So just wanted a quick question answered for a design project at school. We need to pick a product that has been engineered to outperform a previous model, and then compare it with 3 other competing products. We chose to do turbochargers and specifically the new GTX-R models by Garrett.

So I just need three competing turbos from other manufacturers, and we were thinking of using the new GTX3582R as our benchmark, just from the random thread we came across here: https://www.rx7club.com/showthread.p...ht=garrett+gtx

I'm not too familiar with turbos and what makes two particular turbos similar, aside from a/r ratio, footprint, and size. So ideally, are there three competing turbos with the same footprint and relatively similar size as the GTX3582R that we can use?

Also, for clarification, the GTX-R models are basically upgraded re-engineered versions of the GT models of the same size right? For example, they would just make flow improvements by means of machined housings, billet wheels, more compressor fins, etc. ? (we need to explain 10 customer needs of the product, and we can explain how this new model outperforms the old model by means of better build processes and re-engineered parts of the older model)

Thanks for any info you guys can provide! I figured I would use school to learn something interesting at the same time!

Edit: So I've that comparing turbos can be done using the Inducer Size?

 

The only difference between the GT and GTX models is the compressor wheel. Everything else is the same. To simply you can just look for turbo's with the same compressor inducer to have comparison turbo's.

However, if you need to show a lot of improvements based on customer needs, maybe the BW EFR turbo line would be a better place to look as they made a ton of improvements / added features. (lighter turbine wheel, high flowing divided internal wastegates, triple ceramic ball bearing CC, integrated BOV, integrated boost controller, etc.)

thewird

 

Here's a question though. What kind of proof,evidence, or other data do you need to use for this project? You don't have the means to physically compare the products in an empirical way. You will have to rely on whatever you can find on the internet. Is that going to work? Is this for a mechanical engineering design project? Does the person who is grading this know anything about turbos?

Can you attach a .doc file or screenshot with the description of the project and its requirements?

 

I didn't know that, and was thinking there were some other differences but couldn't find any manufacturing-type info on the housings and such.

I've been doing a lot of reading on Garrett's turbo tech section - it's informative enough that I understand all the different sizing specs now so once I'm done comparing the GT to the GTX3582R I'll move on to the other companies; although I may scrap this comparison and choose a BW turbo as the main turbo if there is more than just the compressor wheel upgraded from the older design, like you said. I'll also try to compare ones with the same footprint, and same a/r ratios where possible.

I was thinking of displaying a compressor map to show where the mass air flow rates differ from the other turbos, since that is what is meant to increase with the improvements right? (ignoring the improvements in efficiency and choke and surge blah blah blah this-*****-confusing) But all technical stuff aside, the most basic factor in an 'improved' turbo is the higher flow rate through the compressor, which results in more air into the engine/unit time right?

Exactly, it's a relatively small project but nonetheless... all I can find from Garrett is the compressor map and the turbine flow rate graph. The compressor map may be fine if I can explain where the improvements are displayed.

It's for mechanical engineering, yes. The professor is an automotive engineer but looks as though he works more with structures than engine-related stuff. He has his own website http://www.ahmadbarari.com/

I've attached a pic of the project slide for the part I'm working on. This is turning into more than just a quick question but I've been getting carried away with learning about turbos for the afternoon today so thanks for the info. I'll start looking at the BW turbos and get back to you on my benchmark choice - it may turn out that the improved compressor wheel is enough of a improvement to compare.

One last thing for this post, as experienced turbo customers, what are some of your requirements when looking for a turbo. Try to base it on YOUR application to keep that a constant variable; so your manifold stays the same, your intake setup stays the same, downpipe, etc. Are you able to shop around for JUST the turbo, based on new improvements and/or other manufacturers competition, or is there typically more to change/upgrade with the new turbo? (the ease of replacement/upgrade is currently one of my customer needs)

 

Oh, other things the BW EFR turbo's have are stainless steel turbine housings, adjustable wastegate positioning and a compressor speed sensor port.

thewird

 

EFR product line is just an enlarged and tweaked version of the factory turbo on the VW 2.0T engine... it's a good product but it's not as groundbreaking as the marketing wants you to think

For purposes of this project maybe you should narrow it down to comparing flowmaps from compressor wheel of similar sizes (nominal dimensions, inducer and exducer). The wastegate, compressor housing designs, etc may make the assignment too large/complicated. Keep in mind that most manufacturers have flow maps in units of m^3/min or other such metric unit whereas Garrett uses lb/min , so you will have the messiness of unit conversions

Also, I'm not seeing the attachment

 

I'll just copy and paste it then, i didn't notice the file was too big to post.



Yea I read up on the product, but the website isn't as functional as the Garrett site. It's annoying that when you click on a couple of the EFR turbo data sheets they don't open.
Now the EFR turbos aren't directly replacing any of the BW turbos from before right? They are basically just a new introduction to the aftermarket lineup yea?(as arghx said, based on an OEM application) I read that BW EFR thread in this single-turbo section last night too and the link given there helps a lot.

I think the EFR will be a good choice because it has a lot of features that your BASIC turbo doesnt have like that gamma-ti compressor wheel, curved fins, billet wheel, etc. So it will be easy to identify the engineering solutions to the customer requirements.

For customer requirements I've got (just a stripped down version of my list basically):

high compressor flow rates
quick spooling response
able to withstand all applications within it's designed purpose
high efficiency rate
easily interchangeable as upgrade to older styles
compatibility with existing supporting components
resistance to surging, choking, etc.
access to manufacturer data before purchase
customer support for product
durability
able to upgrade/replace individual components
wide range of operating conditions (humidity, ambient pressure,etc)
low vibration, noise
low maintenance under regular operating conditions
size/compactness
price


If anybody wants to add to/take away from the list feel feel free, it's just an outline until I find out which requirements I can explain the best, relating them to features of the turbos and then explaining the engineering solutions behind the features.
I talked to the prof today about explaining all the little details and he said the more detailed the project, the better. As I explained it to him thus far we're definitely getting some bonus marks lol. Thanks guys.

 

I think the tricky thing here is trying to keep it narrow/focused because so much goes into turbos. If you are allowed to keep things mostly descriptive/qualitative then it won't be bad.

good but as I mentioned availability is spotty and manufacturers use different units

good but many factors are involved that are unrelated to the turbo itself so this could be complicated. keeping it just generally descriptive/qualitative is key

vague

inseparable from flow rate really. seems redundant

very important

vague, many factors involved, very application dependent as turbos are often modified in some way and sold in kits from 3rd party vendors. Rx-7's are small potatoes. Look at all the stuff people put on Evos and WRX/STi which are among the biggest markets for aftermarket turbos right now

if you are using those terms in the sense that they relate to a compressor map, this is redundant

good. Garrett usually has the most info available. small time vendors (like Forced Performance and Precision) are heavy on marketing and in many cases slim on data, probably as a cost cutting measure

complicated because turbos are sold directly through dealers (ATP turbo etc.) or through smaller vendors who may then do their own application-specific modifications to the turbo itself (changing housings, clipping the wheel, whatever. think HKS TO4Z versus regular Garrett T04Z)

seems redundant when you have "able to withstand all applications" which is in itself vague. durability is hard when you are dealing with aftermarket and custom/racing applications where there is no "normal use" benchmark

depends a lot on the dealer network

difficult to measure because compressor maps are done under standard operating conditions and engines themselves vary greatly

Good but this applies mostly to OEM applications

good in theory but how can you separate maintenance of the turbo from just general maintenance of a car (especially a modified one)? how could you measure this or at least discuss it

depends on whether all the little variations of housings are commonly sold through the aftermarket. For example, Mitsubishi-based turbos have a gazillion types of housings but mostly OEM's can get their hands on them and you can't buy stuff off-the-shelf as easily. Garrett's GT turbos can easily be bought in a bazillion combinations, just look at what atpturbo offers

good but the complicated network of dealer networks and suppliers make this tricky

 

Thanks for that ^ pretty helpful actually. I've got all the information I need gathered together now so it's time to organize and write. Thanks Thewird and arghx