Non Sequential Conversion

[Martiny]

I dont think Higher top-end is possible. In the stock setup you have both turbos on-line. And its the same in non-sequential, so could someome please explain how this is possible?

QUicker response is also not correct. you will have MORE lag with non-sequential rather than less.

The fuel economy gains are only a result of losing a lot of boost at low revs.

Take note of smifta\'s comments, "its not as fast around town". THis is because what you are doing is removing the primary turbo\'s ability to supply air at low revs, so you lose torque.

Unless you are have turbo problems, I cant see the point of doing this conversion.

[Rixio]

The points above are what i got from various forums & links...i think the more responsive is only if its in the correct gear but yes you do lose low down torque. Fuel consumption should be much lower because you dont have to push the car as hard to get somewhere. I do drive around town alot but when it comes to open country roads which it was designed for this works better me thinks

Martin its the next step forward towards going single so thats what i wanted to do initially but because of the whole job status i havnt done...whilst the car is in bits because of the overheating i thought id get it done at the same time so theres less to go wrong when something does

Its a pretty erratic boost curve on mine so i wanted to smoothen it out a little aswell, my GTC was stock and after driving this & then that a few minuts later i envied the smoothness

Anyway im doing it now along with all the coolant pipes so will keep everybody updated

P.S They said they had problems with the collection truck so have refunded me and going to collect this Fri

[Martiny]

Sorry, but the forums and links are talking cr4p if they tell you you are getting more top-end.... it will be the same.

As long people realise they are compromising low end responsiveness and low end power, then its fine.

Yes, its also a way to make the boost curve smooth, as you are removing the transistion from Primary to Primary + Secondary.

:-)

[John Yorke]

Having gone down the non seq. some 3 years ago you will not find any more top end power doing back to back dyno runs prooved that to me it was within 1hp.
On stock twins you will find it much more laggy - even more so than a huge single, I was quite dissapointed TBH, couldnt wait to go propper single, on the plus side you get rid of a load of controll gear which is a good thing:yes

[Shyne]

Main points have really been covered in the last 2 posts for my money, although, you can increase top end power, BUT!!!! this is only because you can freely and more simply up the boost (Boost controller needed on NS really!) but at the end of the day, I see where Martin and John are going as you are still using the same HT12 snails and the capabilities of the configuration will not change.

As for lag, it comes back to tuning and manifold prep, but you WILL increase lag from the primary turbo as you no longer have control of the "gate" in the secondary exhaust tract(for one!).

I went straight for the full conversion as I wanted to mod the twins before fitting and the main approach for me was cooling for the engine as it would be needed for my driving style (next mod was wipers on door windows!) as would constan and easily adjustable boost, the transition was very annoying for me and I felt it held me back on the throttle when cornering.

Summary: I loved NS, but you REALLY need to know why you\'re going for it and what you want from it in the short and long term.

It gives good experience for tuning the single when it comes along (which it will for Rixio in my opinion)

Best of luck fella

[Rixio]

Iv actually decided not to go non-seq for the time being. mainly because i dont want to mess anything up. I need to get the car running properly again without it overheating first. Then i\'l decide what to do about the conversion. It doesnt look like a big job in any case...so watch this space

[DC-TYPER]

I thought the sequential setup was - small turbo spools up big turbo, thus preventing lag and having smooth accelaration.

[John Yorke]

I thought the sequential setup was - small turbo spools up big turbo, thus preventing lag and having smooth accelaration.

Sorry fella both turbos are the same size:o

[DC-TYPER]

So Is It As Simple As One Blows Then The Other, Or One Blows And The Other Joins In?
 
Had The Car 9 Months And I Still Aint Got A Clue

[John Yorke]

One blows, pre-spools the second and the 2nd kicks in:Snoring

[edgasket]

there\'s no difference in them at all, its just the solenoid controls that reduce the lag?

[John Yorke]

Think of it as a two stage turbo - 1st half boosts whilst the other half pre-spools when it is up to speed @ about 4.5k it comes on line. By making them non seq. they both come on line at the same time so therefore take longer to spool.

[trotter]

Thats what my understanding of it was...having sequential turbos eliminates (reduces) the problem of lag. ie: instead of having boost from the first turbo and then having to wait for the exhaust gases to spool the second, the first pre-spools the second and cuts out the afore-mentioned wait.

On this subject though, when the second turbo kicks in, is the first still blowing?

(I understand how single turbos work fine, but sequentials are a bit of a head scratcher to me im afraid so pls dont take the p!ss! :Hammer )

[Martiny]

Yes, the 1st blows all the time. The second is "added" in after 4.5 k

[Devil\'s Refugee]

Is it possible then to have one larger than the other ??