Drop in replacement for GT35r?
 

I've got a GT35r (T4 1.06 undivided) with a damaged turbine wheel due to a stray apex seal, and looking at options. I can get a new CHRA for ~900, but I'd like to have some kind of upgrade if possible. However, I don't have the money to replace my manifold or downpipe. I also don't really have the money for a new GTX supercore - my budget is in the ~1500 range. There used to be a couple hybrids (TDX61, etc), but it doesn't seem like those are around anymore with everyone moving to the EFRs. Am I missing anything? I assume I can still get a hybrid made by a turbo shop, but I think that would end up being a journal bearing turbo. I've also done some research and seen pretty good things about Kinugawa turbos, and they have a GTX3582 for ~$1200, but I'm still wary.

A little more background on the setup - FC w/ street ported 13BT (thicker casting, 2 extra dowels), FD HKS cast manifold (and necessary spacer to clear LIM), v-mount, megasquirt, 1050x / 2200 injectors, E85 capable. I'm looking for 350 for normal driving, with the ability to go up to ~450 if possible, but I know that's really stretching it for a GT35.

G35 900 or G35 1050 - instead wasting time rebuilding an old old turbo which might fail again...Bin it and start with the new tech imo if budget allows?

I'd love to get a G35, but they're at least 2500 from what I've seen. 1500 is already a major stretch right now, don't think I can swing 2500. I'm also not certain how the outlet would line up and if its the same flange, but I assume it would be.

it would be bit of a stretch to find a different turbo that will just 1 for 1 replace the garrett without having to adjust something. i would advise a borg warner SXE36x. budget friendly, comparable performance, and "high tech". for what youre looking to spend, you can swap an sxe in for that to include minor modifications to the downpipe if need be, swapping to the marmon flange if you get a back housing with that... then whatever mods to the charge pipe

If you do decide to go the Taiwan turbo route, have a look at Mamba (or Mambatech?) So the story goes, he founded Kinugawa, then sold the business or split or something, and now he's sells basically the same thing but its better. Basically has GTX geometry wheels for any turbo you can think of with any housing you can think of.
Ive had a Mamba turbo on my diesel* work rig for probably 150,000km and its still good.

* diesel, so its pretty much full boost all the time

I had a s366 in my old car. It was a beast up top, but hoping for better spool since I'm going to be driving it on the street most of the time.

The other problem is that I'm running this on an FC but with a FD manifold. Even with a spacer, it barely clears the intake manifold. I remember the s366 hot side being huge. I had a different FD manifold on that car and I had to shave the acv mounting casting off the intake manifold to clear it.

Another I've seen good things about is Pulsar. Feeling a little dirty talking about "knock-off" turbos, though.

Edit: does anyone have the exterior dimensions for the BW s36x turbos? I can find them for all of the garretts, but nothing on BW.
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Pulsar turbo offer both upgraded spec gt35 and G series and big name workshops are using them as their go to upgrade package turbos in Australia. Talking under $1000 US delivered for gtx / gen 2 stuff.

Is the manifold divided? If you want response you really should have divided manifold and turbine housing.

I've definitely been looking at them as well, but they don't have the larger a/r on some of them, such as the g35. They do on the g40-900, but it has the wrong exhaust flange.

I sent my old GT35R 1.06 hotside to force performance and they upgraded it to their billet compressor and modified the compressor housing.
It is now equivalent to their FP HTA GT3582R which spools faster and flows more sooner than the GTX3582R.

Garrett Gen 1 GTX3576R. Flows about the same as the old GT3582, but should spool a couple hundred rpm sooner and have better snappiness on/off throttle; lower rotational inertia and better efficiency. The compressor housing is the more compact T04E, but I imagine you can still keep the same compressor discharge pipe.

it should be noted that wrt mass flow rates that the Garrett G30 replaced the previous 35 line. The G30 1.06 div T4 housing flows adequate for 450 rotary whp.

A Renesis(!) RX8 on RX8Club reliably made 420 whp on a G30-660 1.01 open housing with E30 fuel. For 450 whp continuously the G30-770 would be a better choice.

The Garrett G35 1.06 div T4 housing peak flows 35 lb/min. It’d be lazy at the noted power levels. The copycat company offers a 0.85 div T4 housing though that should be a direct bolt-on for those who can’t stomach far east knockoff turbos. That would be better suited for the purpose, but the G35 is still otherwise quite a bit oversized flow wise for the intended power levels.

Note that said copycat company recently revised all their model numbers to not be so blatant about it. The G30-660 equivalent is now a PSR 5455G and for the G35-900 it’s PSR 6262G, etc.
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Lots of great info, everyone, thanks!

We got way deeper into the turbo selection discussion than I anticipated, so here's one item I left out to not derail the initial discussion - I'm running 9.4:1 rotors. I know the pros and cons, and this was done to maximize drivability in real-world scenarios (around town, and local country roads where I can't drive 100+) since that's where it will spend 95% of its time. However, I still want the ability to turn up the boost occasionally, which is why its built for e85 and I put in a v-mount. I'm also running goopy seals and IGN1A coils. My plan is to run at wastegate pressure (~9-10 PSI) with a somewhat conservative tune on 93, and have the boost ramp up with the ethanol content (yes, I have a flex sensor).

From what I've seen, you want to over-size the turbo a little since you can't just crank the boost way up so you want higher efficiency at a given pressure. Larger hot-sides also seem to be better since its lowers the EMAP. These seem to point away from the G30 and or GTX3576, at least based on my research. Also, I may be able to swing some extra money to get a real garret, its just going to take some advanced negotiation with the wife. The cost to move to a whole different turbo setup is still off the table, though.

Edit: In relation to the RX-8 using the G30, from what I have seen its a very different animal in terms of turbo selection due to the side exhaust ports vs our peripheral exhaust ports so they can get away with a smaller turbo, closer to a piston engine.

I suggested the GTX3576 assuming it would be significantly cheaper than the G-series, but that is not the case. I'm quite surprised to see the G30-770 is basically the same price. The G30-770 has a slightly lower flowing turbine housing which means it should spool faster than your old GT35. The G-series looks to have better turbine efficiency too which also helps spool and reduces back pressure. And the turbine housing is stainless steel which is more durable. The unknown is if the flanges are all in the same location between the G-series turbine housing and the old GT(X) series. If you go GTX3576R, you could reuse your old turbine housing. The G30-770 would be the all-around better performing and more durable turbo though. Personally, I'd save up the funding for the G-series assuming you would not need to modify your downpipe. Is there still the little drag strip in Temple? I went there once waaaay back in the day. No traction off the line at all,

Interesting that the g-series had a better hot side even when smaller. I guess it makes sense that a newer one is better, though. I skimmed the dimensions a couple days ago and it appears they are close enough to not cause problems.

Yes, we still have that strip! It's changed ownership a couple times, and the track prep is much better the last time I went. I spun off the line, but that was more due to my (lack of) skill. I still ran 12.3@122 despite a truly awful 60', I think it was 2.4 seconds.

Edit: found the slip, it was 2.3 seconds! I still beat a 392 Charger in a car I designed, built, and tuned myself - I was super proud of that.
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no, a Renesis can’t get away with a smaller hotside than an REW; it always comes down to the mass flow relative to power goal. It made 420 whp and both the compressor and turbine mass flow rates to achieve that are the same for both engines.

it’d be more accurate to say that some people don’t read flow maps well or do their homework much better. The Renesis doesn’t have the pulse energy plus the siamese center port means the pulses can’t be fully separated. This impacts response and low rpm boost potential. The 10:1 rotors and complete lack of intake-exhaust overlap get into other issues. None of it is related to what was claimed though.

I recognize that a true G-series was out of budget plus that was discussed prior as well, just trying to straighten out the usual bad info people post meaning well and just not knowing any better. Because as also discussed, the copy cat version costs a lot less if someone decides to go there.

I’m not a fan of that for the turbo itself (I have a Garrett G30-770 1.06 T4), but would consider a copycat turbine housing on a Garrett turbo given the limited selections so far on the smaller/lower hp sizes
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its smaller in diameter, but its deeper/taller. probably similar volume, but instead of short and fat its tall and skinny

or a and b got smaller, but c gets bigger
https://cimg2.ibsrv.net/gimg/www.rx7...e8b6303af4.jpg

stop focusing on the wrong numbers; mass flow is the primary focus


https://cimg9.ibsrv.net/gimg/www.rx7...716215c32.jpeg
GT35R Compressor Map


https://cimg0.ibsrv.net/gimg/www.rx7...4938b7e9d.jpeg
G30-660 Compressor Map


https://cimg1.ibsrv.net/gimg/www.rx7...855f6aa0b.jpeg
GT35R Turbine Map


https://cimg2.ibsrv.net/gimg/www.rx7...51c1c6925.jpeg
G30-660 Turbine Map



You’ve come a long way, baby … :suspect:
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now put this in your pipe and smoke on it for a while :suspect:


https://cimg0.ibsrv.net/gimg/www.rx7...2069aef0d.jpeg
G35-900 Turbine Map .


How many rotards would just throw on a 1.06 A/R for the same power level?

too many …
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i took a look at the current Garrett lineup, and i looked at it backwards, from the turbine. what i notice is that the turbine flows come in steps, and the steps stay the same.
for example the GT35, GTX35 and G30 turbines all flow about the same 32bs/min. the GT30, GTX30, GTW3476 and G25 all flow about the same. etc etc

the other thing is that for each turbine, you usually get a choice of compressors. the GT30 turbine wheel is available with about 3 different compressor wheels, so is the G30. etc

the turbine map doesn't make a lot of sense to me, but there is enough to compare between turbos.

more importantly, if you get a turbo with the same size turbine, you can just buy the super core and re-use your turbine housing, the GTX35's use the same turbine housing.
and lmao, its like $2500... why would you buy that?

because people are too dumb to realize that we should all go back to the year 2000 when turbocharging was at it’s peak development and will never be exceeded in any parameter from that time on?

is that what you’re trying to say?

the mass flow numbers only help you select for the output goal, but don’t define every detail beyond that peak goal. Understand that I’m mostly trying to help people to wrap their head around how to properly size up a turbo and not get caught out. It’s really not rocket science once you’re able break it down to mass flow values relative to power output level.

There’s a cost factor between a cast iron vs. stainless steel turbine housing. Have you priced an EFR8374 recently? Assuming it’s in stock on the shelf. Do you also think a flip phone from 15 years ago is better cost wise than the latest iPwn? If you’re on a budget like the OP is then yeah, compromises need to be made, but don’t be naive and think that 20 years of technology doesn’t have benefits.

Yet the improvements did come in increments; 35R, 35Gen1, 35Gen2, and then depending on your budget you don’t have to be all the way back in the dark ages maybe. You can also clearly see the financial advantage of sitting back let somebody else do all the development work and then just steal-copy their design i.e. Pulsar. I don’t agree with supporting such thievery to fulfill my own self-indulgence, but everyone chooses their own moral standard.

However, the current G30 is the former 35 model in a 30R package; smaller, lighter, and less MOI to spool up even with that high rotary exhaust temp capable Mar-M turbine impeller. Some people on here still aren’t grasping this despite me bellowing on about it for the last year or two. We haven’t even really seen anybody light one up on here properly yet. A few shades of it maybe by a youboob attention harlot once all the boobery and cluster antics are filtered out.

So it might be a bit premature to just write it off in such a manner. Likely people said the same about the 35R back in the day over some other dinosaur model no doubt. It only demonstrates that an internet forum is the equivalent of an insufferable cage full of parakeets in a pet store with them all trying to squawk over each other. That’s not directed at you, but is a general overall sentiment that does include myself as well.
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Generally your responses are a bit spicy for my taste. Even I must admit tho this is funny, and true.

~ GW

no, its more like i need to add a column for price. the improvements in the turbos may be pretty linear (from T04, to GT35, GTX35, GTX35 gen 2 to G30), but the pricing is not.
the GTX35 Gen 2 super core costs the same as the whole G30 turbo. so why wouldn't you buy the G30?

i find that kind of confusing, but like i guess Garrett wants you to buy the new stuff...

the GT35 got a better reception than some, but yeah some of those old threads are hilarious

Bah, I just noticed your housing is undivided. Garrett does not offer a native T4 flanged housing for the G30-G35 that is undivided. ATP Turbo offers a T4 flanged 0.82 A/R housing, but there's no telling what it flows. Another fun fact, even in the Garrett native housings for the GT(X)30-35s, the T3 and T4 flanged housings flow differently for the same stated A/R. The turbine maps Garrett shows are for the T3 flanged. That all said, G30 turbine in T4 0.82 A/R will have lower flow than your GT35 in T4 1.06 A/R.

https://www.atpturbo.com/mm5/merchan...Series-G30-770

Hy housing is undivided, but my manifold is divided.

you definitely want to buy a divided housing with whatever turbo you go with then, the low end response will benefit, but plan on some tuning adjustments for it

there was a new TDX62 supercore in the FS Marketplace that may still be available, I’d recommend a Garrett Gen1 1.01-1.06 divided T4 housing for it, with shipping and all you might come out in the $1200 range or so after purchasing both of those if still available

that would be a reasonable selection for your goals, Turbosource used to have TDX options but unless they have it in hand on the shelf then you might be waiting forever from them … 🤔

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