Jump to content
SAU Community

Recommended Posts

Skyrine-Dave, I was also under the impression that the designation R was used for a hybrid turbo with different spec compressor and turbine.

Garrett dont use naming conventions like GT3040 as such - perhaps this is something started by the local turbo manufacturers to cash in on HKS's popularity? From what I was told the GT series just use the first two numbers ie, GT30.

This is what I was told by a turbo shop anyhow.

  • Replies 96
  • Created
  • Last Reply

Top Posters In This Topic

Garrett dont use naming conventions like GT3040 as such - perhaps this is something started by the local turbo manufacturers to cash in on HKS's popularity?  From what I was told the GT series just use the first two numbers ie, GT30.

Bingo! exactly what i reckon. As for the 'R' just download the Garrett pdf and it states all.. If my acrobat would let me select the text i'd copy it word for word

Here is an image from the pdf... will edit post when i find pdf online

EDIT: here's the link to the latest pdf... I advise you right click - save target as... it is pretty big and takes a while to load if you just click the link :(

http://www.turbobygarrett.com/turbobygarre...7%2017%2013.pdf

Hi drunkenmaster, I have a few questions;

The RB30DET, is that with an RB25DET top end, RB25DE top end or RB26DETT top end?

If you used an RB25DET top end, do you still have the standard turbo?

What are you going to use the Zed car for?

Is your power target really only 250 rwkw?

The compression ratio of 8.3 to 1 and 1 bar target boost, are they correct?

What engine management are you using?

What boost controller?

With these answers I can give my opinion.

The RB30DET, is that with an RB25DET top end, RB25DE top end or RB26DETT top end?

RB25DE

If you used an RB25DET top end, do you still have the standard turbo?

No

What are you going to use the Zed car for?

Road car with light recreational track.

Is your power target really only 250 rwkw?

I beleive so, in a 1000kg car I think it should do fine.

The compression ratio of 8.3 to 1 and 1 bar target boost, are they correct?

Yes

What engine management are you using?

Undecided, most likely autronic SM2

What boost controller?

Like wise.

Background:

I am building the car from the ground up, over the last 6 monthes I have stripped the car to a shell, had it sandblasted on a rotisserie, now it is at home with the engine bay and interior painted only and the RB30DET has just arrived home from the engine builders. I have to finish off work on completing my garage/workshop so this gives me some time to do some research/shopping etc.

I could have bought a GTR with the projected cost of the project, so understandably funds are starting to slow down now and hence the interest in running an internal gate and saving $2k of manifold and gate.

Thanks for your help.

Thanks for the answers to my questions, my 20 cents worth follows;

Don't be concerned with the weight versus power, we have an 1180 kg R32 GTST with a bit over 400 rwkw. So 1,000 kgs with 250 rwkw is a no brainer.

I understand your reasons for going internally gated. The compression ratio and boost target don't really suite a HKS turbo, so I would go with a Garrett. My new turbo choice would be a GT25R, they are good for 450 bhp (270 rwkw) and cost around a $2,500.

In the used area, Japanese Motorpsort had T04E kit (turbo, manifold, wastegates) for $2,600 a few days ago. So it might pay to check around, as even if the T04E is totally stuffed they are a cheap ($600) full rebuild. GCG had a used (fully reco'ed) T04E (internal wastegate) for $1600 (turbo only) when I was there yesterday, so that may be an alternative as well.

With the SM2 you can adjust the boost rise, so I would not be concerned with violent power increases. You can soften it up with a few keyboard strokes.

Hope that is of some help

Thanks for the input.

Does the GT25R flange suit the RB manifold? I had thought (with no evidence) that the GT25's were matched to the SR series.

The decision i have to make is that the GT3540 i have in mind is new and around the $2k mark.

I also had a look around and both horsepowerinabox and UAS offer bolt on upgrades which look like standard turbos with GT cartridges, also UAS have the internally gated GT3040.

There seems to be too many choices to do the same thing.

Does the GT25R flange suit the RB manifold? I had thought (with no evidence) that the GT25's were matched to the SR series.

The decision i have to make is that the GT3540 i have in mind is new and around the $2k mark.

I also had a look around and both horsepowerinabox and UAS offer bolt on upgrades which look like standard turbos with GT cartridges, also UAS have the internally gated GT3040.

There seems to be too many choices to do the same thing.

Hi, you can get GT25R with T3 flange. I am sorry, but I am now confused, I asked......

Is your power target really only 250 rwkw?

You replied....

I beleive so, in a 1000kg car I think it should do fine.

If you had said that your target was really 300 rwkw then I would have recommended the internally gated GT3040. If you had said your target was 350 rwkw then I would have recommended the externally gated GT3040. The reason for externally gated is that I have a rule of thumb, I don't use internally gated single turbos over 300 rwkw. Their response and boost control becomes questionable.

So I don't think there are too many choices, if you want 250 rwkw then GT25R, if you want 300 rwkw then internally gated GT3040, if you want 350 rwkw then externally gated GT3040 is the go.

Or have I missed something?

All of them will, whether there sheer size will foul up against anything is another matter and whether you want/need and external gate will also dictate whether you need a new manifold.

Half my dilema above is the fact I cant really stretch the budget another $2k for a new manifold and external gate when my project is already running $10k over budget.

Always lots of confusion here . Most Garrett Ball Bearing Turbos (GT)'s have a two or four digit number , eg GT30R . The 30 denotes GT30 series exhaust turbine . It could also be called GT3037 because it has a GT30 turbine and a GT37 compressor wheel . There are exceptions to this eg HKS GT2540 has a GT25/28 series turbine with a TO4E compressor wheel . Some firms such as ATP Turbo in the US have come up with numbers like GT2871 and GT3071 to be difficult . With the last two the second two digits means 71 actually 71.1mm diameter compressor wheels which are GT35 wheels . So a GT3071R could be called a GT3035 by some .

Be very careful with GCG and Ray Hall as they are selling turbos they call GT30's and GT3037's which use old outdated TO4S compressor wheels (1976 vintage) which are the same family as the old 60-1 or 409535-1 as the part number goes . These wheels are seven full and splitter blades and were designed to pump large volumes of air at medium pressure ratios ie one bar or 14.7 psi . They take more shaft torque to drive than the later 97 era six bladed BCI-18 compressor wheels and impart more heat into the inlet air . This shows up as lag (caused by slip losses at the turbine) and increased charge temperatures .

The latest theorys suggest that sizing the turbine and comperssor wheels nearly the same makes for similar tip speeds . If properly sized (both) this increases the engines volumetric efficiency and allows it to produce more torque per pound of boost than the current crop of mis-matched turbos .

Always remember that aftermarket turbos are only a very small part of Garretts business and OEM are where the volume sales are at . Turbo development is an on going process and there are good things in the pipe line . Look at Australia as a backwater for these things and look to the US for the latest stuff . ATP Turbo.com shows details of most of the latest GT-R (not Skyline) series Turbos and the GT28RS and GT3071R seem to be along the most modern lines .

Chow A .

The price difference between a tO4E and a gt3040 is quite significant.

-What differences would be noticeable while driving on the street between the 2?.

-Would the boost come on at the same rpm with both turbos.

PS: For a rb30det:

*power fc and boost controller

*1200 kg car

*300 rwkw

*external wastegate

*factory rb25det exh manifold.

Sydneykid, i'm confused.....

My new turbo choice would be a GT25R, they are good for 450 bhp (270 rwkw) and cost around a $2,500.

According to the Garrett catalgoue, a GT25R is only good for 250 bhp. It has a max air flow of about 26 lbs/min at 1 bar. I thought an RB30DET would peak at about 35-40 lbs/min, but i'm tippin' i've overlooked something :)

There is a GT28 turbo that depending on who you talk to is rated at either 290 0r 320 hp . This item is a common upgrade for CA18's and SR20's and I think is the one in the catalogue .

The one you are after has a 71.1mm TO4S wheel in it and depending on the trim is rated at 350 , 400 , 450 hp . None of these has stellar performance , mainly because of the mis-match between the turbine and compressor major diameters ie 53.8mm (turbine) and 71.1mm (compressor) . When you look at the GT3071R it uses a GT30 84 trim turbine (60mm x 55mm) and a GT35 56 trim (71.1mm x 53.1mm) compressor wheel . Its turbine has very high flow capabilities for it s size , and its compressor wheel is three generations more modern than the TO4S . The compressor is rated at 44lbs/min flow which equates to about 450hp . The turbine is a late high tip width UHP (ultra high pressure ratio) and in a suitable GT30 housing has supported 500 plus hp . The GT3071R is being sold by ATP Turbo.com in the US and if enough people start to demand later technology it will turn up here too . Don't even bother with Garrett in Sydney because they've probably never heard of it and are not interested . Obviously it's easier to sell outdated technology to the un enlightened .

Hope this helps A .

The price difference between a tO4E and a gt3040 is quite significant.

-What differences would be noticeable while driving on the street between the 2?.

-Would the boost come on at the same rpm with both turbos.

PS: For a rb30det:

    *power fc and boost controller

    *1200 kg car

    *300 rwkw

    *external wastegate

    *factory rb25det exh manifold.

The TO4E is not really the equal of a GT3040 . Most TO4E wheels have a major diameter of 76.2mm (3") while the GT40 wheel is I think 84mm , higher flowing and more efficient (generates less heat through better design) . To match the GT30 turbine you would have to use an old heavy TO4 O or P trim turbine . So more innertia to over come and less efficient air pump plus the legacy of bush bearings and thrust plates to lunch .

If you seriously want 300rwkw I would look for a GT3240 , or if boost response is a priority use a GT30R with the larger 1.06 exhaust housing and a large external gate . These things don't come cheaply , but offer you a better chance of achieving your goals reliably and less chance of anihilating your engine .

Have fun A .

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Very decent bit of kit. Definitely black it out I reckon.  
    • Because people who want that are buying euros. The people with the money to buy the aftermarket heads and blocks aren’t interested in efficiency or making -7 power, they’re making well over 1,000hp and pretty much only drive them at full throttle  best way to way make money is know your customer base and what they want and don’t spend money making things they don’t want. 
    • It's not, but it does feel like a bit of a missed opportunity regardless. For example, what if the cylinder head was redesigned to fit a GDI fuel system? It's worth like two full points of compression ratio when looking at modern GDI turbo vs PFI turbo. I'm pretty reliably surprised at how much less turbo it takes to make similar power out of a modern engine vs something like an RB26. Something with roughly the same dimensions as a -7 on an S55 is making absolutely silly power numbers compared to an RB26. I know there's a ton of power loss from things like high tension rings, high viscosity oil, clutch fan, AWD standby loss, etc but it's something like 700 whp in an F80 M3 vs 400 whp in an R33 GTR. The stock TF035HL4W turbos in an F80 M3 are really rather dinky little things and that's enough to get 400 whp at 18 psi. This just seems unwise no? I thought the general approach is if you aren't knock limited the MFB50 should be held constant through the RPM range. So more timing with RPM, but less timing with more cylinder filling. A VE-based table should accordingly inverse the VE curve of the engine.
    • I've seen tunes from big name workshops with cars making in excess of 700kW and one thing that stood out to me, is that noone is bothering with torque management. Everyone is throwing in as much timing as the motor can take for a pull. Sure that yields pretty numbers on a dyno, but it's not keeping these motors together for more than a few squirts down the straight without blowing coolant or head gaskets. If tuners, paid a bit more attention and took timing out in the mid range, managed boost a bit better, you'll probably see less motors grenading. Not to name names, or anything like that, but I've seen a tune, from a pretty wild GT-R from a big name tuner and I was but perplexed on the amount of timing jammed into it. You would have expected a quite a bit less timing at peak torque versus near the limiter, but there was literally 3 degrees of difference. Sure you want to make as much as possible throughout the RPM range, but why? At the expense of blowing motors? Anyhow I think we've gone off topic enough once again lol.
    • Because that’s not what any of them are building these heads or blocks for. It’s to hold over over 1000hp at the wheels without breaking and none of that stuff is required to make power 
×
×
  • Create New...