I understang the basics of gas flowing and port matching and I\'m doing a bit of work on my inlet manifold and turbo while the engines out
I have one question though , regarding the exhaust manifold to turbo housing ports , if I enlarge the housing port to match it as near as possibleto the manifold port will this slow the gas flow down and increase spool time due to a larger void for the gas to fill or will it increase gas flow and decrease spool time due to a more open flow path ????
Ok, Exhaust ports,
There is not alot you need to do to the Exhaust Port, this is one of the things you have to be carfull with, You can open the Port its self up but on a street car just open it up so you remove the OE Chamfer make a Rad on the opening edge and a Small one on the Closing (just so its not Straite) then recut the 2mm
Chamfer in the closing edge.
This is about as big as you can go without causing overlap, or effecting your Expansion run.
You can\'t open the Sleeve up as its not very Thick, so all you can do is smooth the Housing to manifold jump out.
Be aware that you don\'t want to make the Port too Wide as the Apex seal is more likly to make contact with the closing edge of the port at high RPM.
This is kind of what it should look like.
I\'m leaving that porting for an expert , the bit I\'m planning on doing is the exhaust manifold to turbo housing
I\'ve attatched a couple of pics of the offending items , incidentley the cracking on my turbo is quite similar to this however I reckon I could grind most this away if I matched the turbo housing port to the exhaust manifold as best as possible
TBH if i was you i\'d replace the manifold with a good one then work with that, if you just grind the damaged bits out you never know how deep the Cracks go and if they will be back.
The manifolds actually fine its the turbo housing thats cracked , Pips said he can supply me with a new (used) set of twins in good nick but I thought if I coulod get away with mine its another saving in a very stretched budget
So do you think this is worth a shot and what would you think the results would be in rgards to spool time , obviously I want the turbos to spool as fast as poss , I know theres going to be more lag compared to the sequential system but I don\'t want to add even more
I\'m guessing no-ones actually done this as I\'ve posted this question twice now , here and in my non sequential questions thread and your the only person with any feedback so I\'m guessing its all down to theory
Yep its defo a Theory one.
TBH i\'d be searching the US forums to see if its been done?
I know this much, on the exhaust, i\'ve run a T2 with no sleeves in with a very large Exhaust manifold and it did\'nt make as much of a Diffrence to the spool as i thought. What does make a diffrece is Cracks round the Wastgate and damage to the turbine Blades. (or over clearance)
It was actually off one of the US forums that I got the pics and thats when I started thinking about matching the poerts aswell as cutting the bridges out
I\'ll do some more digging , if you think of owt give us a shout
I suppose the only way to find out for sure is get another turbo pack and manifold then match one and not the other and stick it on the rollers or a bench dyno that would make it alot easier to swap them over