How smooth should the transition of power be between 1st and 2nd turbo\'s?

[chrisBoid]

Went for a blast on Sunday (just before the rain hit) to check out my turbo boost pattern, as I hadn\'t done it since getting a boost gauge installed :rolleyes:

Anyway all was fine, but I remember reading (perhaps in RX-7 Performance handbook) that the transition of power between 1st and 2nd turbo\'s should be smooth; is this correct?

Mine isn\'t smooth, more kick in the back - I\'m not complaining mind

FD, stock twins, aftermarket induction, aftermarket exhaust pipe.

Thanks

Chris.

[20B_boy]

On the stock computer the transition varies a lot between cars, and it gets smoother as things wear in my experience Its one of the things I like about a GOOD tight stock FD, waiting for the slap in the back and the rear end to snap loose out of junctions ;-)

A Power FC and mapping tends to smooth the transition out *a lot*

If you compare dyno plots before/after programmable computer and mapping you\'ll see that the activity across the turbo transition is much smoothed...

HTH

[John Yorke]

Hi Chris

You should find readings of 10-8-10 or similar dependant on the age of the car 1st turbo is operational up to 4.5k where 2nd turbo [pre-spooled] kicks in, you should feel a slight hesitation on transition.
To get it smooooother go for an after market ecu or go single:bandit
Hope this helps
John
PS boost patern should be even ie: 1st turbo should have the same reading as after transition.

[chrisBoid]

Thanks guys.

Yep the pattern is right on the money 10-8-10 There is the slight hesitiation, always good for building the anticipation I say

Don\'t get me started on aftermarket ECU\'s and big singles :p they are all I can think about at the moment!  It\'s a case of when, not if

[20B_boy]

Originally posted by chrisBoid
Don\'t get me started on aftermarket ECU\'s and big singles :p they are all I can think about at the moment!  It\'s a case of when, not if

GOOD MAN!

[iaint]

As mentioned the addition of a mapped ecu will smooth out the transition.  If you still have a cat it could be lack of flow that increaces the the drop between turbos - mine got worse and worse until I de-catted.  Now it\'s almost unnoticable.

Iain