Why did mazda chose to go sequential?
01-22-10, 12:20 PM
#1
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Why did mazda chose to go sequential?
Giving all the engineering hurdles, budgets, and reliability issues...it seems like a big waste of money and time.
Was it simply so they could say "we did it!"
Perhaps just a marketing scheme?
Far as I see it...
Seq = faster spool less power
Non seq = slower spool more power
Is the slightly faster spool really worth the hassle?
I'm really curious as to WHY Mazda choose to make the worlds first production sequential turbo setup?
Was it simply so they could say "we did it!"
Perhaps just a marketing scheme?
Far as I see it...
Seq = faster spool less power
Non seq = slower spool more power
Is the slightly faster spool really worth the hassle?
I'm really curious as to WHY Mazda choose to make the worlds first production sequential turbo setup?
Last edited by TwinTurboSC; 01-22-10 at 12:26 PM.
01-22-10, 12:26 PM
#2
You're forgetting that the Eunos Cosmo had sequential twins back in 1990 (20B and 13B-RE). And "gee wiz" technology sells high end luxury cars.
Mazda just adapted those systems to the FD. The FD is a little more modern than the 13B-RE with a different crank angle sensor, better mounting, etc.
Mazda just adapted those systems to the FD. The FD is a little more modern than the 13B-RE with a different crank angle sensor, better mounting, etc.
01-22-10, 05:44 PM
#3
You're a bit too generalized mr OP.
significantly faster spool, very slightly less power.
versus, significantly slower spool, very slightly higher power.
If you are doing large track driving, then sequential is pretty pointless as you will rarely drop below the rpm threshold to revert back to primary turbo operation only... if you are autocrossing, sequential is great.
If you were selling a car that is going to be driven mainly on the street... which is what 90%+ of rx7s are driven on.... wouldn't you want it to lend itself perfectly to that environment? sequential operation makes for a VERY fun car to drive in town. even short burst of speed are easily achievable and you are not required to break the speed limit every time you hit boost. Though many people like to track these cars, Mazda still had to make something that would sell itself on a test drive.
significantly faster spool, very slightly less power.
versus, significantly slower spool, very slightly higher power.
If you are doing large track driving, then sequential is pretty pointless as you will rarely drop below the rpm threshold to revert back to primary turbo operation only... if you are autocrossing, sequential is great.
If you were selling a car that is going to be driven mainly on the street... which is what 90%+ of rx7s are driven on.... wouldn't you want it to lend itself perfectly to that environment? sequential operation makes for a VERY fun car to drive in town. even short burst of speed are easily achievable and you are not required to break the speed limit every time you hit boost. Though many people like to track these cars, Mazda still had to make something that would sell itself on a test drive.
01-22-10, 06:24 PM
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Maybe Mazda didnt forsee reliability issues. And when/if they did they realized it would be too expensive for a car in this price range to solve.
However you should read the thead here somewhere that posts quotes and so forth from mags that tested the car 93-95. They are very good reviews for the most part.
Had they gone non-seq, they may have surpassed peak power of the competition but the powerband would've been too narrow. IMO
In order to sell the car to more than just enthusiasts (who would've actually said "gee whiz") they needed to have some low-end torque of the seq system.
The competition (300zx, et al) had the torque and driveability of a v6, plus tt.
However you should read the thead here somewhere that posts quotes and so forth from mags that tested the car 93-95. They are very good reviews for the most part.
Had they gone non-seq, they may have surpassed peak power of the competition but the powerband would've been too narrow. IMO
In order to sell the car to more than just enthusiasts (who would've actually said "gee whiz") they needed to have some low-end torque of the seq system.
The competition (300zx, et al) had the torque and driveability of a v6, plus tt.
01-22-10, 08:08 PM
#5
Giving all the engineering hurdles, budgets, and reliability issues...it seems like a big waste of money and time.
Was it simply so they could say "we did it!"
Perhaps just a marketing scheme?
Far as I see it...
Seq = faster spool less power
Non seq = slower spool more power
Is the slightly faster spool really worth the hassle?
I'm really curious as to WHY Mazda choose to make the worlds first production sequential turbo setup?
Was it simply so they could say "we did it!"
Perhaps just a marketing scheme?
Far as I see it...
Seq = faster spool less power
Non seq = slower spool more power
Is the slightly faster spool really worth the hassle?
I'm really curious as to WHY Mazda choose to make the worlds first production sequential turbo setup?
You must don't know Mazda too well!
Mazda's focus (when it came to the rotary) was to always engineer the vehicle around the engine. Handling and response has always been Mazda's biggest theme. Hp was secondary. All the other manufacturers build their sports car the other way around. Now as far as the turbo system. It's simple! The Fd is still a street car. That means 99% of it's life will be on public roads. Stop and go traffic, low rpm cruising, ect. An engine with more torque is always more pleasurable to drive around. Two rotors don't have any. Since the Fd was to only be turbo charged, the sequential system was the best option in improving the bottom end for the smallish engine.
01-23-10, 09:24 AM
#6
Constant threat
You're a bit too generalized mr OP.
significantly faster spool, very slightly less power.
versus, significantly slower spool, very slightly higher power.
If you are doing large track driving, then sequential is pretty pointless as you will rarely drop below the rpm threshold to revert back to primary turbo operation only... if you are autocrossing, sequential is great.
If you were selling a car that is going to be driven mainly on the street... which is what 90%+ of rx7s are driven on.... wouldn't you want it to lend itself perfectly to that environment? sequential operation makes for a VERY fun car to drive in town. even short burst of speed are easily achievable and you are not required to break the speed limit every time you hit boost. Though many people like to track these cars, Mazda still had to make something that would sell itself on a test drive.
significantly faster spool, very slightly less power.
versus, significantly slower spool, very slightly higher power.
If you are doing large track driving, then sequential is pretty pointless as you will rarely drop below the rpm threshold to revert back to primary turbo operation only... if you are autocrossing, sequential is great.
If you were selling a car that is going to be driven mainly on the street... which is what 90%+ of rx7s are driven on.... wouldn't you want it to lend itself perfectly to that environment? sequential operation makes for a VERY fun car to drive in town. even short burst of speed are easily achievable and you are not required to break the speed limit every time you hit boost. Though many people like to track these cars, Mazda still had to make something that would sell itself on a test drive.
Quoted for truth.
There have been other manufacturers that have done sequential turbos, or having a supercharger for low-speed punch that gave way to a turbo charger at higher rpms. Turbo lag is THE #1 complaint amongst cars with turbocharged engines...so Mazda was very wise to develop the system they did.
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01-23-10, 12:40 PM
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rant! even if the FD came with some 400hp single turbo engine that ran 11's off the showroom floor, the magazines would have complained about the lack of torque under 3000rpms...
i actually got to drive an FD with a hybrid FC turbo on it, and its nice, it goes about like stock, but has a real boring power delivery. the twins are complicated and stupid, but they are FUN on the street. there is NOTHING else that delivers power like that
*in production, emissions legal warrantable trim.
01-23-10, 02:04 PM
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01-23-10, 10:16 PM
#15
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You also have to remember that during the era of the early RX7's the 'gentlemans agreement' was still around (look at most Japanese sports cars from around the early 90's, and all will be slightly less than 280/270HP). I doubt Mazda had any urge to build more power, much less change the whole turbo system just to gain 15 hp or so.
01-24-10, 10:01 AM
#16
I would have to disagree with the less power statement. A friend of mine that had his car built at defined autoworks made 360whp fully sequential. In fact my friend was adamant that the sequential system worked, and worked properly. I only made 334 non sequential on my car. I don't think many people decide to put the time and effort into there FD to really find out what works. Mazda had allot of time and research go into the FD. Mazda is also a very small company, and had money trouble at the time of the FD. I don't think mazda would have wasted there time or money if they did not feel the sequential system was much better. In my opinion a working sequential car gives a better feeling than a non sequential.
01-25-10, 03:44 PM
#17
And add first production hydrogen engine (rotary)
08-04-12, 09:50 PM
#19
With a few less flapper doors, and waste gates in the way, a non seq system could likely flow a tab bit more. the problem is you pick up lots of power when you port the waste gates and get good stable boost, something that is usually done when going non seq, but non done so many stock seq setups.
You guys are comparing 3 things here, not 2.
stock seq
modified non-seq
Modified Seq<- king for any rotary setup under ~450rwhp.
08-05-12, 04:52 PM
#22
Basically EVERYONE who has ever driven a rotary complains about lack of low end power, so Mazda was looking to resolve this issue.
FD sequential is still a dog from 1,000rpm to 2,000rpm.
Starter/generator/electric-supercharger with engine cut at stop is the answer for rotary for this and many other woes.
FD sequential is still a dog from 1,000rpm to 2,000rpm.
Starter/generator/electric-supercharger with engine cut at stop is the answer for rotary for this and many other woes.
08-08-12, 01:05 AM
#23
Add a couple cats to your non-seq FD and show the dyno graph.
Seq works great for the street. Nice singles make more power but the are 10-20yrs ahead of the development of the seq FD and would never have the response or power with cats to pass Federal emissions tests.
Now a bunch of V6 Mustangs, Altimas, etc are almost as fast in a straight line as a stock FD.
Seq works great for the street. Nice singles make more power but the are 10-20yrs ahead of the development of the seq FD and would never have the response or power with cats to pass Federal emissions tests.
Now a bunch of V6 Mustangs, Altimas, etc are almost as fast in a straight line as a stock FD.
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