Hi all from Poland,
I've got a 99' rx7 fd that im finishing building right now. My engine is freshly rebuilt stockport.
I decided to go single mostly for simplicity, reliablity and sound reasons. Power level similar or slightly higher than stock twins is all I really need and want - I daily my fd.

For a few months now I've been researching the best turbo for my application. Initially the turbo that I fell in love with because of this forum was EFR 7670 1.05AR twinscroll - unfortunately borgwarners are veeery expensive in Poland.
Having read countless amounts of comments and threads here, I've made my decision on PSR 5455g (Pulsar equivalent to G30-660, as these are very common and cheap in Poland). Based on what I read it should be Garret's response to the EFR7670.

My main question is now about A/R, should I go with the biggest one that Pulsar offers - 0.85 T4 twinscroll or maybe the Garret one - 1.06 T4 twinscroll?
Im leaning towards the 0.85 as I've read some comments by @TeamRX8 suggesting that this would be the closest match to the EFR7670 1.05 AR.

My biggest concern now is EMAP - I plan to run this turbo on boost around 11-13psi, I've got 3.5inch DP into 3inch straight exhaust and oldschool Greddy TRUST 50mm wastegate dumped. I also got HKS intercooler kit with koyo radiator.
Looking forward to your inputs - maybe someone ran this exact turbo on FD? Thank you so much in advance.

 

Hello Poland!
welcome to the forum.
your contemplated turbo is a good match for your objectives. i am aware of Pulsar but have no knowledge as to their end product. i am firmly in the Garrett camp so if the Pulsar is a properly executed copy of the Garrett product you will be a happy guy.

as to the hotside. i think the .85 T4 is the match for you. i did a comparison of hotsides w a BW SX_E 62 in 2018. .91 V 1.0. while the 1.0 EGT was 40 F less and 3 pounds less EMAP, the .91 made really good power w no fall off thru 8800. i was impressed... also a couple of hundred earlier spool.

of course we all know that the A/R is simply a relationship metric rather than an absolute so a 1.0 Borg Warner A/R and a Garrett, or Pulsar, could be different. if the comp map is similar to the Garrett you will be probably running no more than 57 pounds per minute. 427 rwhp..

good luck

 

Thanks so much for your reply and insights Howard!

 

Brettus does ~420 whp with G30-660 and a T3 open scroll 1.01 AR on an RX8 Renesis engine. Maybe 16 psig boost(?), can’t recall at the moment.

While I have both the 1.06 TS and 0.85 TS for back-back testing (with G30-770), ime you’ll be hard pressed to get that with the 0.85 TS without high octane/E85 fuel and cranking the boost higher. The response of the 0.85 TS will definitely be better for a street application with pump gas and boost level that you indicated.
.

 

I will be perfectly satisfied with near stock level power, not trying to chase ~400whp. I have 1300IDX secondaries and walbro255 - just trying to keep it lowkey and reliable. 0.85 TS will not choke on my boost target and my EGTs will not be super high right? I have 3.5dp into 3inch straightpiped exhaust

 

If going for a pulsar turbo because you're comparing it to its G series counterpart. You need to go one size up as the pulsars don't flow anywhere near their g series counterpart. They're worse by 10-12% on average not to mention rotary heat. Good luck with the pulsar turbo. Hopefully it does well.

 

Oh thats good to know, thought they would flow pretty much the same. Issue is that for Pulsar the biggest T4 divided housing is .85...
Would going with PSR5455g (g30-660) but with garret turbine housing (1.06 T4 div) make the most sense? I just want this thing to be reliable and avoid high EGTs.

 

Sorry but that's just straight up wrong.


There are numerous workshops in Australia and elsewhere pumping out E85 flex fuel or methanol tune/build packages on everything from Barra and LS builds to GR YARIS and full billet rotary packages and they dyno every car and offer customers Pulsar or Garrett at their discretion. Half the components are probably coming out of the same factory in China. Where Garrett turbos are made.

I'd also love to understand how the name on the compressor cover casting changes the physics or air flow, speed of sound at fixed conditions, density and flow through an orifice of exactly the same dimensions.

 

Any shop claiming Pulsar and G series are the exact same with no drawbacks using the cheaper pulsar option...i'd like to see some real world data. Gavbey uses pulsar turbos on his vr6 swap rx7 FD and when I asked him if I should use it on a 13b...his answer was one word, No! (because It wont survive rotary heat). You get what you pay for....they are a third of the G series price tag and there are drawbacks of using them.

Also Pulsar and G Series are not made in the same factory in China or to the same standards. It's a commonly debated rumor in the turbo world but its very misleading! It's the same as claiming a fake rolex is the same as its genuine counterpart!

• Garrett G Series = OEM-grade, tested for hundreds of thousands of cycles. High-end, precision-built, tested turbo by the community. Garrett uses proprietary, ISO-certified facilities with OEM-level quality control. Garrett uses aerospace-grade alloys (e.g., Mar-M247, TiAl). Garrett has tighter tolerances, better balancing, and validated testing. They provide compressor and turbine flow maps. Garrett is built for long-term abuse (track, racing); Most if not all World time attack cars are using G series.
• Pulsar = good replica for the money, but not engineered or validated to the same level. Pulsar is made in independent factories with lower QC standards. Pulsar uses cheaper alternatives like standard Inconel or cast aluminum. Pulsar replicates the Garrett design but lacks the same engineering refinement. Pulsar may look similar but flows less, spools slower, and handles less heat. Pulsar is better suited for budget street builds.

That said, Pulsar turbos still offer great value for street builds and moderate performance goals but don’t let marketing myths mislead you into thinking they’re “the same with a different logo.” Pulsar is a cost-effective replica but it's — not a true equal to Garrett in quality, performance, or reliability.

 

Gav is a great guy and very resourceful, I offered some advice when he was playing with compound stuff. He is a tradesman not a metalurgist however.

Garrett only use MarM on smaller turbos and didn't offer it on most general aftermarket until recently (a handful of rally anti-lag tolerant turbine, intake restrictor "compatible" low trim compressor jobs TR30R[?] and a few general market "RS" models), so for the last 45 years people have been using inconel turbines on rotaries, including on leaded race fuels that don't cool like alcohol fuels or water injection mixes before ethanol was a thing and people didn't have fuel system capacity or want dual fuel street/strip turbo cars. I can't remember what frame size the cut off is but most high power rotary users are above it.

Do you have any lab results on samples of turbine wheels/shaft or roller bearings or even photos or footage of a handheld xray spectral analyser demonstrating significant difference in the alloying of the critical components? I bet you don't. If you want to make the "chinesium" call, hire one and do it, send some bits to the lab.

So for most of us it's inconnel turbine in a stainless housing vs inconel turbine in a stainless housing. If they weren't inconnel there would be failed turbos on every rotary or high output piston motor.

Garrett isn't some bastion of moralistic right. They chose to outsource both design and production for profit then trippled the price of turbos in 15 years anyway. Here's a hint, if extremely low volume suppliers like Xona and Turbosmart can bring turbos at a similar price point to OEM heavy industry and auto suppliers whose engineering teams, equipment and software licenses are subsidised by their OEM work, what's going on?



I assume some of that was cut and paste from the probability plaigerism machine?

L.O.L. at Titanium aluminide if you are worried about temperatures or pushing turbos to their limits. Titanium aluminide is why people started having to fit EGT and shaft speed sensors to every build not to grenade turbines on BW EFR 9180s.

The wrong brand.


This is why people need to realise a large language model doesn't compensate for high school physics & chemistry, an engineering degree (hons) and experience working in the physical metrology branch of a national measurement institute or laboratory.

PSA: LLMs are designed to respond with confident tone and to be agreeable to and reinforce arguments put forward in your prompts regardless of any attachment to reality. If using them for technical automotive or engineering applications you want to be pretty sure the source materials are limited to quality manufacturers datasheets, manuals or similar materials, published peer reviewed academic papers or forums with very technically competent in field professionals like Eng-tips. The performance aftermarket is full of forum posts from absolute window lickers and scam businesses spruiking their version of products or trying to shitcan their competitors. I was actually discussing this problem with a friend at the pub on Saturday, he is global sustainability manager for a steel company having formerly been engineering manager. The "business school" born to rule US managers use LLMs instead of internal or hard industry data and have to be corrected because they don't understand its all sourced from a now poisoned internet.


I will be clear on one thing, if I was contracting build to a Chinese manufacturer for longwall roof supports or hydraulic pumpsets (I'd try to source from Europe myself) the contracts would have independent 3rd party material testing before exchange but the cases of **** steel being supplied are self evident in short order as you get cracking and failure in service at very short life. There are dodgy suppliers in every industry but the irony is most of the problems are driven by greedy business owners based in the US, UK, AUS etc intentionally try to scam local consumers with **** products. Like Amazon cloning products as soon as they reach a turnover threshold on their platform.


If you are running a 24 hour race, an endurance circuit series or Targa series with big Garrett stickers on the car and expect a free replacement from the nearest dealer on failure, sure go nuts. Duty cycle and thermal load on a street car compared to an endurance circuit racer or boat racer is laughable. Both of which are nothing compared heavy offroad earthmoving plant or trains, generators and pumps.

The reality is suppliers will often bork at any self installed turbo warranty claim unless the person has a trade licence and a business account. I know there was a decent number of very short life Garrett failures here a couple of years ago, with a lot of "user error EAD" responses to warranty claims. I think Turbosmart are the only ones touting an unconditional warranty.


Again, can you please explain how compressor and turbine sets with the same geometry flow 10% more with Garrett cast on the compressor cover?

Are you saying an additional 8+ kilowatts of heat is being absorbed by the inferior material turbines and shafts? Why aren't people seeing significantly higher EMP and EGTs at the same target lambda at high for size power levels?

Garrett should start selling +10% flow for size intake restrictor plates for restrictor racing classes. They would chalk up a lot of wins.

 

Regardless of whether the above discussion is proven or not...

90% Turbo for 35% cost? SOLD! 😁😁

 

Reliability will come down to the tune and quality of supporting mods. Reading your original post you only want to run 11-13psi....so you should be fine with the 660 if you really want the smallest turbo for response.

However, if you want my advice go for the T4 divided 6262 so you have future proofed yourself. It should be able to run low boost you want easily and you'll have a good powerband with decent mpgs on cruise and motorways.

 

I'd also love to understand how the name on the compressor cover casting changes the physics or air flow, speed of sound at fixed conditions, density and flow through

So, the poster was saying go a size larger on Pulsar exhaust housing to get same flow as G series.

Makes sense.
Garrett says they used Mar M for exhaust wheel so they could form a thinner higher flowing exhaust wheel.

So either Pulsar is replicating G series exhaust wheel aero in Inconel and it flows just as well, just isnt reliable

Or

Pulsar uses a traditional robust Inconel exhaust wheel that doesnt flow as well or handle the rpm of the lighter, thinner G series Mar M exhaust wheel.

I havent seen all these efr failures. Does BW pay people off not to post about them?

 

Yeah for sure, I just want to be cautious about the hotside so it doesn't choke the motor out. I'm 100% decided on the Pulsar g30-660 copy, now I just need to figure out .85 vs 1.06...
Based on many discussions I read here and mostly @TeamRX8 's comments, I understand that .85 TS on g30 should be comparable to EFR's 7670 1.05 TS in terms of flow... Can anyone confirm this?

 

Based on many discussions I read here and mostly @TeamRX8 's comments, I understand that .85 TS on g30 should be comparable to EFR's 7670 1.05 TS in terms of flow... Can anyone confirm this?

Whats it matter since you arent buying either of those turbos?

 

Are you using pulsar turbos on builds yourself and can you confirm they flow the exact same as G series or the respective turbos they are copying with real world data?

Pulsar also copy borg warner and precision turbos. End of the day you dont have to buy Garrett/Borg/Precision turbos to make power. Buy the Pulsar if you believe its the same thing as a G series, Borgs or Precision. I dont understand why we are wasting time comparing premium turbos to their cheaper copy knock off?!

Its the same age old debate...Rays TE37s are a rip off because they're soo expensive and cheaper knock offs are just as good because they will get you from point A to point B.

Do what your budget allows as you get what you pay for and premium performance is not cheap.

 

No one can confirm as pulsar dont have compressor or turbine flow data because their wheels are a copy and not validated for flow. You're just gonna have to try it and hope for the best. I have data from a G30 770 at 14.5psi running around 420hp on base pump fuel 99 ron. It runs a consistent 100-200km/h in around 8.4s. If you get anywhere near this number in the real world with consistency and reliability than you know your setup is performing well. In fairness, if you get anywhere near low 9s range you should be happy.

 

I mean I can get pulsar "g30-660" with either .85 pulsar exhaust housing (biggest they offer T4 TS) or with garrett 1.06 TS exhaust housing (I would buy the PSR turbo without their housing and buy one from garret separately)

 

ive done a g42-1200 pulsar vs Garrett

spool and power was identical as far as I could see, the pulsars seem more sensitive to oil return size and oil feed pressure, I had a few fail when I got this part wrong, Garrett seem to have no issues with a AN8 return and normal rotary oil pressure where as the pulsar seized up after a mont of usage, had to do AN10 return and OPR40 and that seemed to do the trick to keep it alive.

thats my 2 cents on pulsar.

 

You made a very specific claim about flow rates without evidence (an entire frame size apparently), you posted an entirely incorrect statement about turbine material. If you make the first claim the burden of proof is on you. This is like religious morons pretending the burden of proof is on everyone else to demonstrate Xenu doesn't exist.


If you go to the bank asking for a business loan do you make unfounded comments stating you can service the loan and then demand they prove the opposite doesn't work like that.

 

And again anything bigger than 35 in Garrett is inconnel anyway. All the turbines I have seen including a drop in billet front 9 blade rear 35r replacement core are definitely high flow not the old style thick blade turbines. You don't really see people melting BW, Holset or Garrett inconel turbines unless they are running massive anti-lag or have other failures regardless.

 

Very interesting and durability seems to be a concern. Will you consider swapping out G series and Precision's for the cheaper pulsar copies if they flow and spool the same?

 

Not yet, Still early days for me seeing as I definitely had a fair few fail and when we replaced them with Garretts with nothing else changed, the Garrett's didn't fail. Since then as I mentioned we made some changes to the oil feed and return configuration and it seems they are not failing anymore. Time will tell