Discuss all things tuning in this section. News, products, problems and results.
Loving the material and course content HPA provides!
My EFI tuning test rig is a 95 Nissan bluebird KA24DE with a Nistune daughter board installed. If i break it it will go in the bin however motor has only done a healthy 100,000 km.
I am building my own turbo kit for this car and would love to learn about turbo manifold design and / or tips and tricks for forced induction on N/A motors. is this something you could cover?
My burning question at the moment is how far away from the exhaust ports can you mount the turbo before the turbo spool time is effected? I am using a Garrett T25 off a SR20DET.
I am looking at roughly 20cm with my current design and will be using heat wrap to try and reduce heat loss.
In the hobby level that we all tend to work in, it's unusual to be in a situation to try 2-3 different manifold designs to actually test the effect that an aspect such as runner length has in the real world. In general you'll find that your turbo location and manifold design will be more driven by packaging requirements than what could be considered optimal location/runner length, and the real world implications are probably less important than you think.
Unfortunately off the top of my head I can't offer you a decent resource on the subject. 20 cm is a reasonably short runner length though and I certainly wouldn't hesitate to build a manifold with that sort of length runner.
There are a lot of OEM exhaust manifolds that have runner lengths like that, or even shorter. For the most part, the trend that I have seen in OEM turbo packaging is to get the turbine wheel as close to the exhaust ports as is possible, to ensure the quickest possible response from the turbo. A lot also have semi external wastegate setup on the manifolds as well (especially those that have an integrated casting i.e. VAG engines) where they are bypassing a large percentage of the exhaust gases under boost, so that they can maintain a smaller turbine wheel with good response curves.
And then you have Subaru....
Thanks for the replys.... and like you say andre most are driven by package requirements... with this package aim being low cost and maximum education..... no mater when the boost comes on i will be able to but the tuning theory in practice....... my next car will be a subaru!