MD214 Turbo

[skiddusmarkus]

Roller Bearing turbo, special 54mm GT25 76 trim turbine, high flow 76mm T04S compressor wheel (53mm inducer), re-profiled compressor housing, choice of uprated actuator, and modified wastegate.

How come when I check the specs for my turbo it has bigger turbine and compressor wheels than units like the GT2871R and HKS 2540 and only has a slightly smaller turbine than the HKS 3037 but larger compressor but is physically the same size as the standard T28 and rated for less power?
The other turbos mentioned are larger and come with bigger diameter inlets.Obviously the housings are machined more on mine for the wheels to fit.
Is it just down to the A/R?Is there a larger gap between blade and housing on the other turbos?[/quote]

 

[stevepudney]

Is it just down to the A/R? Is there a larger gap between blade and housing on the other turbos?

You hit the nail on the head there Simon, after long chats with Craig at Turbo Dynamics I think we sussed out the 214 with the .86ar turbine housing would be around the same spec as a 2835 Pro (I think), which is only a tad different to the 3037.

 

[Edd]

I think its down to more than just the A/R though

for example i was chatting to a bloke wth a GT35 at PTS and he had a 0.84 A/R on his and it made me think hmmm mine has an A/R of 0.86 so surely mine would make more power..........his is scheduled to push 600bhp plus
However you look at his turbo and his compressor housing is 1.5 times larger than mine.

I think he said something about the A/R being relevant to the turbo and not something you can compare across turbos

As an aside it'd be interesting to see on same engine the pwoer produced at 1 bar with md214, 3037, gt35 and whole other turbos and see what difference is made

 

[Odin]

I have that jgy 37R turbo and I don't think it looks much bigger thasn the old T28 but it's supposed to push out more than 500bhp, So as the nun said to the bishop size dosen't matter :lol: :lol: .


rob

 

[Hkondakci]

The main thing with turbo's that makes power is the inducer and exducer size of the compressor wheel (+ trim, which depends on inducer and exducer sizes). Also the shape of the blades and the count of the blades. Then there is the size of the compresoor housing and the inlet of the compressor housing that matters.
On the turbine side the same is applicable for the turbine wheel and housing. There the A/R stands mainly for how laggy the turbo will be and on what capacity engine it will work best (read small A/R is better for smalle engines, and larger better for bigger ones; roughly said). But A/R is not an absolute fugure, it is turbo housing specific parameter. On the bigger turbo's meant best for a 2L power plant you'll notice that 0,86 A/R is quite often used and is efficient.

A/R describes a geometric property of all compressor and turbine housings. Increasing compressor A/R optimizes the performance for low boost applications. Changing turbine A/R has many effects. By going to a larger turbine A/R, the turbo comes up on boost at a higher engine speed, the flow capacity of the turbine is increased and less flow is wastegated, there is less engine backpressure, and engine volumetric efficiency is increased resulting in more overall power

Most important with good working and effcient turbo's is that the wheel sizes and housing sizes are good mated to eachother. The wellknown bigger Jap brands like HKS, GReddy and Apex'i have really good working and efficient turbo's. They will not use almost 80mm compressor wheels with some more than 50mm big turbine wheels; this will generate big volumetric inefficiency for the engine; the engine will be really stressed when boost is wined up, nog good Also not to good for power outputs too. The newly designed Garrett GT series turbo's are very well crafted and there price is quite competetive.
When seeking for 500HP the compressor must be around 76 to 80mm and the turbine wheel around 60mm. A tipical 0.60 A/R compr housing with a 0.86 A/R turbine housing. Here the compr map of a efficient and good 500hp+ turbo: http://www.atpturbo.com/root/maps/gt30r.htm
On this site there are compressor and turbine maps available for the most turbo's. Quite handy when picking the right blower for your application.

rgds
habib