Hi
Can some one kindly explain to me the difference between non sequential turbots and sequential turbos.
I have 96 RBBathurst jap import and am I correct by saying that I have non sequential turbos ?
Am I also correct in saying that the first turbo kicks in at around 3k revs and the seconded one some point later 5K?
I remember the car being a touch faster in the upper revs before….I can defiantly feel the turbo kicking in at around 3k but not much happens later on while I am in second gear say at around 5/6k. It almost feels like I am pressings the pedal and the revs are going up to slow along with the car. The boost is hitting around 0.75 / 0.8
When I am in 3rd at around 5/6 k all is fine
The clutch is only 5moths old but I have had no service for a year now (spark plugs?). I will go to Rotechnics very soon; unfortunately every time I go there I came out with very little change from 1k
Any thought? It is not that bad but I know the car and it seems slower…
Regards,
Michaelb
You should have sequential twins unless they\'ve been converted to run together all the time ie. non sequentially.
First turbo cuts in at about 2.5k rpm , then a slight lag as the second joins in at about 4.5k rpm.
You should feel a very big power gain and kick in the back at 4.5k rpm.
Sounds like a pipe in the rats nest may have popped off and your secondry turbo isn\'t coming in. Do you have a boost guage? Pattern should be 10-8-10 psi. (0.7-0.6-0.7 bar)
Your turbo\'s are running sequentialy,that is one at low rpm and the other then joins it at higher rpm.
The second turbo sounds like it is not working properly.
It can be alot of things,either a pipe has come off or a solenoid has stopped working in all likely hood.
Regards
Carl
Make sure your engine oils\' changed every 3K. Any monkey garage and to this.
QuoteI will go to Rotechnics very soon; unfortunately every time I go there I came out with very little change from 1k
That\'s Rotechnics for you :p
Hi
Thanks for the replay. No idea wht is "pipe in the rats" where is it ?
I think I get the boost 0.7 - 0.6 - 0.7. I looked at the boost guage this morning but it is wet now. I will check again Tommorow wether permiting..
No major kick at 4.5 revs but still car goes very fast..
Regards,
Michaelb
Quote from: TrevrxYou should have sequential twins unless they\'ve been converted to run together all the time ie. non sequentially.
First turbo cuts in at about 2.5k rpm , then a slight lag as the second joins in at about 4.5k rpm.
You should feel a very big power gain and kick in the back at 4.5k rpm.
Sounds like a pipe in the rats nest may have popped off and your secondry turbo isn\'t coming in. Do you have a boost guage? Pattern should be 10-8-10 psi. (0.7-0.6-0.7 bar)
Hi Carl
I hope you are well.
I actually would not mind trying your garage for the service and possible turbo issue.
I always spent so much at Rotechnics….
I need oil filter and oil changed, spark plugs, air filter cleaned or changed and petrol filter changed ( had it changed a year ago, may not need to )
Can you pm me with quote for the service or would you prefer if I call you ?
Regards,
Michaelb
Quote from: CarlYour turbo\'s are running sequentialy,that is one at low rpm and the other then joins it at higher rpm.
The second turbo sounds like it is not working properly.
It can be alot of things,either a pipe has come off or a solenoid has stopped working in all likely hood.
Regards
Carl
Something iv\'e always wondered is at what revs non seq twins start to boost, is it at the revs the first normal turbo would normally spool at, say 2500 or when the second turbo would have kicked in at say 4500? or in between i am thinking og going non seq, as i can\'t seem to drive at over a 100 anywhere, and figure i would get more use from the second turbo lower down the rev range, any advice, please, sorry to highjack michael, sort of related,
Bob
If you go non sequential you will get LESS boost at low revs. THe whole idea of sequential is to send all the exhaust to spool up the 1 st Turbo at low revs.
And if you go non sequential you dont gain anything at high revs either. The only benefit of non-seq is you dont have the slight dip in power during transition.
Thanks for clearing that up for me Martin, i think i will have to learn to welly it a bit more,not redlined it yet!
Bob
My car also feels very similar to this, there is quite a lot of power there and I can feel a slight power increase when the second turbo comes in I\'ve been meaning to change all the pipes under the plenum.
What else should I look at while I have it all apart how do I check the solenoids or is there an order to start checking these things.
Alan