diy D-series turbo

We may earn a small commission from affiliate links and paid advertisements. Terms


well, I Not gonna even try to get everything I posted on the previous forum...but to update everyone...My 14g came back from turbonetics looking sweet, I got my dsm 450cc injectors(need 4g civic injector resistors), I ported my std manifold to match a D15 exhaust manifold gasket and then polished it to a glass smooth surface, I am currently opening up the compressor outlet(it's I.D. was 1.75" making it a smooth transition to 2") and the turbine outlet and wastegate. Please before Tuesday if you need more info refer to the old forum. I will try to get the Turbo flow list back on.and again(fer the 3rd time) I have compressor flow maps, and the math formula's so feel free to email me....
Originally posted by turntune@Sep 29 2002, 09:05 AM
okay but only once...PAY ATTENTION!
airflow rate: cid x given rpm x 0.5 x engine efficiency(.85sohc'.9dohc)divided by 1728 wil give you an engines airflow rate
pressure ratio: 14.7 boost psi divided by14.7
now take your airflow rate number and multiply it by your pressure ratio number. that number gives you the cfm requirement at a given boost psi.

fyi...the .5 in the airflow rate is due to the fact that a 4-stroke cycle engine fills its cylinders on half the revolutions

i thought this would work good here
fuel management is going to be Zydne, when they release the 5g civic application.
Until then I'm gonna try the S-AFC by APEXi. I'm only gonna run a max of 6psi until the ecu exchange, but I'm hoping it will allow me to gently find the problems I'm gonna encounter with higher boost. Everyone please remember this project is done on a very strict please don't tell me how I'm doing it all wrong....Any who...
so now I'm working on function and efficincy. The 14g has a turbine housing similar to a 14b, other than the wastegate output is blocked off by a plate, and is connected via a port to the turbine outlet. problem lies in the fact that the wastegate becomes very in-efficient, allowing boost to creep,bad.I would use a 14b downpipe but the turbine housing is machined in such a way that the union would leak,bad.Solution, I sepperated the turbine housing and machined the wastegate seat to allow more control over boost levels,and then ported the wastegate opening and blended into surroundings,this will allow a cooler, more efficient wastegate,good.
and thangs for the archive! :)
Brian, was maybe thinking the Zdyne route...but still up in the air.
Just finished the turbine housing, came out very, very nice.Next is the compressor housing.quick question...the wastegate actuator that came with the turbo has 3 ports on it...anyone know why?...and for what?...I did find out that the diffference in the 87 dsm upgrade 14g and the 88-89 was the wastegate actuator...I think it's preset to 12psi but am unsure,either way I don't think I'll use it on account I don't want to push more than 6-7 psi on a stock bottom end....
I'm using the 88-91 civic STD manifold...not the hf, the has larger ports and allows more machining. as for the dsm manifold...I dont think it will, otherwise more people would be using it instead of having to make adapters to mount the turbos the the civic manifolds. the std manifold is identified by the large 3 on the far left runner