Lithium

Yeah very fair, and still relatively untested on RBs - though initial results from the RB30 ECR33 in Brisbane look pretty impressive. G40 looks like it should be a pretty solid choice, a few people have used them too.

On the compressor side it looks like the best, if your head setup will support doing 100-110lb/min at 30psi-ish boost. The G45-1350 compressor looks ideally better if you need closer to 40psi for it, given both the G40 1150 and G42 1200 look like they'll be around the 100lb/min mark at 35psi and dropping from there. Bear in mind the turbine sides are all different between those three turbos, so that COULD be an influencing factor for how they all perform in the real world as well. Not sure if you've made a conscious decision to only look at Garrett or not, but at least on paper the XRE7169S matches or beats those other three at everything from 30psi up and just going from wheel size alone likely to be at least as responsive as the G40 1150 and seem to behave closer to G42s in terms of turbine flow.

Haha. I wouldn't say I am either but I've definitely been around it plenty. I'm guessing you know the dial in is basically to make a handicap to level the playing field between racers. The car with the slower dial in goes first and in theory if they run their dial in time and the faster car also does then they cross the finish time if they also have exactly the same reaction time - if you go faster than the dial in them you lose, but if you are too slow there's a good chance the other person will get to the finish line first. I'm normally supporting other cars but they were all pretty dialled and were egging me on to race as well, here's one of the cars I tune (Starlet) which ran within like 1 hundredth of its dial in through the competition: https://www.youtube.com/watch?v=inEBu-d9Gn4&t=69s

Traction wasn't bad, l couldn't give it everything off the line but was able to go WOT about half a second after rolling - good for NZ drag strips. Like one run I did a 1.96 60ft and pretty sure I was on for a 12.4 but lifted early as I was on a 12.5 dial in, and still won haha

Took the dirty BMW to an actual drag meet so I could do a legit full pass on a sticky enough track and had a quiet goal to try and beat my PB in the old R33 GTS25t The time to beat: R33 on stock RB25, Internal gate GT3076R on stock manifold tuned to about 17psi on BP98 and running on drag tyres: F20 M135i with intake, dump pipe and MHD OTS Stage 1 tune on street tyres - didn't even drop the tyre pressure: Kinda similar, and kinda way different

A lot of what you said there are fair observations and part of why I made that list, to make some of these things (like no advantage between the GSeries and GSeries II at PR2.4 in a lot of cases) however I'm not fully convinced by other comments. One thing to bare in mind is that compressor flow maps are talking about MASS flow, in terms of the compressor side you shouldn't end up running more or less airflow vs another compressor map for the same advertised flow if all external environmental conditions are equivalent if the compressor efficiency is lower as that advertised mass flow takes that into consideration. Once the intercooler becomes involved the in-plenum air temperature shouldn't be that different, either... the main thing that is likely to affect the end power is the final exhaust manifold pressure - which *WILL* go up when you run out of compressor efficiency when you run off the map earlier on the original G-Series versus G-Series II as you need to keep the gate shut to achieve similar airflow. Also, how do you figure response based off surge line? I've seen people claim that as an absolute fact before but am pretty sure I've seen compressors with worse surge lines actually "stand up" faster (and ironically be more likely to surge), I'm not super convinced - it's really a thing we won't easily be able to determine until people start using them. There are some things on the maps that actually make me wonder if there is a chance that they may respond no worse... if not BETTER?! which brings me to your next point... Why G2 have lower max rpm? Really good question and I've been wondering about this too. The maximum speed *AND* the compressor maps both look like what I'd normally expect if Garrett had extended the exducers out, but they claim the same inducer and exducer size for the whole range. If you compare the speed lines between any G and G2 version the G2 speed lines support higher flow for the same compressor speed, kinda giving a pretty clear "better at pumping more air for the same speed" impression. Presumably the exducer includes any extended tip design instead of just the backplate, but nonetheless I'd love to see good pics/measurements of the G2 compressors as everything kinda points to something different about the exducer - specifically that it must be further out from the centerline, which means a lower rpm for the same max tip speed and often also results in higher pressure ratio efficiency, narrower maps, and often actually can result in better spool vs a smaller exducer for the same inducer size... no doubt partly due to the above phenomenon of needing less turbine speed to achieve the same airflow when using a smaller trim. Not sure if this is just camera angle or what, but this kinda looks interesting on the G35 990 compressor tips: Very interested to see what happens when people start testing these, and if we start getting more details about what's different.

No worries. They have a section on their website with some RR options listed, no doubt you can find out more by EMailing as well tho Reverse Rotation Motorsport Turbochargers – Xona Rotor

Updated with the latest <68mm Xona Rotor turbos. The two XRA options are on paper some of the compressor performance I've seen

I've edited the original post to include include Turbosmart turbos - the first list is "entry level", or up to 68mm. The second is "for those who like to party" and starts at 62mm.

Yeah I did, was a good one Also pretty sure Xona do mirror options

90lb/min @ 20psi is wonderful, not so much of a problem with the G35-1050's compressor efficiency (aside from how bad they roll back at higher pressure ratios). The issue is more to do with the turbine's flow, which is why I'm not sold on going an even higher flowing compressor with the same turbine. I'd say go back over Motive DVD's testing of the G35 1050 and Hawkins's comments regarding exhaust back pressure issues with it, I'd need to go back but I have in my head he went to the biggest hotside and ended up sacrificing a lot of spool (so it ended up behaving like a bigger turbo) and still had EMAP issues. I've heard various other experiences along the lines of that. At this stage at least I rate all I've seen about Xonas (for transparency I've not used one directly, but I have spoke plenty with people who have) to have low exhaust restriction for the response they offer for any given setup - basically they allow the engine to breathe, which is good for the engine and makes making power a lot easier. You arguably don't have to even push quite the same amount of airflow through an engine to make the same power if you don't have the bum plugged up with exhaust gas struggling to escape the engine due to an underflowing turbine. In terms of reliability, to be fair I've had great luck with Garrett turbos as well - my GT3076R lasted forever, then I sold it and the next owner had no issues, then that car got sold and it was still going strong last I ever heard about it. The trick is with the old GT-series turbos the compressors etc were no way near as efficient as what we have these days, it was almost hard to push them into severe overspeed situations without having a boost leak or something - and that is what often starts the failure situation. In terms of your G35 I'm pretty sure you're running yours within sensible limits, something people with Xonas and Precision turbos aren't often so inclined to do. The "compressor maps" are "Joe blogs ran 45psi through his 6466 so I can do the same" and built their setup to send it to the moon. I've seen EMAP and compressor speed data where people have actually set that stuff up on Precisions and Xonas which have been run hard and the comp speed numbers are very very exciting at times - like I've seen 76mm Precisions run at rpm that you ideally shouldn't run a G35 1050 lol. I know people who have run G-series Garretts hard and hard a failure, then replaced them with Pulsar turbos as a cheap "get it going" stop gap with the intent of doing a proper upgrade when THAT fails... and are still running the same thing. Like anything, ymmv and it's not always to do with the quality or trustworthiness of said product. I've been provided with a bunch of compressor maps for Turbosmart turbos and will update my list based off that, they could prove to interesting reading and an interesting alternative as well.

You'll find this link is probably more useful Performance Turbochargers - Garrett - G GT GTX GTW Series Turbo TBG G35 1150 map may not even get added to my list depending on how it looks, the G35 1050 already is a mixed bag for making the numbers you would expect from the compressor map due to mismatch - I don't know how another 10lb/min of compressor flow is going to make that any better. I've left out others for similar reasons as it's already getting quite big. In terms of Precision, provide me with legit compressor maps for them and I'll do my thing I'll add some more of the newer Xona Rotor options are they're pretty boss, I'd take a 68mm Xona over a G35 "1150" any day of the week - or Precision for that matter.

BTW, the reason I came in here to "update" this list was that the Garrett G Series II range have been released and I've updated the list with their flow details if you're curious to check how they fit with previous Garretts and other brands The G-Series II G35 990 looks like a banger...

Hi all, I thought I'd put one of these references in here before but it seems I haven't - not sure how many people are actually using this place still but I feel like there are guys lurking about who might find this reference useful or interesting. A lot of the time people don't catch key details or even fully understand how compressor maps work - or don't even look at them and just go from heresay about deciding how different turbos may compare, but I've been putting together this table over the years as a quick reference to get a gauge of how certain compressors compare to cut down the time that can be wasted looking around aimlessly. * This relates purely to compressor flow, so won't necessarily reflect the outright capabilities of these turbos as the power potential also comes down to the turbine side. If you understand this, you should be able to use this 😃 * The inducer and exducer size listed are the mm of just the compressor wheel * The values under the "psi" headings are "lb/min airflow" and reflect the maximum airflow that compressor supports before it's efficiency dips under 65%, or it reaches it's maximum speed - whichever comes first. Any questions, or requests for other turbos which the compressor map is available for then let me know 🙂

Nice, is there a post with the new 4" dyno curve?