Going non-seq, need advice?
#26
Iv driven my car with both setups, although I didn't really do the full conversion, I just pulled vac lines.
I have full exhaust, extremely ported W/G <<<<which is what you will need to have any advantage over sequential. If you dont have a full exhaust you can completely forget any power gains....the lag is unbearable...and on top of that if you DO put on a full exhaust you MUST port the crap out of your wastegate. I ended up having to port the center housing so that the flapper could actually move further.
I will admit, non-seq feel better if you are trying to do highway pulls, but around town driving is NOTICEABLY less pleasureable.
Right now, when I travel up a slight incline, I can feel the backpressure of my primary against the throttle body plates...the turbo is just ready to spool even at 2.2krpms in 2nd gear at 30mph. I get instant torque to pull me up a hill without having to downshift/be loud. I non-sequential mode...the boost gauge just doesn't move until your really ask for boost. You can't spool/snap your BOV at all. Theres no 4psi in neutral from revving the engine. Its just boring.![Dunno](https://www.rx7club.com/images/smilies/dunno.gif)
I mean, bottom line is, rotary has no low-end torque. You have to rev up the engine to get power. BUT, if you have a sequential setup, it makes up for that low end driveability.
I have full exhaust, extremely ported W/G <<<<which is what you will need to have any advantage over sequential. If you dont have a full exhaust you can completely forget any power gains....the lag is unbearable...and on top of that if you DO put on a full exhaust you MUST port the crap out of your wastegate. I ended up having to port the center housing so that the flapper could actually move further.
I will admit, non-seq feel better if you are trying to do highway pulls, but around town driving is NOTICEABLY less pleasureable.
Right now, when I travel up a slight incline, I can feel the backpressure of my primary against the throttle body plates...the turbo is just ready to spool even at 2.2krpms in 2nd gear at 30mph. I get instant torque to pull me up a hill without having to downshift/be loud. I non-sequential mode...the boost gauge just doesn't move until your really ask for boost. You can't spool/snap your BOV at all. Theres no 4psi in neutral from revving the engine. Its just boring.
![Dunno](https://www.rx7club.com/images/smilies/dunno.gif)
I mean, bottom line is, rotary has no low-end torque. You have to rev up the engine to get power. BUT, if you have a sequential setup, it makes up for that low end driveability.
#28
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What's wrong with that? It's got a 8k redline for a reason. Go ahead and use the whole rev range.
#32
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Different people have different goals so it certainly is a matter of preference, but I just hate it when people dump on a non-seq thread with the standard "OMG lag!" "people only do that when they're too dumb to fix their seq system!" responses. It gets my blood pressure up.
Pros: simplicity, less to break, smooth power delivery, no more boost spikes
Cons: increased lag (this is mitigated by full exhaust, which requires wastegate porting to avoid boost creep)
Notice I didn't put more power in the pro category. Non-seq gives up some of the low range power for a little more mid range, but you're not going to see huge gains overall. So unless you're trying to squeak the last couple of horsepower out of your car, I don't think non-seq is worth it for extra horsepower. The biggest selling point for me is the simplicity. Maintenance is a breeze when you're non-seq.
Pros: simplicity, less to break, smooth power delivery, no more boost spikes
Cons: increased lag (this is mitigated by full exhaust, which requires wastegate porting to avoid boost creep)
Notice I didn't put more power in the pro category. Non-seq gives up some of the low range power for a little more mid range, but you're not going to see huge gains overall. So unless you're trying to squeak the last couple of horsepower out of your car, I don't think non-seq is worth it for extra horsepower. The biggest selling point for me is the simplicity. Maintenance is a breeze when you're non-seq.
#34
For all of those saying "just do a full exhaust and blah blah blah to make up for the lag difference. Here are a couple thoughts for you:
non-sequential + full exhaust = MUCH louder and still quite expensive.
full sequential + full exhaust = MUCH louder and still quite expensive... with even BETTER spool.
Even for even, full sequential is the only way to run the stock twins. Otherwise, it is just like running an inefficient single. And you can still run a single at lower boost on the stock ecu. Just like you can run non sequential. And single turbos are getting relatively inexpensive... compared to a full ti exhaust system for example.
non-sequential + full exhaust = MUCH louder and still quite expensive.
full sequential + full exhaust = MUCH louder and still quite expensive... with even BETTER spool.
Even for even, full sequential is the only way to run the stock twins. Otherwise, it is just like running an inefficient single. And you can still run a single at lower boost on the stock ecu. Just like you can run non sequential. And single turbos are getting relatively inexpensive... compared to a full ti exhaust system for example.
#35
For all of those saying "just do a full exhaust and blah blah blah to make up for the lag difference. Here are a couple thoughts for you:
non-sequential + full exhaust = MUCH louder and still quite expensive.
full sequential + full exhaust = MUCH louder and still quite expensive... with even BETTER spool.
Even for even, full sequential is the only way to run the stock twins. Otherwise, it is just like running an inefficient single. And you can still run a single at lower boost on the stock ecu. Just like you can run non sequential. And single turbos are getting relatively inexpensive... compared to a full ti exhaust system for example.
non-sequential + full exhaust = MUCH louder and still quite expensive.
full sequential + full exhaust = MUCH louder and still quite expensive... with even BETTER spool.
Even for even, full sequential is the only way to run the stock twins. Otherwise, it is just like running an inefficient single. And you can still run a single at lower boost on the stock ecu. Just like you can run non sequential. And single turbos are getting relatively inexpensive... compared to a full ti exhaust system for example.
My sequential system runs amazing and I love the kick at 4500rpms....you can practically conduct it with your hands. Just a clean pull up to 4500 and then boom...you are slammed back in your seat. Also, the primary sounds AMAZING through an open exhaust. You CANNOT get this sound at low rpms with non-seq...instead it sounds hollow like an RX8. If you do have seq. setup and your rev past 4500rpms but don't let the rpms drop past 3K the car stick in non-seq and you get a crappy exhaust tone. You cannot get this sexy low end sound on any single either.
My spool is absolutely insane....I've NEVER been in any turbo car that will snap from 0psi to 10psi in a split second below 3k rpms. However, if I was aiming for more than 15psi....I would SURELY convert to non-sequential in a heart beat. Its too hard to control high boost on seq.
#38
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For all of those saying "just do a full exhaust and blah blah blah to make up for the lag difference. Here are a couple thoughts for you:
non-sequential + full exhaust = MUCH louder and still quite expensive.
full sequential + full exhaust = MUCH louder and still quite expensive... with even BETTER spool.
Even for even, full sequential is the only way to run the stock twins. Otherwise, it is just like running an inefficient single. And you can still run a single at lower boost on the stock ecu. Just like you can run non sequential. And single turbos are getting relatively inexpensive... compared to a full ti exhaust system for example.
non-sequential + full exhaust = MUCH louder and still quite expensive.
full sequential + full exhaust = MUCH louder and still quite expensive... with even BETTER spool.
Even for even, full sequential is the only way to run the stock twins. Otherwise, it is just like running an inefficient single. And you can still run a single at lower boost on the stock ecu. Just like you can run non sequential. And single turbos are getting relatively inexpensive... compared to a full ti exhaust system for example.
No one disagrees with you, but obviously, money is a big issue for most people. Like previously mentioned, if it wasnt, everyone would be running a single turbo.
#40
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We can argue the spool question all day, it comes down to personal preference. I prefer increased mid-range and a smooth power band while others may prefer an increased low range with the secondary transition. What you can't argue is the ease of maintenance on a non-seq car.
#41
the only advantage to non-seq is running higher than 15psi without having actuator problems.
If you are running below 15psi, non-sequential is retarded in my opinion....unless you have non-funtial sequential system and don't want to spend alot to fix it. But, if you have functional sequential system, leave it alone. Get a greddy profec B spec II run it on your sequential sytem. Sequential is the whole point of the twin setup otherwise mazda would have made a single. And no, switching to non-seq is NOT like a single turbo....its like an inefficient single with lots of heat, so get your money's worth out of your car by at least utilizing the expensive sequential system that it was designed for.
I made 328rwhp at 15.5psi on stock turbos/stock ports/sequential. You might make 10-15hp more on non-sequential, but the car lags like hell.
If you are running below 15psi, non-sequential is retarded in my opinion....unless you have non-funtial sequential system and don't want to spend alot to fix it. But, if you have functional sequential system, leave it alone. Get a greddy profec B spec II run it on your sequential sytem. Sequential is the whole point of the twin setup otherwise mazda would have made a single. And no, switching to non-seq is NOT like a single turbo....its like an inefficient single with lots of heat, so get your money's worth out of your car by at least utilizing the expensive sequential system that it was designed for.
I made 328rwhp at 15.5psi on stock turbos/stock ports/sequential. You might make 10-15hp more on non-sequential, but the car lags like hell.
Even with my new Efini turbos and new Supra TT fuel pump, his non-seq with fouled plugs got 30 more hp than my seq setup.
On top of having more power, the car is more fun to drive. Power delivery is smoother, and you can say goodbye forever to the stupid transition. The pulling, then losing boost for 500 rpm, then getting it back gets irritating and makes your passengers (girls!) think you don't know how to drive smoothly or wonder what's wrong with your car.
People like to exaggerate the "lag" based on heresay or just guessing should probably drive a non-seq FD first before posting in this area. Or if you can't find a non-seq to drive, take off the UIM and have a have a look at what's underneath. Good luck trying to convince anyone that's a good design.
At the end of the day, it's your car, so do with it what you please. But if you've never driven both setups, perhaps you should refrain from posting here. For those with questions, this thread - and the others - should provide with real world feedback from people who have driven both setups.
#42
less maintence sounds nice.... but it also sounds like if you replace the vac hoses with the silicon ones that eliminates some of the problem. i figure ill keep the seq set up when i get my car and if im feelin froggy ill check out the non seq out and see how i like it.
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less maintence sounds nice.... but it also sounds like if you replace the vac hoses with the silicon ones that eliminates some of the problem. i figure ill keep the seq set up when i get my car and if im feelin froggy ill check out the non seq out and see how i like it.
![Lol](https://www.rx7club.com/images/smilies/lol.gif)
#44
Yeah thats what i thought, then my selinods started taking ***** on me left and right. Havent driven a seq yet but, i will once im done with my rebuild. I always hated that stupid 10 8 10 anyway. It just gets worse when you try to add more boost. I had all sorts of crazy boost transitions with all the correct hoses, and got fed up and said **** it. "Insufficient" single here we go....![Lol](https://www.rx7club.com/images/smilies/lol.gif)
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