T60-1 vs GT30r
 

hi...i compared the specs of the wheels of the garrett gt30r and the t60-1 and i saw that they are almost the same...it has been told on the forum that the gt30r is too small to run on our cars...but wouldnt the t60-1 fall into that same category?...

what are the specs of the apexi rx6?...i heard they are not rebuildable...but arent the garrett turbos like the gt35r non rebuildable as well?

what makes the gt30r too small to run on a rotary is the hotside. the turbine wheel, if i recall correctly, is slightly too restrictive for the rotary and the turbine housing is T3 footprint. as far as i know, the 30r compressor (3076r=76mm?) would work just fine, but the hotside wouldn't.

The hotside of the smaller GT series turbos like GT30R is too restrictive for the high overlap rotary as it is designed for 4 cyl engines.

60-1 is available with a huge range of hotsides as it was re-designed for use on everything from 4 cyl to 8cyl engines.

But the compressor of the GT30 is also far from ideal for the rotary as it is designed for efficiency and flow at high boost as a modern 4cyl engines require and so do not provide good efficiency at low boost and high flow levels.

60-1 was designed back when piston engines needed the efficiency and flow at the low levels of boost like the rotary requires.

Look at the maps. Say you want a 13B w/ 400RWHP at 14.7psi like everybody else has w/ a decent turbo set up.

60-1 is flowing the required 53 lbs/min and pressure ratio of 2 (14.7psi boost) at over 70% efficiency and under 100,000rpm.

GT30R is off of its efficiency map in the 60s % and over 100,000rpm at the required 53 lbs/min and 14.7psi boost.

You actually have to do 23psi boost w/ GT30R to get the same flow and efficiency as the 60-1.

Which is great on a low overlap engine because you HAVE the same efficiency at higher boost level, but on a high overlap engine the increased boost pressure causes much more exhaust backpressure which hurts the ENGINE efficiency and introduces more chance of detonation regardless of compressor efficiency.

Now, the GT35R has a compressor map comparable to 60-1 for flow at low boost levels and has more efficiency at high boost levels if you want to run race gas, ethanol or aux injection. GT35R also has some larger exhaust sides available thanks to rotary enthusiasts.

Downside t GT35R is cost, availability and ability to rebuild over a 60-1, but the Turbonetics ball bearing T60-1 and ball bearing Garret T04S (60-1) suffer from this compared to another T04 w/ 60-1 compressor as well.

good info

If we are talking GT3582R and GT3082R, then they have identical compressors, so there will be no difference in flow potential due to compressor. They might be more back pressure between the turbo and engine, and it will operate closer to the surge limit.

could you run a 60-1 on a half- bridge? It wouldnt be for abolute peak horsepower, but for a good responsive setup?

The T60-1 is better suited for the rotary. That said, I've always thought a GT30r with a t4 turbine from a GT35 would be interesting to try on a 12a.

Firstly you should read my first post again...

If you chose the GT3082R, as I said, IT USES THE EXACT SAME COMPRESSOR WHEEL AS THE GT3582R. Why would you would want the larger rear turbine is beyond me. Its no coincidence that the second 2 digit number in the full part number is '82' standing for 82mm front wheel.

There is an Australian race car built for Improved Production racing that has a 13B Turbo, and has to use a 34mm restrictor in his intake. He is using a GT2871R, which I am led to believe is the same rear wheel as a disco potato, with a 71mm front wheel on it from the factory. The rear wheel on the GT28 is actually smaller than the standard s4/s5 turbo. The 'guts' of the GT2871 were put into the standard rear housing of the mazda turbo. The rear housing was slieved, and then machined to look like the standard GT28 rear.

He found that it could make 180rwkw @ 4200rpm using 21psi, but he opted to run 17psi, because that allowed him to make flat boost from 4000rpm to 5000rpm. Apparently it didn't make much more power than 180rwkw, and largely ran out of puff past 5000rpm. But still it worked, and is a very fast non laggy setup. He said it had less lag than a standard s4/s5 turbo. If this guy can get all that to work, there is no reason why a GT30 rear can't be used to get something in between the GT28 and GT35 powerband.

When I buy a turbo I'm thinking about getting something a bit out of the norm.

i just found the 30R in a T4 flange! it only comes in 1.06 a/r but if someone really wanted it they would have to make due with only one choice. i was surprised to see it recently, i might have gone with the 30 instead of the 35 but meh i'm happy.

http://www.atpturbo.com/Merchant2/me...egory_Code=GRT

ATP sells a gazillion variations of these basic garrett turbos with all sorts of hotside configurations.

The GT30 turbine wheel is significantly smaller than the P trim used on most 60-1/T04S turbos.

I'm actually referring to the GT3076r. If you're getting the 82mm compressor then your better off just getting a GT35r with whatever hotside you like.

Using the GT35 hotside (wheel and all) on a gt3076r you'll get more flow and the option of a divided t4 flange which will respond better than a t3 with the same ar (so long as you're using a divided manifold).

https://www.rx7club.com/showthread.p...ighlight=gt35r
This car isn't using as much boost as your example, but its reaching 15lbs by 3600 and its not far off on power with another 40 to 50rwhp easily with more boost. It would spool even faster with a 76mm compressor and still have more to give than a 2871r.

How do you figure that using a bigger turbine on a smaller compressor wheel will give you a better responding turbo?

From my reading, I have found that, the bigger the compressor for a fixed rear turbine, the lower the boost threshold (rpm where positive pressure found), with maybe slightly more lag time, talking order 0.1-0.2seconds here.

When you increase the size of the rear turbine whilst keeping the size of the compressor the same, you have 'the same amount of exhaust gas' flowing through a bigger area, so you would expect boost to build later, with possibly more lag as well.

Before you say I have no real world experience blah blah I'm just trying to design a turbo that will meet requirements before I go out buying one. I'd prefer to not have to buy a few before I get it behaving how I want.

[EDIT]

The other problem when comparing these charts is, full boost does not really indicate that the turbocharger is actually giving the car its serious power boost yet. You can say that the GT3582R is on full boost of 15psi @3600rpm, and that the GT2871R is making 17psi by 4000rpm, but by the nature of the smaller turbo, the GT28 car should definitely be making more power at that rpm, and accelerating much faster. If this wasn't the case, everyone would just be using ridiculous turbos.

The GT28 car might lurch forward from 2000rpm for all we know, and the GT35 car might need until 4500rpm to lurch....

Where have you found solid info on the 60-1 front wheel, and the p-trim, I'd love to be able to compare them.

http://www.turbocharged.com/catalog/comp_wheels.html

http://www.turbocharged.com/catalog/twheel.html

THANKS for that!

I wanted to track down a couple of threads before posting again but you can't use "t3" at all any more when searching. They're lost to me now.:cursing:

I did manage to find this one again.
https://www.rx7club.com/showthread.p...hlight=gt3582r

I hope its at least a little help full.

quattro

so he made 400+rwhp with a T3 flanged turbo that had a 0.7 rear A/R on it. Same compressor as the GT3582R/GT3082R.

See it is possible, and he said it was very responsive!

I never said it wasn't possible. It's just that you are pretty much required to run an open wastegate and most of us don't due to the shear noise or the extra attention from police.

Also, while it is a t3, its also the same turbine as a gt35r.

A couple of things you can do (or really don't) if this is for an engine build:
1) Don't port the exhaust. Chamfer the top and sides, and put a small radius (6-7mm) on the bottom. Nothing more.
2) Leave the primaries alone.

If you fabbing your own manifold, use 51mm OD tubing.

The engine is built and run in, has had 2 different intakes on it, and is finally turbocharged using a standard S5 unit at the moment. Its still non-intercooled, as I'm moving the battery, but have all the pipework. I want to get some WI on it, and finish the 3" exhaust with GOOD (EXPENSIVE$$$!!!) mufflers. So its a bit off.

The primary ports have been touched, but have very little extra size. The exhaust ports have also been touched a little more, but as you said, my porter also said that porting will not reduce lag in fact increase it, so he kept it all mild. One thing sticks to my mind 3+? years later when I asked him whether porting effected spool, he said, the only thing that really changes spool is the size of the rear wheel in your turbo. I now understand this so much later in time.

Also remember my engine is a 9.4:1 compression tall port 12A, using a downdraft IDA intake with 50mm throttle bodies.

wooow! grave diggin but this is really good info!

Interesting discussion full of misinformation:blush:

Its easy to jump on bandwagon that evereone does it in this way and anything smaller will cause annihilation of human race:lol: Then its no wonder that all usual 13B setups have no low-end and midrange...

Just for updating this information and bringing some info for reference: I recently went through that thread and found out, that ultimately he went with full GT2871R core, turbine housing included. It gave him even better spool up AND better top-end. GT turbine aero is much better than old stuff. Peak power also went up, to 200rwkw - airflow limited, not turbine limited.

Another nice example is that AutoX FD in dyno section: GT35 hotside in 0.63 A/R housing and Precision 55mm compressor - 250 rwhp by 3800 rpms and 360 rwhp by 5900 - on dyno dynamics, easily over 400 rwhp on dynojet...

There is no need for guessing and repeating same old BS. Just brief glance over turbine maps reveals that GT35 hotside in 0.63 A/R flows much less than GT30 in 1.06 A/R. And still it produced very solid power with mountains of torque. Even with 0.82 A/R it basically flows less than GT30 in 1.06 A/R apart from slight advantage at high expansion ratio.

Boost control is another thing and of course, in case of these setups, gate(s) and whole manifold setup must be designed with fact, that as much as half of exhaust flow must be wastegated - not only to have proper control of shaft speed but also to relieve heat load - especially in top end.

So if anyone wants to have super responsive setup around 400 HP, then I´m pretty sure that GT3076R or GTX3071-76R would do it no problem.

yeah i'm noticing that all the info is getting a few years old now. i'm curious to see a turbo with stock spool times that reach around 350-400hp range without overspooling or creating a ton of extra heat.

You are looking for a 60 trim To4E, ball bearing with a .84, tubular manifold, and a big exhaust system.

The other smaller stuff will create a lot of exhaust backpressure, and egts will skyrocket in the higher rpms. I have done it before, if I remember correctly was near 1800 deg F past 6200rpms. Was 400rwhp @ 16.5psi on something extremely close to a GT3076R..

Can´t arque with that!:icon_tup:

I totally forgot about turbine exducer size itself:blush: Its always better to have big wheel in small housing than vica versa.

I have changed my views on turbos since those 2-3-4 years ago. I now believe in critical sizing for a job. I would never use a GT3082R or a GT3076R, nor even a GT3071R. I would probably use a GTX3071R if I had more money than sense, but I would never put a single entry turbine on a rotary or nearly any piston engine either.


With a GT28 he is certainly turbine flow limited, there is no question whatsoever.

If you take a good look at the dyno sheets and also other information available power actually goes down when you change from a divided 1.0 exhaust housing to a single entry 0.63 exhaust housing. Unfortunately there is no such thing as a golden bullet for all the problems of the engineering world. Solid design cannot be replaced. Every day manager and marketing and sales types try to give their engineers golden bullets to throw at problems like 'magic gt aero' when really what they need to do a better job is better equipment for testing or more information about the problem.

GT aero is mostly marketing (unless you have an engine that requires 30psi to go anywhere, and has no exhaust energy)