parallel vs. sequential
Rotary Enthusiast
Joined: Jul 2003
Posts: 823
Likes: 0
From: Toronto
What is the simplified sequential?
Does it require alot of mods and time to do this?
Is there any guides I can read to do this on my own, provided I have the right tools and time on my hands.?
Does it require alot of mods and time to do this?
Is there any guides I can read to do this on my own, provided I have the right tools and time on my hands.?
this is my take. I converted from sequential to FULL non sequential to see what the big deal was about. I had a perfectly working sequential system but I was looking for reliability.
Sequential truths that I experienced:
Instant boost at anything above 2.9K rpms. Can be very tempermental. About every 6 months (I drive my car a lot) I would have some kind of boost issue which really sucks. I did a full vacuum hose job at it kept my system trouble free for about 3 years but then the problems began again. At elevated boost levels (above 12 psi) I would get a spike at transition (no harmn done but it bugged the **** out of me).
non sequential truths:
I didn't get 10 psi until I hit 3800 RPMs and supposedly I had all the right mods (SMIC, DP, MP, CB, Streetport). Some people claim they hit full boost at 2.9K here on the forum but I have not met one single person that has been able to do it, and I live in So Cal so there are a lot of FD's runing around. The system also had lag as it wasn't instant boost past 3.8 K RPMs. On the plus side I never had any more boost problems after I went non-sequential
A miscontrued truth about nonsequential: Increase the parallel power band by 700 RPMs and thus make your car faster. (remember 4500 RPMS @ sequential Vs 3800 RPMS non-sequential). True you do increase your power band but you certainly are not faster unless you brake boost... IMO that's kinda gay if you using the same turbos. Another thing to note that those 700 RPMs are only usable during your initial WOT. Most people shift at redline, which brings back your RPMs to above 4500 RPMs WHERE either setup ALREADY HAS BOTH TURBOS RUNING IN PARALLEL ANYWAY! so those extra 700 RPMs are not being used after the initial shift.
My buddy has porsche boxter before I went non-sequential I dusted his *** in every gear at 10 psi. After I went non-sequential and upped the boost to 12 psi I always had to play catch up. Why? the damn lag that's why. By the time I hit boost he was already ahead of me. Don't get me wrong I would dust his *** but like I said I would have play catch up first.
IMO the best of both both worlds is simplified sequential. Only 20 hoses instead of 72 for full sequential, or 6 for full non-sequential. So you keep the responsive factor and yet eliminate the majority of the hoses so it keeps things simple.
Sequential truths that I experienced:
Instant boost at anything above 2.9K rpms. Can be very tempermental. About every 6 months (I drive my car a lot) I would have some kind of boost issue which really sucks. I did a full vacuum hose job at it kept my system trouble free for about 3 years but then the problems began again. At elevated boost levels (above 12 psi) I would get a spike at transition (no harmn done but it bugged the **** out of me).
non sequential truths:
I didn't get 10 psi until I hit 3800 RPMs and supposedly I had all the right mods (SMIC, DP, MP, CB, Streetport). Some people claim they hit full boost at 2.9K here on the forum but I have not met one single person that has been able to do it, and I live in So Cal so there are a lot of FD's runing around. The system also had lag as it wasn't instant boost past 3.8 K RPMs. On the plus side I never had any more boost problems after I went non-sequential
A miscontrued truth about nonsequential: Increase the parallel power band by 700 RPMs and thus make your car faster. (remember 4500 RPMS @ sequential Vs 3800 RPMS non-sequential). True you do increase your power band but you certainly are not faster unless you brake boost... IMO that's kinda gay if you using the same turbos. Another thing to note that those 700 RPMs are only usable during your initial WOT. Most people shift at redline, which brings back your RPMs to above 4500 RPMs WHERE either setup ALREADY HAS BOTH TURBOS RUNING IN PARALLEL ANYWAY! so those extra 700 RPMs are not being used after the initial shift.
My buddy has porsche boxter before I went non-sequential I dusted his *** in every gear at 10 psi. After I went non-sequential and upped the boost to 12 psi I always had to play catch up. Why? the damn lag that's why. By the time I hit boost he was already ahead of me. Don't get me wrong I would dust his *** but like I said I would have play catch up first.
IMO the best of both both worlds is simplified sequential. Only 20 hoses instead of 72 for full sequential, or 6 for full non-sequential. So you keep the responsive factor and yet eliminate the majority of the hoses so it keeps things simple.
A miscontrued truth about nonsequential: Increase the parallel power band by 700 RPMs and thus make your car faster. (remember 4500 RPMS @ sequential Vs 3800 RPMS non-sequential). True you do increase your power band but you certainly are not faster unless you brake boost... IMO that's kinda gay if you using the same turbos. Another thing to note that those 700 RPMs are only usable during your initial WOT. Most people shift at redline, which brings back your RPMs to above 4500 RPMs WHERE either setup ALREADY HAS BOTH TURBOS RUNING IN PARALLEL ANYWAY! so those extra 700 RPMs are not being used after the initial shift.
just thought Id let you know. 
Chris
94 Single Turbo FD
Joined: May 2006
Posts: 1,418
Likes: 1
From: Calgary, Alberta, Canada
sequential system is the way to go when running the twins.
non sequential is for the people who cant keep there sequential system running and dont want to take the next step to a single
to run non sequential or a single u must have full exhaust,intake and a large streetport, then there is virtually no lag.
non sequential is for the people who cant keep there sequential system running and dont want to take the next step to a single
to run non sequential or a single u must have full exhaust,intake and a large streetport, then there is virtually no lag.
I love the sequential system, and wouldn't change it for the world (though I have everything in place already if I ever felt like going single).
This should answer your question...
Last edited by slayerx7; Apr 19, 2008 at 06:33 PM. Reason: pic didnt upload
-----MYOLD7UPYOURS-------
Joined: Nov 2006
Posts: 95
Likes: 0
From: wausau,wi
I dont mean to butt in on your thread?? I wish I knew what the seq setup felt like and how the 4500rpm transition felt like also, but I am in the middle of my full non-seq mod and I cant seem to find the write up for the 13bre engine? I only find it for the rew. I know they are close but different. Can anyone help me out?Thanks
In reality there isn't much to gain except only upon an initial WOT throttle run when you are below 4K. Just as non-seq when you shift at redline that extra powerband becomes useless. Don't get me wrong it's a nice mod to have since it makes the car faster even if it's for one gear.
Dave
thewird
The advantage is that it removes a small amount of redundant vacuum lines (it also removes all the emissions components). The downside is that you "really" need to understand the sequential setup to understand the pressure and vacuum paths of the sequential system. This is definitely required to understand the new routing as well as be able to troubleshoot it later on should problems arise. 90% if of the troubleshooting guides and general help you will receive from others will be based on the stock vacuum/pressure lines routing.
IMO, the simplified diagram is not a good option.
The advantage is that it removes a small amount of redundant vacuum lines (it also removes all the emissions components). The downside is that you "really" need to understand the sequential setup to understand the pressure and vacuum paths of the sequential system. This is definitely required to understand the new routing as well as be able to troubleshoot it later on should problems arise. 90% if of the troubleshooting guides and general help you will receive from others will be based on the stock vacuum/pressure lines routing.
The advantage is that it removes a small amount of redundant vacuum lines (it also removes all the emissions components). The downside is that you "really" need to understand the sequential setup to understand the pressure and vacuum paths of the sequential system. This is definitely required to understand the new routing as well as be able to troubleshoot it later on should problems arise. 90% if of the troubleshooting guides and general help you will receive from others will be based on the stock vacuum/pressure lines routing.
thewird
I dont mean to butt in on your thread?? I wish I knew what the seq setup felt like and how the 4500rpm transition felt like also, but I am in the middle of my full non-seq mod and I cant seem to find the write up for the 13bre engine? I only find it for the rew. I know they are close but different. Can anyone help me out?Thanks
i'm currently "rich man's non-seq" with a street-ported motor. i also ported the turbo exhaust side housings & wastegate. i don't notice any lag compared to seq.
i don't have a picture of the final porting, but here is a "work in progress" shot when i was porting the exhaust side of my non-seq conversion
Last edited by theorie; Apr 21, 2008 at 05:19 PM.
IMO, the simplified diagram is not a good option.
The advantage is that it removes a small amount of redundant vacuum lines (it also removes all the emissions components). The downside is that you "really" need to understand the sequential setup to understand the pressure and vacuum paths of the sequential system. This is definitely required to understand the new routing as well as be able to troubleshoot it later on should problems arise. 90% if of the troubleshooting guides and general help you will receive from others will be based on the stock vacuum/pressure lines routing.
The advantage is that it removes a small amount of redundant vacuum lines (it also removes all the emissions components). The downside is that you "really" need to understand the sequential setup to understand the pressure and vacuum paths of the sequential system. This is definitely required to understand the new routing as well as be able to troubleshoot it later on should problems arise. 90% if of the troubleshooting guides and general help you will receive from others will be based on the stock vacuum/pressure lines routing.
I've never ridden in a sequential equipped car. I've studied a lot of their dyno graphs. It cracks me up, whenever I show a sequential car's dyno to my V8 friend... they're like "whoa" That transition in torque @ 4.5KRPM is pretty weird to most people. BUT: there's something to be said for the extra torque before the standard transition point. If you're on the street with your car alot, I think it would be a lot better to have the extra torque that comes with a proper sequential turbo car--just for the fun factor.
My car is full non sequential and I have 3" exhaust (high flow cat), open intake, set my boost controller to open the wastegate around 7 psi, and I get full boost about 4,000 RPM (13 psi). I can make 10#s a little bit sooner (depends on ambient air temp), probably 3,800 RPM. Before that, the car is pretty much running N/A. And yes, it's slow. Once boost hits, I'm gone, but before that... it's like driving an N/A rotary car and that's no fun.
I'll post up some videos when I get a chance (I just got a new camera mount for my car) to show you how a non-seq car behaves on the street and track (I'm going to the drag strip this Sat. and a road course event next May).
One last thing: don't forget, the term "lag" means how long it takes (seconds) to get a specified amount of boost after you've hit the go pedal. "boost threshold" is the term that describes @ what RPM you get a specified full boost. So below 4,000 RPM, lag is bad with non-seq turbos. My boost threshold for 10 psi is about 3,800 RPM, while it's 4,000 RPM for 13 psi. Lag is not an issue above 4,000 RPM.
But you know what, my car is still fun as hell. I love it
That transition in torque @ 4.5KRPM is pretty weird to most people. BUT: there's something to be said for the extra torque before the standard transition point. If you're on the street with your car alot, I think it would be a lot better to have the extra torque that comes with a proper sequential turbo car--just for the fun factor.My car is full non sequential and I have 3" exhaust (high flow cat), open intake, set my boost controller to open the wastegate around 7 psi, and I get full boost about 4,000 RPM (13 psi). I can make 10#s a little bit sooner (depends on ambient air temp), probably 3,800 RPM. Before that, the car is pretty much running N/A. And yes, it's slow. Once boost hits, I'm gone, but before that... it's like driving an N/A rotary car and that's no fun.
I'll post up some videos when I get a chance (I just got a new camera mount for my car) to show you how a non-seq car behaves on the street and track (I'm going to the drag strip this Sat. and a road course event next May).
One last thing: don't forget, the term "lag" means how long it takes (seconds) to get a specified amount of boost after you've hit the go pedal. "boost threshold" is the term that describes @ what RPM you get a specified full boost. So below 4,000 RPM, lag is bad with non-seq turbos. My boost threshold for 10 psi is about 3,800 RPM, while it's 4,000 RPM for 13 psi. Lag is not an issue above 4,000 RPM.
But you know what, my car is still fun as hell. I love it
I've never ridden in a sequential equipped car. I've studied a lot of their dyno graphs. It cracks me up, whenever I show a sequential car's dyno to my V8 friend... they're like "whoa" That transition in torque @ 4.5KRPM is pretty weird to most people. BUT: there's something to be said for the extra torque before the standard transition point. If you're on the street with your car alot, I think it would be a lot better to have the extra torque that comes with a proper sequential turbo car--just for the fun factor.
My car is full non sequential and I have 3" exhaust (high flow cat), open intake, set my boost controller to open the wastegate around 7 psi, and I get full boost about 4,000 RPM (13 psi). I can make 10#s a little bit sooner (depends on ambient air temp), probably 3,800 RPM. Before that, the car is pretty much running N/A. And yes, it's slow. Once boost hits, I'm gone, but before that... it's like driving an N/A rotary car and that's no fun.
I'll post up some videos when I get a chance (I just got a new camera mount for my car) to show you how a non-seq car behaves on the street and track (I'm going to the drag strip this Sat. and a road course event next May).
One last thing: don't forget, the term "lag" means how long it takes (seconds) to get a specified amount of boost after you've hit the go pedal. "boost threshold" is the term that describes @ what RPM you get a specified full boost. So below 4,000 RPM, lag is bad with non-seq turbos. My boost threshold for 10 psi is about 3,800 RPM, while it's 4,000 RPM for 13 psi. Lag is not an issue above 4,000 RPM.
But you know what, my car is still fun as hell. I love it
That transition in torque @ 4.5KRPM is pretty weird to most people. BUT: there's something to be said for the extra torque before the standard transition point. If you're on the street with your car alot, I think it would be a lot better to have the extra torque that comes with a proper sequential turbo car--just for the fun factor.My car is full non sequential and I have 3" exhaust (high flow cat), open intake, set my boost controller to open the wastegate around 7 psi, and I get full boost about 4,000 RPM (13 psi). I can make 10#s a little bit sooner (depends on ambient air temp), probably 3,800 RPM. Before that, the car is pretty much running N/A. And yes, it's slow. Once boost hits, I'm gone, but before that... it's like driving an N/A rotary car and that's no fun.
I'll post up some videos when I get a chance (I just got a new camera mount for my car) to show you how a non-seq car behaves on the street and track (I'm going to the drag strip this Sat. and a road course event next May).
One last thing: don't forget, the term "lag" means how long it takes (seconds) to get a specified amount of boost after you've hit the go pedal. "boost threshold" is the term that describes @ what RPM you get a specified full boost. So below 4,000 RPM, lag is bad with non-seq turbos. My boost threshold for 10 psi is about 3,800 RPM, while it's 4,000 RPM for 13 psi. Lag is not an issue above 4,000 RPM.
But you know what, my car is still fun as hell. I love it
the more simple the system the more reliable it's going to be.
the stock seq setup is pretty complex and leaves more room for parts to break, especially on 12-15 year old cars.
if you convert them properly you won't even notice the difference in spool time, and its nice not having to worry about the 4500rpm transition.
I think the best thing you can do is learn a thourough understanding of the sequential system in complete stock form. Then from there the simplified system (and everything else for that matter) will be easier to understand/make more sense. This is the path Im on right now.
Personally, I beleive that for my purposes simplified is the only way to go because you shed the "fat" of the emmisions which I dont have to worry about anyway. If you need to keep emissions, and dont want to get completely engulfed in the system, then I would probally reccommend keeping it stock. As stated (I think) before its much easier to repair something stock, trace a diagram per manual, in the event of something horrible.
Personally, I beleive that for my purposes simplified is the only way to go because you shed the "fat" of the emmisions which I dont have to worry about anyway. If you need to keep emissions, and dont want to get completely engulfed in the system, then I would probally reccommend keeping it stock. As stated (I think) before its much easier to repair something stock, trace a diagram per manual, in the event of something horrible.