Yeah, I read the thread. My point was that there are two issues here. One is whether components of the sequential system tend to break easily, the other is how difficult they are to diagnose/fix.

I doubt that components on the sequential system break any more easily than those of any other system, but I do think they can be difficult to diagnose.

Therefore the question of whether people "have problems" with the sequential system needs to be a little better defined (or just refined).

My personal opinion is that the sequential system is great. There's a bit of a learning curve when messing with it, but once you understand the basic concept it's not that hard to troubleshoot (can't beleive I actually said that).

 

Actually, nobody said it was easy to troubleshoot the sequential system. The conversation was about going to the poor-man's NS to fix a boost problem and whether that is a good idea or not.

However, that thread has a lot of information in it so hopefully people will take what they need from it.

 

Never any problems. Owned it now going on almost 10 years.

Tim

 

I converted to non sequential and never looked back

 

Exactly. NS is a good answer to fix boost issues, because diagnosing the seq. system is so tedious and difficult. And with NS, there are no boost issues (not "no boost issues", but not nearly as many control system related issues).


You hit the nail on the head my man. The non-seq system is not worth the trouble. As I stated in the other thread, (which is now being disputed) something WILL break. And I tried unsucessfully to find the solution to my problem. It just is not worth the trouble to go through fixing the thing when something fails. And the whole point of this poll is to see what percentage of third gen owners (only the ones on here, of course Mahjik) have had things fail.

To anyone willing to redo my sequential system, I'd be all for it. Because if it gave me 10 years of reliable service, or even 5, I'd be a happy man. But my point again is that it's too complex to be worth its benefits.


I see your point. But the point of the poll is to decide just how many have had issues. Thinking back, my original poll question should have been stated quite differently.

 

Hmmm, well if your end conclusion is switch to non-sequential, then I'm afraid I don't. I LIKE the sequential system when it works. When it doesn't...and that has happened more times than I'd like...I sometimes mutter things about non sequential conversions or single turbos, but in the end...I'd prefer to have the characteristics of properly working sequentials. For street driving, which is what I do, its just better, IMO.

jds

 

OK, I've got to stop replying to posts and then reading the rest afterwards. I guess you aren't in the anti-sequential crowd after all, my bad!

jds

 

Yes, but the poll really doesn't mean anything. Are you going to say that because people have had problems with 10 year old equipment, that it's bad? This poll is really about as useful as asking how many people have replaced their spark plugs or their tires..

If the car was 2-3 years old, it would make sense. However, as many other people have stated, it's mechanical nature to eventually have failures.

When it becomes problematic, it never works, then it's bad. i.e. you replace something and less than a year it's broke again (or some short span of time and keeps failing/breaking).

Like turbojeff, I've had years of problem free operation of the sequential turbo system. I know something will eventually fail, however at 7 years and running, I can't complain. When something does fail, I'm not going to throw my hands up and say "This POS. It only lasted 11 years. Longer than the original motor, door handles, and half the other stuff on my car that's already been replaced. That's it's, I'm getting rid of it!".

So what's the magic number for you to say that it's not a problem? If it runs without problems for 1 year, 2, 10, 50? Everyone has their limits as to when things become a problem for "them". That's what makes us all different.

 

never had a single problem.

 

I had quite a few problems. I never diagnosed it, becasuse of all BS in the rats nest. After doing all the bolt-ons minus a cat back, my car would never give me a constant boost pattern. Sometimes, I'd get a 11-8-14, sometimes a 9-7-0. One time I had a nice 11-10-17 run...it just never was quite right. One night i decided to go through the rats nest and fix everything. Even orderd a hose kit. Tore off the upper intake manifold, and just decided that I did'nt want to even deal with it. Next day I orderd a Power FC (was using a pettit unlimited.) and a block off plate kit, and have'nt looked backed. I'm not into auto X ing, mostly drag racing, so it was alot nicer for me. Would I go back? No. Would I switch to non-seq if the car was running right? No. My thoughts are if it ain't broke don't fix it. But if its a becoming a real pain, switch. CJ

 

Thats another point I'm attempting to make here. Many of those of us that have had seq issues have switched to non-seq. It's the ones that haven't had to deal with chasing boost leaks and crappy solenoids who swear by the seq system.

To those of you that haven't had an issue with the seq system I say this: Wait until your time comes. Maybe then you'll agree that it's too much of a PITA to make it worth the rewards.

Mahjik, My limit on re-doing the entire seq system would probably be somewhere in the 5 year range. And as you've been fault free for 7 years, I can understand why you swear by the seq system. Were I in your shoes, I'd probably do the same. But then again I'm not, so we'll never know will we?

 

Mahjik: It sounds like you agree that the sequential system has components that fail (just like any other system after 10 years), so that part is not really in question any more. Now, if it was easy to diagnose and replace those components then there would be very little to talk about here, but apparently its not. That's what drives people to go ns: not just because the sequential system breaks (as any system will), but because it can be a pita to fix.

I thought I had boost problems, and I did alot of learning and testing before I found out it was just my altitude. So I know what kind of effort it takes to fix the sequential system...and I still think its worth the effort.

My conclusion:
-The sequential system often breaks (not unusual)
-it's a pita the fix
-some people don't feel like putting forth the effort to fix it, so they go ns.
-Mazda could have avoided this problem if they designed a control system that either had a longer life or was simpler/easier to fix.

 

How about this.....if there is a thread that relates to this one it should be linked in the first post. Not everyone has time to read every post on the entire forum. Especially since there are 1000's of posts a day.

As for the seq question. I drove my car in stock seq for about 18 months running between 10-13psi of boost without one seq problem. Poped a engine due to XS pos tuning then when I put it all back together I used Rob's seq simplification method for ease of reinstall. From there I ran 13-15psi of boost for about a year with never a problem. Then when I installed BNR stage 3's I ran them non seq and still dont have any problems.

I should point out though that my car was/is in very good condition and has realitivly low miles.

STEPHEN

 

Why'd you go non-seq with the BNR's?

 

I had one problem with it three years ago. That problem caused me to learn how to replace vacum hoses
I like sequential well enough, but after my engine died last year I wanted to simplify things and went nosequential. It took me a bit to get used to the small amount of lag (mostly i just had to adjust my driving style) But i would never go back to the old cluttered/problematic/unstable boosting of the sequential system. I dying to get rid of these twins this winter anyway..

 

Thats what Brian (BNR) suggested and I agreed with him. The larger compressor wheels and diffference in spooling means your going to need to spend quite a lot of time "tuning" the boost pattern, especially around transition. If you notice, the only people that kept them seq and working good were the people that had them installed and "boost tuned" by Steve Kan or Dave. Everyone else has had a hard time getting the transition set up right.

Also, when you go full non seq you can make more power by removing the seq flap in the exh manifold.

In addition they were spooling so damn fast I didnt miss the seq. I was making just as much power at 3000 with non seq as I was with seq. Then at about 4000 my non seq set up pretty much left the seq in the dust. The only advantage seq had was under 3000 but around town when I'm just cruising I dont notice it and if I'm trying to drive spirited I dont run under 3000 anyway so its no biggie.

STEPHEN

 

Exactly.

Mahjik, before you jump all over me, I know that most of us non-seq guys don't have BNR's, but his point would remain the same. The only advantage seq has for me is under 4000 rpm, but if I trying to drive spirited, it only takes a second or two to get it over 4000 rpm.

 

Also, its decieving unless you compare dyno sheets between 2 cars with similar mods that have both been tuned good, one seq and one non seq. This is why...

You might not hit full boost till say 4000 in non seq BUT your running 2 turbos instead of one so you dont need as much pressure to make the same power. If a seq car hit 12psi at 3000 and a non seq car only hit 8-9psi at 3000 they are probably going to make about the same power due to the non seq car running 2x more turbo when under 4500rpms.

STEPHEN

 

Ok, but you've only had your car for 2 years. Even then, it was older than 5 years when you got it.

Seeing as it was a '93, you bought it in '01 and then started seeing problems... without knowing how the previous owner(s) treated the car it still sounds like the components held up fairly well.

I don't swear by the system. However, when someone asks about lag with the non-seq on the stock turbos, I tell them to just troubleshoot the sequential system. If you have to ask about lag, then you don't want it.

Granted, other turbo cars do have lag since they are mostly single turbo setups. The FD offers the ability to not have the lag so why not use it if you have stock twins?

Often breaks? That's not an accurate statement. That means as soon as you fix it, it's broke again. It may be a pain to troubleshoot, but most people usually don't have a problem again for quite some time once they get their problem sorted out.

Yep, that is true. However, I have seen dyno charts of similar cars (seq and non-seq on stock twins) and it's only around that 4000 mark where there is a slight edge for the non-seq setup. However, there is quite a bit lost in the low end and many people on the stock twins have noted that in other the thread.

Stephen, there are two debates going on in two separate directions which makes this thread confusing and useless. Once again, all I said was that going non-seq to fix a boost problem is not a good way to resolve a boost problem and also doesn't guarantee the problem will be fixed (as there are other issues that can cause boost problems not related to the sequential control system).

 

I never said it breaks repeatedly. My meaning could have been clarified by referring to my previous posts. When I said "often" I meant that it is not uncommon among FDs for components of the sequential system to break. I was simply agreeing with you.

 

Or they have an FD with < 20K miles

 

Actually, I've had it about 6 months. For the other year and a half it was my brothers, but I loved it more than him, so he sold it to me

I'm done debating this issue now. To each his (or her) own.

 

No problems in the 3+ years I've had the car

 

I agree that the thread is useless lol. Really though in terms of people dynoing similar cars the difference I normally see is that the seq car has a map with fuel and timing designed for the seq set up. The non seq car still has a map designed for the seq set up which means its not tuned properly in the lower rpms. This can cause huge differences in lag.

As for the debates, I wasnt really trying to get into the debate of which set up is better. I like them both for different reasons. I was mearly showing I never had any problems with my seq system, even with high boost....however it did have low miles. Then I was giving some input about the non seq after someone asked me some direct questions about it.

Also, in my case I've never driven a non seq car with stock twins. I have the Stage 3's and they seem to spool faster than the stockers. And before I get a million PM's, no I've dont have any problems with my BNR's lol

I tell ya what though, once you see the top of the engine and realize you could change injectors without ever removing the uim its all down hill from there HAHA

STEPHEN

 

No problem Stephen,

I wasn't trying to attack you. I was just trying to clear up what was going on. It all stemmed from a very bad phased statement which said something to the effect "there are many people who have not had problems with the sequential turbo system". I should have used the word "problematic" as that's really what I was attempting to convey.

Well, I do disagree that tuning will make a huge difference in the lag. Some difference I will agree upon but most of the people converting to non-seq are still using the stock ECU. Even the dyno's of the tuned guys still have that little bit lacking in the low-end. However, I don't think anybody's lowend compares to Artguy's.

As far as the injector thing? I hope to never need the convience of changing my injectors for that.