Rennlist Discussion Forums   classifieds | membership | rennlist | photo album    
sponsors | upload photo | chat    
 
Go Back   Rennlist Discussion Forums > Water Cooled Technical Discussion Areas > 924/931/944/951/968 Forum
Sign in using an external account
Register Forgot Password?
Search


Reply
 
Thread Tools Search this Thread
Old 05-04-2003, 01:11 PM   #1
stoked944
User
 
stoked944's Avatar
 
Join Date: Dec 2002
Location: Columbus, OH.
Posts: 329
Send a message via AIM to stoked944
Post 944 vs. rx7 turbo 2

ok my friend wants to get a second gen. mazda rx7 turbo 2. does anybody know how these compare in handling to a 944. i told him that a 944 would handle better but he doesn't agree. neither of us have driven one. also how does the power of the rx compare to a 951. i think this is a great battle between two cars. what do you guys think.

but i would still pick my porsche.
To remove this ad, register today or login if you already are registered!

stoked944 is offline   Reply With Quote
Old 05-04-2003, 01:15 PM   #2
streckfu's
Necromancer
Rennlist Member
 
streckfu's's Avatar
 
Join Date: Jul 2002
Location: Moving back to the '50s.
Posts: 63,710
Daniel Streckfuss Streckfu2U2
Post

It depends on the condition of the two vehicles in questions. All things being equal, the 944 is probably the better choice (if it's 85.5+).

The RX-7 seem to have longevity issues unless meticulously maintatined (like ours don't). The rotor engine is famous for producing huge amounts of heat that shorten the engines life.

Besides, the torque on the rotory engines leaves a lot to be desired.
__________________
Daniel

I am luckier than I know.

The concept that the Bill of Rights and other Constitutional protections against arbitrary government are inoperative when they become inconvenient or when expediency dictates otherwise is a very dangerous doctrine and if allowed to flourish would destroy the benefit of a written Constitution and undermine the basis of our government.
- Justice Black, Reid v. Covert, 1957
streckfu's is offline   Reply With Quote
Old 05-04-2003, 01:40 PM   #3
Scootin159
Super User
 
Scootin159's Avatar
 
Join Date: Oct 2002
Location: Syracuse, NY
Posts: 3,088
Post

The rotory engines have a life expectancy of about 200,000 miles, at which point the rotor just wears out no matter how well it's maintained. They also have little torque and poor gas milage.

Handling wise they are very similar. The 944 does have better handling, but the RX-7 isn't far behind.

I actually have a video comparing a 924S to the RX-7. They RX-7 did win, but it was really close, and judging from what the guy said it was mostly just because of the 924S's high price.
Scootin159 is offline   Reply With Quote
Old 05-04-2003, 02:13 PM   #4
SoloRacer
Addict
Rennlist Member
 
SoloRacer's Avatar
 
Join Date: Jun 2001
Posts: 3,147
Post

I actually own an 87 Rx7 Turbo 2 as well as a 89 944 Turbo. I bought the RX7 as a track car and drive the 944 on the street. I believe there is a thread on this forum that had a comparison between the two cars. As far as my own comparison goes here is what I have found so far:

Handling & Braking
My 944 Turbo has the M030 option and when my RX7 Turbo was stock I noticed that the 944 had a harder ride, exhibited less body roll and had far superior brakes. The steering on the Porsche felt heavier than the RX7. On the track the brakes on my RX7 would fade considerably over 5 laps whereas I have never had my 951 brakes fade - even when they were hot and screeching. The RX7 comes with a psuedo rear wheel steering system that I did not care for. When pushed hard in the corners the rear will try to "steer" giving the driver the sensation that the back end is about to swing around and put him in a spin. It was not something I was comfortable with. Fortunately the aftermarket has a set of bushings that eliminates this feature (DTSS Eliminators) and once installed the car felt far more predictable.

Stock 951 w/M030 VS. Stock RX7 Turbo - Winner is 951 however there is a lot of aftermarket support for the RX7 that can be used to build it up to the 951 level and beyond.

Power

My 951 is a Turbo S model and stock it has about 60 hp more than the stock RX7 Turbo. The power delivery however is very different. Power on the RX7 comes on quickly with minimal turbo lag. The 951 has signifigant turbo lag but when the power does come on it has a lot more oomph than the stock RX7.

Build Quality

No comparison, 944 all the way. It has no rattles or squeeks and feels like it is built out of a solid chunk of steel. Not so with the RX7.

I'm a member of a small RX7 club with guys who have modified their cars. My 951 is also modified (280 rwhp/307 ft lbs torque on a Mustang Dyno) One of the guys is making about the same power as me but with less torque. His car is quicker off the line and it takes me some distance to pass him. Another friend is making 370 rwhp with a massive T04E and I take him off the line and when he finally gets spooled he blows me away. The guys with stock T2's or N/A's really don't compare.

I would like to say one thing about the RX7 though. The rotary engine has a bad reputation for being fragile. They do make a lot of heat but contrary to what was said that is not what shortens the engines life. The cooling system is designed to handle this heat. I was seing EGT temps of 900 degrees celcius and had no problems. Only if you overheat does it affect the water control seals and ruin the engine. I had this happen once because it turned out that the radiator that was put in my car by the previous owner was plugged 1/2 way down. The NA rotary engines that are racing in the Spec 7 series here run forever and have minimal problems.

The biggest problem with the rotary is detonation. They cannot take much detonation and thus if you are playing with fuel mixtures, timing or increasing boost you have to know what you are doing or else you risk detonating and ruining your engine. When an apex seal is damaged or blown by detonation you are looking at a major rebuild. Swapping the exhaust on a turbo RX7 and porting can net huge power gains. Fuel Cut Defenders, Super AFC's and other piggy back units are commonly used to try and get safe mixtures. Most who have gone this route ended up blowing motors and learned that the only way to go is with a stand alone. The most popular one with the RX7 crowd is the Haltech E6K.

I would take my RX7 Turbo over an NA 944 any day as once I got used to the turbo I could not go back. Most N.A. 944's I have driven felt slow in comparison with almost nothing that could be done to give me the power I desire. However, I would not trade my 951 for a second gen RX7 - even the highly modified RX7 that my friend has. He is making more power for less money but I still enjoy my 951 way more. I think a fairer comparison to my 951 would be a 3rd generation RX7. Regardless of which car you get you should have access to a good shop or expert you trust to maintain the car. Because the rotary engine is unique with few people who truly understand it you should especially make certain you know someone who has modified and knows the car inside and out.

Good luck!
__________________
Current Fleet:
2001 Lotus Turbo Esprit V8 400+ HP
1973 Volvo P1800 ES - 125 HP
1994 968 Turbo - Kelly Moss Racing - 479 HP/550 lb-ft
1993 Acura NSX - Supercharged - 350 RWHP
1993 RX7 Turbo - 255 HP
1989 951 Vitesse Stage III - 303 RWHP
1977 Toyota Celica
1973 914 - Sheridan Body
1953 Kaiser Manhatten
Ferrari F355 Challenge Car 390 HP
SoloRacer is offline   Reply With Quote
Old 05-04-2003, 02:20 PM   #5
SoloRacer
Addict
Rennlist Member
 
SoloRacer's Avatar
 
Join Date: Jun 2001
Posts: 3,147
Post

Scootin: Ahhh...no. The rotor does not wear out. It's the apex seals that get worn and lead to low compression - not the rotors. This is similar to the rings on a piston engine wearing out over time. I have never heard of a 200,000 mile life expectency on a rotary engine. It is misinformation like this that people have used to degrade the rotary engine and primarily comes from people who do not understand them. I have a Honda with less than 200,000 miles (280,000 km) that is using oil and needs a rebuild. My 951 had an engine rebuild at 81,000 miles because of a scored cylinder wall. Yet I know guys with NA RX7's that have over 200,000 kms and have minimal problems. All engines wear - piston or rotary.

You are correct however about the fuel consumption. My RX7 has horrible fuel mileage even when compared to my 951.
__________________
Current Fleet:
2001 Lotus Turbo Esprit V8 400+ HP
1973 Volvo P1800 ES - 125 HP
1994 968 Turbo - Kelly Moss Racing - 479 HP/550 lb-ft
1993 Acura NSX - Supercharged - 350 RWHP
1993 RX7 Turbo - 255 HP
1989 951 Vitesse Stage III - 303 RWHP
1977 Toyota Celica
1973 914 - Sheridan Body
1953 Kaiser Manhatten
Ferrari F355 Challenge Car 390 HP
SoloRacer is offline   Reply With Quote
Old 05-04-2003, 02:56 PM   #6
Mledbetter
User
 
Join Date: Jul 2002
Location: Modesto, CA
Posts: 271
Send a message via AIM to Mledbetter
Post

I'll chime in here...

I currently have a 3rd gen rx-7 and a '87 951. I also had a '87 Turbo II for a while and was lucky enough to have all 3 in my driveway for a couple of months.

Daily Driver'ness - The Turbo II is a much better daily-driver, followed by the 951 and then the 3rd gen rx-7. I would put the 3rd gen as number 1 if it wasn't for my 6'3" / 225lb frame.

Straight-Line performance - I never took the '87 rx-7 to the strip, but I think the new owner has managed to clip off a very high 13 second run. 13.8 or or 13.9 at Sac Raceway. It's got an exhaust, intake, and a ELP chip in it. Stock it ran consistent 14.9/15.0 at 90'ish. It's easier to launch than a 951 by far and feels "peppy" even with the torque disadvantage.

Around town, the Turbo II feels quicker than a 951. In reality, it probably is quicker up to about 50-60mph under most conditions. My turbo II, even with mods, got about 20mpg in the city. Better than my 951.

Brakes, hands-down to the 944, 951, etc

Reliability - I agree that most well maintained 2nd gen rx-7's will approach 200k miles. As with any car, modifications will bring down the life a bit. My 3rd gen has 100k miles, the last 60k running at close to 350rwhp with no reliability issues.

Aftermarket support - rx-7

My 2 cents...

-Matt
Mledbetter is offline   Reply With Quote
Old 05-04-2003, 03:54 PM   #7
SoloRacer
Addict
Rennlist Member
 
SoloRacer's Avatar
 
Join Date: Jun 2001
Posts: 3,147
Post

Matt,

I love the 3rd gen RX7 and if one comes available at a good price I will probably be buying. What mods have you done to yours?
__________________
Current Fleet:
2001 Lotus Turbo Esprit V8 400+ HP
1973 Volvo P1800 ES - 125 HP
1994 968 Turbo - Kelly Moss Racing - 479 HP/550 lb-ft
1993 Acura NSX - Supercharged - 350 RWHP
1993 RX7 Turbo - 255 HP
1989 951 Vitesse Stage III - 303 RWHP
1977 Toyota Celica
1973 914 - Sheridan Body
1953 Kaiser Manhatten
Ferrari F355 Challenge Car 390 HP
SoloRacer is offline   Reply With Quote
Old 05-04-2003, 05:51 PM   #8
Mledbetter
User
 
Join Date: Jul 2002
Location: Modesto, CA
Posts: 271
Send a message via AIM to Mledbetter
Post

I've had mine for about 3+ years and absolutely love it. I've considered picking another one up for a daily-driver, but I always flip-flop on what type of car I want to drive. I put 55k miles on it in the first 2 years, so it has been pretty reliable.

Off the top of my head...

downpipe, midpipe, catback
greddy FMIC W/ pipes
Efini Y-pipe
Apexi Power FC ECU W/ datalogit
Upgraded fuel system
HKS Twinpower
RP Underdrive pulley set
M2 lightweight Flywheel / ACT clutch
Blitz boost controller
B&M Shifter
Feed Strut Bar
MazdaComp Radiator
Upgraded brakes
Full suspension

I probably missed a few things, but thats all I can come up with. I'm still torn between going with a single-turbo kit or the new upgraded twins from BNR.

If you find one in good condition, I highly suggest picking one up. It's hard to beat the bang for the buck.

-Matt
Mledbetter is offline   Reply With Quote
Old 05-04-2003, 06:04 PM   #9
joseph mitro
Super User
 
joseph mitro's Avatar
 
Join Date: Apr 2002
Location: Oklahoma
Posts: 2,834
Post

it's been 8 years since i owned a 1990 RX-7 na. can't compare the turbo models, but i agree with what's been said so far. the mazda does handle pretty well although the road feel is much better and handling is overall better with a 944 or 951. speed - i think a rx-7 turbo would be faster than most 944s unless it's an S2 or a 951. still, with rx-7 prices for the 2nd generation being low, i wouldn't hesitate to buy one.
joseph mitro is offline   Reply With Quote
Old 05-05-2003, 12:06 AM   #10
GOBOGIE
Budding Photographer
Rennlist Member
 
GOBOGIE's Avatar
 
Join Date: Jun 2001
Location: A Quiet Little Lake In The Middle of Nowhere
Posts: 6,873
Post

Yeah, I saw that top gear video comparing the 924s to the Rx-7 (second generation). Good comparison. I loved my '87 Rx-7.
__________________
GOBOGIE is offline   Reply With Quote
Old 05-05-2003, 01:34 AM   #11
Brett
Addict
Rennlist Member

 
Brett's Avatar
 
Join Date: Nov 2002
Location: Parker,CO
Posts: 826
Post

951 vs. rx7? 951 wins hands down! I just raced an rx7 second gen. this last week. His was modified and he got a good start, however, I got a terrible start but caught up to him when I hit third gear. If we had more room I would have blown his doors off.
Brett is offline   Reply With Quote
Old 05-05-2003, 01:34 AM
Rennlist



Paid Advertisement
Reply

Tags
350rwhp, 944, 968, car, fuel, ii, make, power, problem, reliability, reliable, rx7, stock, track, turbo

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump


All times are GMT -3. The time now is 01:36 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
SEO by vBSEO 3.6.1
Copyright ę 1998 - 2007 Rennlist.com

Advertise on Rennlist - Privacy Statement - Terms of Service - Jobs