AntiVenom7

yea i am gonna have to back gfelber up on this. don't spread rumors and lies about single turbos my SP63 w/.96A/r (which i would consider medium/large) creates substantial boost (more than 10PSI) by 3500 and full boost(16PSI) by about 3900. It isn't even ball bearing.

From the RPM numbers that i am reading about the sequential setup I don't feel too bad at all.

jpandes

I see full-boost(1 bar = 14.5 PSI) at 3600-3800 rpm. My car was converted the Po' Man's way. Most people switch to NS due to nagging Seq. Turbo issues, like me.

I was just too lazy to try and trouble shoot the Seq. system. So, I went NS. Yeah the lag bugs me, since I drive mostly in the City(SF), On the other hand, my boost comes on smooth & linear and is RELIABLE and strong.

I was going to have the shop that did the R&R of my new ported motor convert my car back to Seq. But they couldn't guarantee that my Seq system was going to be perfect.

darkphantom

iTrader: (2)

When i got the car it came with the non sequential stuff. but whoever did it didnt do it right. it still had one of the solenoids connected. But when its done right. & you reach2-3K. WATCH OUT! cause you better be ready when the turbos wake up. Now i did had a chance to race against a seq vs non seq. and the off the line is ok. but for the HWY. non seq kicks ***.

Also theres a whole lot more room ( and access to other stuff) once you remove that rats nest. the turbos heat will be less contageous to everything else around also!

cewrx7r1

iTrader: (2)

This same comparison of seq to non-seq has raged for years,

It comes down to this;
(1) are you a gear banger who works the car to full potential, a real sports car person?

or

(2) are you more of an AUTO trans type of pseudo sports car person?

littlemilla3

iTrader: (1)

I was talking about something like a T88, which is what I consider large. GT35R's are small singles.

I agree that a GT35R is better than non-sequential stock twins in every aspect (except price).

Mahjik

iTrader: (1)

More like:

1. You want to lose 50-60 ft/lbs of torque by 3000 rpms on a car that already doesn't produce tons of torque...

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/non-sequential-turbo-questions-248396/page5/

ruos

iTrader: (1)

Right. Those are the ones who floor their cars from stop light to stop light, because their setups are worthless underneath 3500 rpms.

jimlab

Or...

2. You're too lazy to downshift when you want to accelerate quickly.

Mahjik

iTrader: (1)

Unless your in 1st.

Hmmm, you rarely see V8 people trying to lose low-end torque.

The problem is not shifting, it's more as to why make the car respond less? As most people switch to non-seq instead of fixing their seq boost problem, and that's just plain lazy. If people just want to lose 50 ft/lbs of torque before 3000 rpms for the heck of it, I could care less. However, the seq system doesn't mean lazy; it means using a complicated system designed to cost effectively defeat the lag of spooling up both turbos (or a single larger turbo).

For a lot of people, it's a good thing.

jimlab

You're kidding, right? Maximum torque multiplication is in first gear. I could see someone complaining about cruising in 3rd or 4th and wanting to just step down on the gas and go without downshifting, but 1st gear? That's ridiculous.

I did. I purposely built my 396 to kill low end torque with very short intake runners and fairly large intake ports because I knew I'd have trouble putting the power to the ground at low rpm. Of course, those same decisions promote high end power, so it's a good trade-off in a lightweight car like an FD.

I never felt like my car was unresponsive, nor did anyone shitting themselves in the passenger seat, that I could tell.

That's your opinion, and you're welcome to it, but please recognize that it is only an opinion, and not necessarily correct.

I've seen that opinion expressed many times over the last eight years, as if it were a badge of pride to keep the quirky and problematic sequential system, and the only people who would even consider switching are just lazy, too stupid to understand the sequential system, or were just dropped on their heads at birth. However, from my point of view, I have to wonder if the people bitching about non-sequential actually know how to drive.

FDNewbie

iTrader: (10)

I'm w/ Mahjik on this one. Oh and thanks for that great link. I didn't know about the diff in torque at all. Good stuff.

Oh and Jim, from my simple mind's understanding, the sequential system still seems to be the best of both worlds. More low end torque, quicker response, and it still behaves pretty much identical to a non-sequential setup, as long as you stay above 3K rpm. I think Rynberg's post in the other thread (that Mahjik linked to) sums it up the best:

So Jim, I don't understand how it's better to go non-sequential, assuming your sequential system works fine, and you can fix it when it does give you issues. Again, whether you downshift or not, as long as it's not under 3K, you're non-sequential...

jimlab

I've said it many times before, and I'll say it again... if your sequential system is working properly, leave it alone.

Maybe I had a magic combation (no, I don't believe that, since others have had the same results), but my car was working perfectly when I converted (as you'd expect, with only ~3,500 miles on the odometer), and I never once wished I hadn't converted it. If I bought another (assuming I were that stupid), I'd more than likely convert it too.

Maybe if I'd had full mods with the sequential system first and then converted, that might have made a difference. Maybe not. If I were an autocrosser, I might feel differently, but I'm not. Since I consider all rotary engines to be anemic where torque is concerned, to me it's a moot point that you're losing a bit of torque at low rpm when you've got a 2,800 lb. car with a 14.xx final drive in first gear and 8,000 rpm to play with. A downshift is all it takes to get the car moving quickly in any gear.

Which makes a lot of the arguments against non-sequential a little silly, don't you think?

FDNewbie

iTrader: (10)

I agree w/ you there.

Combation? You're slipping Jim...

My God...you have a very deep hatred for the FD, don't you? :shaking head:

Yes, but you know what Jim? I was just talkin to my friend about this (while he was riding shotgun). He was curious why I rarely drop it. I told him that w/ the sequential system, I rarely need to. But def, if you're getting on it seriously, you gotta drop it plain and simple, again, in which case you'd be in non-seq. mode. I just like not having to do so 90% of the time

Nope...because I don't argue the sequential system is great for getting on it heavy during road racing...I think it comes very handy when coming off the line, or any other situation where you're starting from low rpm. It's great to have it, and still run non-seq. at highway speeds when dropping it. Best of both worlds, vs. converting, and losing one function permanently.

BTW...did you switch to non-seq. cuz your sequential system was acting up (at 3500 miles! ) or didja do it for a write-up/experimentation?

Neakor

just jump to the conclution~
difference between Non and Seq.

------------------------------Seq-------Non----------------
1.Low end torque---------O----------X------------------
2.reliability(smooth)-------X----------O-----------------
3.Max power--------------equal------equal-------------
4.Construction------------simple------complicated----

rynberg

Hmmm....the non-seq guys always bring up the downshift thing, and the drive it like it's a sports car thing. For some reason, I guess throttle response, when you are just driving the car around, is not important.

Yes, if I want to really accelerate fast, I'll downshift. Duh! And I certainly know how to drive it "like a sports car". But I hardly want to keep downshifting when I'm cruising at 70-80 on the freeway and all I want to do is modulate my speed to get around people. I know from personal experience that such a simple activity in non-seq requires a downshift to 4th. Or cruise around town at 3500 rpm. When in non-seq, there is simply extremely poor throttle response below 3500 rpm. Now, Jim, I know that I still have a stock cat, etc., but I also know of several people who went non-seq and either went back, or really do miss the seq system. Most of these people are experienced FD owners who have owned their cars for years and had/have them set up FULL non-sequential.

No Jim, given my statements in the bit that Ramy (FDNewbie) copied, it makes the arguments against sequential operation a little silly.

I get the best of both worlds -- the responsiveness of sequential for daily street driving, and the predictable and smooth powerband of non-seq when I am tracking the car or hitting the back roads hard. The only REAL reason to go non-sequential is reliability/consistency of boost IMO. In hard driving, the less smooth powerband of seq isn't an issue after the first shift above 4500 rpm, either for drag racing or road racing. In fact, I've only been caught out once by the seq system in a corner, resulting in a nice 90 degree slide -- and that was at an auto-x when I was going through the last corner with a bad entry angle. The situation of having the seq spike at transition kick out your rear end in a corner rarely occurs except when the driver has made a mistake or is doing something stupid.

As far as reliability, as I recall, I've only had two boost issues with my car that involved the seq system in 3-1/2 years of driving (30k miles). And those were both due to age/heat related failures of my 85k mile all original check valves and lines. I expect to have perfect seq reliability for years after my car is all back together with all new parts, although that's probably a bit optimistic...

jimlab

Not my computer... keyboard is too small.

No, I'm just practical and I know too much about the car (and Mazda) to make the same mistake twice.

See my comments about 1st gear. Non-sequential has no problem whatsoever coming off the line. 1st gear lasts all of 2-3 seconds with full mods.

Like I said, downshift and there's no "penalty" from lag. In fact, you'd probably get the jump on a non-sequential car that just stepped down in the current gear thanks to gear multiplication, depending on the starting speed.

Which part of "working perfectly" didn't you understand?

jimlab

Maybe we don't mention it because we never had a perceived problem with throttle response. However, based on your comment below about still having your cat, I can understand why you'd have that perception.

Well, from some of the statements made about non-sequential, you have to wonder about the intelligence of the poster.

The people whining about lack of torque sound like they thought they had big blocks to begin with. There is a decrease in torque at low rpm, but how long do you actually stay below 3,000 rpm when accelerating in the appropriate gear? It's a hollow argument, and the only reasons I can think of why someone would make it is because A) they're looking for any excuse to prove non-sequential is "bad", or B) they're just too lazy (or ignorant) to downshift.

Not true at all. I suspect you were driving a car that wasn't properly/fully converted.

See above. Not in any of the non-sequential cars I've ridden in or driven.

That explains a lot...

If they went back easily, they weren't "FULL" non-sequential.

Who's making arguments against sequential? You don't have to be against sequential to speak the truth about non-sequential.

Mahjik

iTrader: (1)

Well, yes I was kidding about 1st gear. However, just like any car, you drive it the way it's can be driven. If you are in a car that has no power down low, you keep the revs high by shifting. Changing to non-seq changes the characteristics of the stock turbos output thus requiring a different driving style than what was intend by the original design of the car. Nobody is argueing that, but saying people don't know how to drive because they like the sequential system offering them power in lower rpms is basically ridiculous.

I guess those people never rode in a car with a perfectly functioning sequential system putting out about the same power to compare.

Jim, that goes both ways. I never stated it as fact, however I can dig up all the threads of people converting over to non-seq because of problems on the seq side that they did not want to troubleshoot. There are far more of those than the people who did it willingly.

Once again, you didn't read the statement. I'll post the words it started with: most people...

That didn't read all people, just most. Yes, the sequential system becomes problematic when trying to go for high HP numbers in the 400+ or so range. Those are the people who usually switch to non-seq without having serious problems with the sequential system.

I could care less who runs non-seq or who doesn't. The reasons *why* people choose one or the other doesn't really matter as it's subjective to each individual. What we do have are dyno's showing the seq gain of torque in the lower rpms over the non-seq without much difference (if any) in the top end.

rynberg

True, they weren't "fully" converted as you describe it, so you've got me there. However, there is also no denying that a sequential car has 50-60 more lb-ft to the wheels at, what I consider, everyday driving around speeds of 2600-3300 rpm, even when fully converted. The feel of instant boost/torque in that rpm range makes the car fun to drive without "getting on it".

No, they ended up having to buy all new (or lightly used) OEM turbos.

Sorry about that, I lumped you into the group of people who DO argue against sequential.

As far as this never-ending debate goes, you can notice trends in drivers' views -- those who use their car on a regular basis or daily drive it tend to prefer sequential, and those who don't, don't. I know that if I only drove the car to go out and beat on it or go to the track, I would convert to non-sequential too for better reliability. If I didn't live in a smog-**** state, I would ditch the twins altogether for a small single turbo.

1QWIK7

iTrader: (33)

you think you cant stand waiting for 3k-3.5k for boost, try waiting until 4.5k

turbojeff

iTrader: (30)

I wonder if non-seq guys downshift to 1st gear everytime they round a corner in town?

When I'm just driving around town I go around most city corners in 2nd gear, rpms are probably in the 2500-3000rpm range, I like to have a little bit of acceleration coming out of those types of corners. I don't think it is a matter of being "lazy" I think it is a typical driving situation.

Neakor

i dont want to get nothing for 3.5k rpms but 1k rpm with only a half acceleration is acceptable.

jimlab

Once again, I'm not saying this because they like the sequential system. I'm saying it because they apparently don't know how to drive a non-sequential car.

I'm sure there are, but to make a general statement that people only switch to non-sequential because they can't/don't want to troubleshoot the sequential control system is wrong. I think you come off sounding far more biased against non-sequential than you realize. Or perhaps you do realize...

Then why make it sound like non-sequential makes the car completely undriveable? You have to know that's completely false.

jimlab

No.

Nameless

I switched willingly - from a perfect 10-8-10 pattern - and have loved it for the past couple of years.