it and 3mm seals.

my car did 320whp with all of the above running stock factory turbos running sequential spooling. so i start building boost at around 2k and get full at 3-3.5k.

 

[GVR4592]

If you wanna push 400 hoarses on anyhting below a 2.5 liter you are looking at a racing engine..not a street one. This means your spending a lot of money. I am rebuilding my laser and its gonna cost me 2k in parts and 1k in machine shop work just to make somehting that can handle about 380 WHP for 60k miles. These are small engines..... if you wanna run huge HP then you need to put slack in your pistons, which leads to a car that wont run more then 25k miles. If ya dont put slack en em then you are looking to seize up your pistons in no time.

None of what you said is accurate. A 400 hp 2.0 liter engine isnt classified a race engine because it has 400hp. I have hit over 400 WHP on a stock engine and I know theres people out there that have had over 500 WHP with a stock engine. Is my daily driver a race car? Not hardly. Putting slack in the pistons? I'll assume you are talking about piston to wall clearance. The clearance varies depending on the piston manufacturer, because they all use different alloys. Nobody takes their engine apart when they hit 380whp to give the pistons more clearance. It's not neccesary. The stock engine can handle 380whp easily, there is no reason to build an engine to handle that power level.

It's based on one simple fact...... only one company makes rotary engines. It's basic economic principles..... Someone who has worked on a lot of rotary engines is gonna be a lot harder to find then someone who has worked on a 2.0L engine. Around here there is only one reputable rotary engine shop and with first hand experiance they were crappy. (They used to work on my old subaru and they gipped me 200 dollars because they got my window to work. They didnt fix anyhting...so when it did finally take the full crap I just replaced the brushes in the little power window motor and it worked.) When you have no competition for your business you can charge more. But you are correct.... I know almost nothing about rotary engines. I was just giving my .02 cents.

Your basic economic principles are wrong. A rotary engine doesn't cost any more to rebuild than a piston engine. Your bad experience with a shop and lack of knowledge of rotary engines doesnt mean that they are some kind of voodoo engine that nobody knows anything about.

If you go to Aut x's you will notice that miatas,911's, and rx 7's usually dominate in the stock/street modified classes. In autocross its all bout handling and mostly low end torque.

All about low end torque. Yeah those cars are torque monsters.

 

[danielbui]

are some of you getting the 2 mixed up? i hope not because there is a HUGE difference. they are based of the same type of racing but one is alot less MPH than the other.

the best cars i have seen on Autocrossing were the newer MR2, MRS, AWD Porsche, karts, kit cars (mid engine rwd or awd). alot of turbo cars stock will light up tires when boost kicks in. some have good times and others just need to get used to the course and there cars and get the drift mentality out of their heads. funny thing is the girls are alittle faster.

 

[Malero5]

I wanna see you rev up your 400 WHP car to 8,500 RPMS everytime to punch it It wont last more then 10k miles.

Lets see you push 400 WHP on a 2.0 liter and have it last more then 30k miles (Granted to run passes at a drag strip...if you dont use the power then why have it)

Ummmmmm notice how all those cars were NA except for some of the rx 7's? Notice how the rx7's push very little boost? Ill bet you anyhitng a 2.3L stroker with a 14b running 12 pounds of boost will smoke any 2.0 20g. Driving a big turbo in auto X is damn hard. Anyhitng that has a lot of kick all of a sudden (NO POWER AT 3K RPMS as in no low end torque at all) is hard to keep control of. Go to your local auto X...... you wont see many "Turbo" monsters. DSM's were made for the drag strip. Granted a 16g AWD with a good suspension will do well

 

[planblars]

I can't believe no one has brought up SP engineerings Supra7 rx-7 body with a completly built 2jz i think it made like 1100whp I would kill to own this car

 

[mirkoelek]

IIIIIIIIIIIII ------------for dsm
IIIIIIIIIIIIIIIIIIIII -----for rx7

 

[Defiant]

Fix that hood and I'd be interested.

 

[99gst_racer]

Fix that hood and I'd be interested.

Yeah, the hood is ugly as sin, but at least it's functional. The cowl vents under-hood heat, and the passenger side scoop directs air directly to the turbo; sort of a ram-air affect. If it were my car, I'd still shop for a better looking hood though.

 

[planblars]

they actually made the hood for the car because there was no hood available at the time that would have room for everything to fit under it.

 

[slipstream808]

I'd take the RX-7 over a DSM if it weren't for the motor issues, and the back end coming around. It's an amazing car. Just realize if you do get one... get a good oil cooler and radiator, give it some good preventative maintenance, and dear god GET RID OF THE TWIN TURBO!! Jesus, that is as necessary as the radiator. Then be prepared to rip into the motor eventually. It'll prolly need work. The motors are "finicky" unless it was well maintained, had a better cooling setup put in it, and wasn't boosted. Basically, unless you are buying from a person who could teach you about the car, then expect work. Get a spare motor and some parts.

Now as for the "back end" thing... EVERYONE should do this with their new car. Take it to a big ass parking lot where you can get it up to 50ish, and have nothing to hit. Then just freaking floor it!!! Corner it, drop it, e-brake it, whatever. Experiment here! You can learn safely where the breaking point is. Granted there aren't all of the various corners and road conditions here... but it'll help a LOT.

Unless you have the $$$, take it easy on the car. Be prepared for a rainy day, and have another car to drive. Other websites and RX-7 forums have a lot better stuff and info than this website, cause it's RX-7 specific. And remember, pay attention to the good stuff too, cause they will mostly be posting car problems (like this site).

As for a DSM... well we turbo both cars, but with a DSM, I'd be much more willing to run high boost and on a "ragged edge" than an RX-7. Plus I'd be willing to boost MORE OFTEN with a DSM, than an RX-7. Daily driven... the DSM would be more fun IMO.

Do and LS1 swap, and you'd be very set. Great power, not the reliability issues.

And as always... the more money you have for it, the better it will be. Have fun and make the right decisision

 

[Spartan302]

Rx-7 with an LS1.....

 

[mirkoelek]

what is ls1

 

[Spartan302]

what is ls1

Its the motor out of the late model camaro's and firebirds.

Click here. You get the handling and weight of the rx-7 but eliminate all the reliability problems with the rotary motor.

 

[spyderturbo007]

I have owned both, a 87 Turbo II and now a 97 Spyder GS-T. When I bought the Turbo II it had 71k on the clock and the motor had never been opened. I didn't do any upgrades to the RX and never had a problem (I was in college and poor at the time).

The only problem I ever had with that car was the tranny. Around 100k the syncros went out in 2nd and 3rd gear. I got one from a junkyard and swapped them out.

When I got out of college 4 years ago, I sold the RX to a good friend of mine (120k). He still has the car and hasn't had any problems with it. Last I saw him it was up to 185k.

As far as the Spyder, I haven't had any problems with it (knock on wood). I realize that you are asking about the 3rd gen RX's but I thought I would post this up anyway.

My recommendation, go with the RX. They are sweet looking and handle like they are on rails ! I just wanted a convertable.

 

[Dr Stone]

I currently own both a 94 Rx7 heavily modded(365rwhp) and a 90 GST Eclipse. I can honestly say that in the last 6 years that I have owned both the 7 has been more reliable. I have had so many tranny, electrical, valve seal and various problems with the eclipse than I care to list. I should have had a town truck punch card to get the tenth tow free or something. The 7 had one major down time where yes the engine blew a apex seal but that was 2k then back on the road. Well im not knocking the DSM its a nice little car but Id never trade my 7 for another DSM ever.

There is just something about the 7 that once you have one for awhile and get the "its a rotary and will break all the time" mentality out of your head you will love it. As for working on the cars, its alot harder to work on the DSM. Mine is down right now and wont start. The diagnosing is tons harder on the DSM. I do all my own work includeing changing engines in both cars as the timing belt broke on the DSM and killed the valves so I just changed the whole engine cause I had a spare. Anyhow it wont start and I cant figure it out.

Get the Rx7 but you better be prepared to do alot of research and dont be afraid to work on it yourself cause alot of shops dont know how to and just say they dont like it as in this thread.

L8r
Jeremy

 

[mirkoelek]

I currently own both a 94 Rx7 heavily modded(365rwhp) and a 90 GST Eclipse. I can honestly say that in the last 6 years that I have owned both the 7 has been more reliable. I have had so many tranny, electrical, valve seal and various problems with the eclipse than I care to list. I should have had a town truck punch card to get the tenth tow free or something. The 7 had one major down time where yes the engine blew a apex seal but that was 2k then back on the road. Well im not knocking the DSM its a nice little car but Id never trade my 7 for another DSM ever.

There is just something about the 7 that once you have one for awhile and get the "its a rotary and will break all the time" mentality out of your head you will love it. As for working on the cars, its alot harder to work on the DSM. Mine is down right now and wont start. The diagnosing is tons harder on the DSM. I do all my own work includeing changing engines in both cars as the timing belt broke on the DSM and killed the valves so I just changed the whole engine cause I had a spare. Anyhow it wont start and I cant figure it out.

Get the Rx7 but you better be prepared to do alot of research and dont be afraid to work on it yourself cause alot of shops dont know how to and just say they dont like it as in this thread.

L8r
Jeremy

thanks man

 

[mirkoelek]

what about street leagl rx7 ls1??????????????

 

[Spartan302]

what about them. they are street legal. go to rx7club.com and read up there. you'll get a lot more info then on the dsm board.

 

[mirkoelek]

what about them. they are street legal. go to rx7club.com and read up there. you'll get a lot more info then on the dsm board.

so you are saying mazda with ls1 can pass emission testing

 

[Malero5]

Just not in cali. There are also a few places that check your engine to make sure its the same as the one that came with your car. Other then that...its all about testing the exhaust. If you have a standalone engine management system you will have no problem tuning it down. Here in Idaho we only get the exhaust test. Ive seen hundreds of cars with engine swaps pass, aslong as everything is ok and it isnt an open exhaust.

 

[definitiveno]

AWD>RWD



















just in case no one said that yet