When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
"It seems to me that some people may still be in the previous mindset that all turbines are more or less created equal and all you have to do is compare the inducer/exducer sizing, but I came to recognize that the technology is changing and so how we view that has to change as well. That’s when it “clicked” for me, but there are still not many rotary results to fully back it up yet."
totally agree on both points. measuring size was helpful when tech was stagnant however much higher tech has impacted turbos. the ultimate driver for this investment, as always is the OE market. the specific driver is electric turbos, coming to a daily driver for you.
it will be interesting to see how the new crop of aftermarket turbos impacts rotaryland. i will be swapping my 9180 for a G30-1050 shortly.
in addition to dimension "D" another important factor is the quality of materials. better materials allows, especially on the compressor, the shrinkage of the hub and extension of the blades. Garrett, being acquired for a time by Honeywell, has had the resources of over 2000 engineers in the HON Aerospace Division. Garrett was then spun off but is a holding company and continues to have an extremely close relationship with HON. lots of CFD capacity on call.
hello new Garrett turbos .
Last edited by Howard Coleman; 12-07-21 at 02:58 PM.
it seems like those things coupled with the inducer and exducer diameters coming closer together, which then reduces the overall diameter; just the latest approach to skinning the cat, so to speak
but then also combined with the compressor changes as well, because overall efficiencies are up 15% - 30% over the GTX Gen2 depending on which specific size is being assessed. Which there were some big gains from Gen1 to Gen2 and some of the classic reference points on this forum are back from before then even
"It seems to me that some people may still be in the previous mindset that all turbines are more or less created equal and all you have to do is compare the inducer/exducer sizing, but I came to recognize that the technology is changing and so how we view that has to change as well. That’s when it “clicked” for me, but there are still not many rotary results to fully back it up yet." .
its sort of in reference to Blue T2's comment earlier, where he says the engine likes some expansion room (or maybe the exhaust needs to be big enough, something like that). it was then pointed out to me that these new turbos are longer, so the size may not change much. they shape will, not sure the engine cares about shapes, most of us have seen what it can do to a muffler....
Here’s a G30 1.06 divided T4 from when it first came out to check for fitment in an extremely short low mount configuration in an RX8 chassis. Now trying to finalize between the -770 or -900 compressor; best possible response vs best possible efficiency. Decisions, decisions … 🤔
I have some updates with the 12 psi /low boost performance of the G35-1050. I've done 25 100-200kph runs on this turbo and it is most definitely faster in the real world compared to my older T04Z at 12 psi boost. That being said as most have already mentioned I should have gone for the T4 Divided 1.06 housing. I have lost 1000rpm spool over my older Turbo as a direct back to back comparison. However, that spool loss being a factual and objective measure in terms of my data collection hasn't actually made the car slower in the 100-200kph dragy gps runs, infact the opposite I've gained performance.
I used the Dragy GPS device to measure the cars real world performance with the old turbo (TO4Z) v new turbo (G35 1050) to get a baseline of how just swapping out a turbo would impact the performance in the real world...not just looking at dyno data/turbo spool. In my opinion dyno numbers dont mean much without the real world performance/data as you can easily mess with dyno numbers to show what ever figures you are shooting for. The hard truth of 100-200kph acceleration with the Dragy GPS device is that often times truth can be a bitter pill to swallow / fascinating to behold if the data confirms it. I really hope more RX7 owners invest in a Dragy GPS and post their 100-200kph acceleration runs as well along side their dyno numbers.
Approx 400hp on the G35 1050 at 12 psi.
The conditions were great with a 20*C AIT's, the car performed flawlessly and the run felt effortless. I'll add all runs were done with a full tank of fuel or near full fuel weight. My FD is full-fat weighing in at 1,315 kgs with driver inc full wet weight. Although a slight negative slope, dragy GPS deemed it a valid run and that's good enough for me. I suspect if the gradient was level...I would expect to be in the low 8s range (based on the data I have and also looking at runs I did going up slopes etc..)
Final few runs to wrap up the 12psi map. This time 10*C hotter (30-35*C) AIT temps compared to my PB run and as I suspected low 8s runs from 100-200kph when the slope is bit more level.
My PB with the 12psi 400hp TO4Z previously was 9.29s and some of the most optimized runs in the TO4Z were done around the 8.95s-9.29s range on a level slope. So in my isolated testing i'm seeing the G35-1050 consistently perform the 100-200kph in the 7.85s to 8.20s range depending on the conditions and the speed of my shifts. Overall, I personally dont miss the loss of turbo spool and worst case if I really want to optimise powerband I could always get a T4 housing with the 1.06 ar.
Next step is to get to 14.5 psi and test to see if there are any worthwhile performance gains to be had over the 12psi boost setting. If it drops me into the mid to high 7s range consistently for 100-200kph, than it may become my new low boost setting without the need for wmi etc. That being said, in the wet 12psi 3rd and 4th are scary but in dry conditions I dont mind going upto 1 bar provided the gains are worthwhile.
Thanks for sharing decent data, I'm surprised at the boost threshold difference, I would have thought even with the larger AR V band housing that you wouldn't be giving much up on the smaller turbo. I guess it just reinforces the benefits of twin scroll housings on 13bs.
single scroll V-band with 1.21 A/R must come on like the afterburners kicking in around 5500 or so I’d imagine, and likely increase that affect with higher boost …
Thanks for sharing decent data, I'm surprised at the boost threshold difference, I would have thought even with the larger AR V band housing that you wouldn't be giving much up on the smaller turbo. I guess it just reinforces the benefits of twin scroll housings on 13bs.
Hey no worries. Sharing data with real world performance in 2022 is almost a no brainer. We have all the tools now to share good reliable data. Its a real shame more of us are not sharing real world 100-200kph data via dragy gps.
I will get around to doing some back to back testing and validate the two housings via dragy gps performance. The setup that is consistently faster from 100-200kph acceleration will be way to go (for me anyways). Its a brutal test of acceleration/traction and building a safe optimized map leading to an overall reliable package instead of untested dyno queens that may / may not survive a WOT 100-200kph run from 3rd to 5th gear!
Honestly speaking I am as surprised as anyone, lost 1k rpm of boost response I was certain I would have the overall slower package from 100-200kph...but the results confirmed the opposite. This to me says theory and great data can only get you so far. Real world testing is the key factor missing from a lot of RX7 tuning/data points. We can no longer take a guess by just looking at data/theory, we also need to validate by testing real world performance.
single scroll V-band with 1.21 A/R must come on like the afterburners kicking in around 5500 or so I’d imagine, and likely increase that affect with higher boost …
It really is incredible. I cant wait to start testing at 20-25psi and see what numbers i get.
Had some time to up boost to 14 psi. The 100-200kph felt soo much better. Consistently in 7.6s range now! I need to get my go pro out and start recording these runs.
G42
Hello guys, I'm building a 13brew, the goal is 600+,hp, for Street use i'm thinking of putting a g42 1200 v band 1.01ar turbo, it's a good choice? what kind rpm of spool i will I have with this turbo?Im working low boost 14psi and high boost 25psi with methanol
G42
Hello guys, I'm building a 13brew, the goal is 600+,hp, for Street use i'm thinking of putting a g42 1200 v band 1.01ar turbo, it's a good choice? what kind rpm of spool i will I have with this turbo?Im working low boost 14psi and high boost 25psi with methanol
I'm not an expert but I was told by a few experienced tuners (no names mentioned). A G35 1050, G42 1200 or a G45 at 14psi...providing there are no restrictions will make the same power (I'd take that with a pinch of salt. If that trail of thought is correct?! At 14psi on a G42 1200 your 100-200kph at 14psi will be similar to what I've posted above with the G35 1050. Ideally I would have thought at 14psi the G42 will be able to move more air than a G35 1050 and therefore you should make more power and also a faster 100-200kph. However, you will have to test this.
The difference with the G42 1200 will be at 25psi to 35psi, where the G35 1050 will start to max out due to exhaust flow.
Turbo spool will be dependent on your setup, I would imagine a large bridge port or a semi pp running e85 will improve spool.
On a street port like mine running pump fuel with a Vband 1.21 ar the G35 1050 makes 14psi at 4400rpm and 20/25 psi at 5000rpm. Id wager the G42 will have 500rpm of additional lag. However, if you run a T4 you may gain more response.
Got up to 16psi. This was not the best run. Loads of wheel spin into 4th....followed by a lot hesitation whether or not to abort the run but decided to stay in the run which no doubt cost me a bit of time.
However, the negative gradient makes up for the granny shift into 4th followed by the wheel spin, followed by a split second decision to stay in the run. If it was fully flat...it would be fairly close to this time. That being said its a valid run so..ill take it .
I've been going through some data I collected and to summarise
In summary, going up 4 psi I've gained almost 1s of performance. This is an insane real world performance gain by simply increasing the boost. So far its worth increasing the boost as the real world gains are being confirmed by the 100-200kph runs. I'll keep going until I max out the turbo or the gains stop.
The goal is to get to 20psi and see if the gains are still worthwhile etc..
A 4 barrel on a street port would move your peak power over 9000rpm. So yes it will make a heap more power.
G35-1050 can move a lot of air.
A g35-1050 on an extend port on E85 with stock intakes will need around 30psi to make 600
Same turbo , same engine, E85 with a 4 barrel will do it on around 21-22psi.
If your doing pump fuel with water injection youll need more boost to make the power with either combo.
After reading this i'm very tempted/ certain i want to go 4 barrel to improve the peak power and also make more power at lower boost. These two key point for me are worth it.
Say if i can make 20psi by 5k rpm, does that mean ill have a much better powerband than with the stock inlet? for eg with a barrel i can come on 20pi at 5krpm but instead of the power and torque falling away after 7000rpm...it will hold till over 9krpm? so in effect i can keep what i have from 5k rpm to 7krpm but also unlock a further 2k rpm top end but also make more power with less boost?
alternative is a Xcessive LIM (hard to find currently) with custom plenum UIM right on top of it. The long runner theory is highly overrated for the current technology fast-responding turbos. Thats more or less what’s achieved with the 4 bbl setup though it’ll have slightly shorter runners as seen below, but not recognized on here because most members are stuck in their “this is the way we always do it and can’t think outside the box” rut. Because all that extra pipe length relative to runner ID flow size adds friction and pressure differential that has to be overcome:
alternative is a Xcessive LIM (hard to find currently) with custom plenum UIM right on top of it. The long runner theory is highly overrated for the current technology fast-responding turbos. Thats more or less what’s achieved with the 4 bbl setup though it’ll have slightly shorter runners as seen below, but not recognized on here because most members are stuck in their “this is the way we always do it and can’t think outside the box” rut. Because all that extra pipe length relative to runner ID flow size adds friction and pressure differential that has to be overcome:
.
As it goes i did an impulse buy on a SCR semi PP intake manifold. Had an fd friend who went in another direction on his build and made me an offer i couldnt refuse.
you just need to stage everything relative to load and rpm, which has largely gone undone or even mostly in the opposite direction on here …
.
That sounds fairly straight forward as load v rpm is how I'm currently staging now and everything seems buttery smooth etc. The only drawbacks so far is my engine builder said the new 4 barrel lower intake manifold means my turbo cant sit in the same position with the HKS cast manifold. So it will need new plumbing all around.
12-07-21, 01:06 PM
