Highflow twins

[John Yorke]

Some people claim improved power from seq twins, think most of it is the big surge in power at about 5k when the turbos kick in together, put them on the dyno and you will see no difference to stock, maybe a touch from porting the wastegate.

John Hudson:
What spec engine are you fitting these twins to? What are you doing to support this 1.4bar, that is a lot of boost for twins, The Hog ran his stock twins at 1.4, they lasted a couple of months and he had all the bits in place:rolleyes: Like I said run twins at more than a bar and you will have issues, there are much better ways of getting to the magic 400+

[John_Hudson]

i want to be at a safe 350 atw, mods are pfc 3" decat exhaust trust DP, apexi GT FMIC uprated alloy rad, profec b spec 2 boost controller, sard FPR 850 injectors all around apexi intake err cant remember anymore its to late... early.. damn night shifts :p
on a standard engine but that wont be like that for to long

i also wont be running high boost on stock twins, it will be on the knightsports 420\'s

[Neil_M]

Without being argumentative, surely "flowed twins" should remove some restrictions in the turbo system... Bare in mind I am saying some, so I could understand people saying the delivery can be a little different.

However IMO if you are providing flowed twins, they should be built to a higher spec.  Which in theory will allow a marginal increase in boost, while still keeping the turbos in a relative "safety zone".

John I do understand what your saying though.  With out direct experience of modified stock twins, I cannot claim any factual evidence, im more thinking aloud.

Does anyone have further details on boost pressures for the stock twins along with likely output (HP).

[andysmee]

From this thread, and similar and my own experience to date:
 
280atw+ @ 0.8bar
300atw @ 0.9bar
320atw @ 1bar
.
.
380atw @ 1.3bar

[John Yorke]

Without being argumentative, surely "flowed twins" should remove some restrictions in the turbo system... Bare in mind I am saying some, so I could understand people saying the delivery can be a little different.

However IMO if you are providing flowed twins, they should be built to a higher spec.  Which in theory will allow a marginal increase in boost, while still keeping the turbos in a relative "safety zone".

John I do understand what your saying though.  With out direct experience of modified stock twins, I cannot claim any factual evidence, im more thinking aloud.

Does anyone have further details on boost pressures for the stock twins along with likely output (HP).

Its not the turbos so much as the integral wastegate that is the cause, more boost you push through the restriction [read wastegate] the more heat is produced the less productive the turbo\'s become, yes you can run 1.3 but they dont last long, BNR\'s Knightsports ect still run through the same system and yes you will see gains but its not an effective way of tuning, just look at all the rotaries in the UK that run over 320 99.9% are singles, twin singles now that is something worth looking at and with the twins you are still reliant on that wonderfull rats nest:eek:
Dont know how much you are paying for these Knightsport turbos but me, I would be looking at running them seq. and porting out the the wastegate manifold you wont see the early boost but will have more usable power, running them on a stock engine wont see the power you are hoping for, 850\'s all round may not be enough fuel for 350 either. Hth

[John_Hudson]

they will be converted to full non seq.

price for the turbo\'s are 600 including shipping but excluding import tax