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Interesting - I'll see what I can do about checking that eventually. Now I'm quite curious.
i went down the turbo rabbit hole, and to figure out where you are on the turbine and compressor maps, you need the pressure in and out. we know the compressor side well enough, but it sort of turns out that if you look at the turbine side too, it kind of tells you what you need to change to make more power, and it was easy enough that i could figure out how to do it.
i just pulled the old 7psi backpressure exhaust, and put on the ridiculous overkill 92mm exhaust and we will see what that does
Given that the intake and exhaust all look to be up to the task but the numbers don't look right @18psi ..... I'd be looking for a boost leak. Looking at the pics I see what looks to be a Greddy BOV ........ I've seen these cause issues before so that would be worth testing.
My genuine Greddy Type RS would pop open over ~14psi unless I screwed the adjuster all the way down to where it could only open ~1/8" when venting.
Didn't want to be too critical but yeah ..... anytime I've tuned a setup with that BOV I always end up telling them to throw that f'n thing in the trash !
For the BOV- you can try loosening the 10mm locknut and screwing the adjuster at the top of the BOV all the way in and relocking the nut.
Then see if you boost higher. Make sure you have an overboost safeguard or plan in effect.
Boost leak test for rotary is-
Plug exhaust.
Plug turbo inlet with air compressor fitting tapped in it.
Plug into air compressor with a big tank and regulator set to ~40psi.
Rotate engine with socket till hissing is quietest.
Listen and feel for leaks or spray soapy water on everthing that could leak.
For my edification purposes, what leads you to think a boost leak is a culprit here? I understand that it could slow the climb to the threshold, but wouldn't we see more variation in the line once the threshold is achieved? Seems like a leak big enough to slow the climb to the threshold would be enough to be notable.
Wouldn't AFR be a bit more wandering? Why would it require a higher sustained boost than anticipated for the ~400 hp? Seems like it would still require the same boost level but have a harder time maintaining it.
when I said intake and/or exhaust restrictions I meant from the air filter all the way to the exhaust tip
because I haven’t a lot of time recently to read through some of the novel-length posts here, but just tried to speed-read through them and I’m not seeing if this is ported or not, or what turbo manifold is on it, and other details. I may have just overlooked them though.
that said, I’m up here in DFW sitting on a G30-770 1.06 T4 with the car torn apart and not being touched for the last two months. It should be a direct bolt-in. If you want to try it out and see the difference then send me a pm. Kind of sticking my neck out, but nothing new in that regard
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when I said intake and/or exhaust restrictions I meant from the air filter all the way to the exhaust tip
because I haven’t a lot of time recently to read through some of the novel-length posts here, but just tried to speed-read through them and I’m not seeing if this os ported or not or what turbo manifold is on it, and other details. I may have just overlooked them though.
that said, I’m up here in DFW sitting on a G30-770 1.06 T4 with the car torn apart and not being touched for the last two months. It should be a direct bolt-in. If you want to try it out and see the difference then send me a pm. Kind of sticking my neck out, but nothing new in that regard
edit: direct bolt-in on the turbine side, but the compressor being slightly different might need some finessing on the cold side.
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For my edification purposes, what leads you to think a boost leak is a culprit here? I understand that it could slow the climb to the threshold, but wouldn't we see more variation in the line once the threshold is achieved? Seems like a leak big enough to slow the climb to the threshold would be enough to be notable.
Wouldn't AFR be a bit more wandering? Why would it require a higher sustained boost than anticipated for the ~400 hp? Seems like it would still require the same boost level but have a harder time maintaining it.
A large boost leak means the turbo has to supply much more air to achieve the set boost level. The turbo is working harder to do this which in turn raises EMAP . Higher EMAP means you need more boost to make the same power. You are tuned with an ecu that measures boost and has no idea how much air is actually flowing. So when you fix this ...get a retune before going WOT.
As per Brett's post, there is a compound effect of additional pumping loss on exhaust stroke with higher EMP to drive the turbo and lower VE due to that same carry over. That's why people often step up to IMP:EMP based load models.
I'm told the BoV is working appropriately. No other leaks were detected - all new hoses, gaskets, couplings, etc.. As far as Rotary Performance is concerned, everything is working as intended and I'm inclined to believe them. Damn near every part of the car has been checked, replaced, or upgraded. Chris has continually reaffirmed that everything is as it should be and most of this is likely indicative of how this turbo plays with this setup and that 100+ degrees with over 55-65% humidity is a torture test in terms of dyno results.
Originally Posted by TeamRX8
when I said intake and/or exhaust restrictions I meant from the air filter all the way to the exhaust tip
because I haven’t a lot of time recently to read through some of the novel-length posts here, but just tried to speed-read through them and I’m not seeing if this os ported or not or what turbo manifold is on it, and other details. I may have just overlooked them though.
that said, I’m up here in DFW sitting on a G30-770 1.06 T4 with the car torn apart and not being touched for the last two months. It should be a direct bolt-in. If you want to try it out and see the difference then send me a pm. Kind of sticking my neck out, but nothing new in that regard
edit: direct bolt-in on the turbine side, but the compressor being slightly different might need some finessing on the cold side.
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Mild street port, manifold is "meh" but has proven to be ok in supporting my power target well previously - it's the same that was on before with fairly excellent results (at the time). While it's clearly not the best I can't imagine it being a drastic handicap to the point of "something is wrong" levels. This... thing...
Other than that, no other unexpected restrictions to speak of - stock UIM, LIM, and double throttle removed.
I would absolutely love to throw the G30-770 on. I'll PM you and see if we can line something up. The car will be in the Dallas area for a while longer after the mechanical refresh is complete as it will be going to paint in the next few days. No idea how long that will take, however. So maybe we can make something happen.
I'm told the BoV is working appropriately. No other leaks were detected - all new hoses, gaskets, couplings, etc.. As far as Rotary Performance is concerned, everything is working as intended and I'm inclined to believe them. Damn near every part of the car has been checked, replaced, or upgraded. Chris has continually reaffirmed that everything is as it should be and most of this is likely indicative of how this turbo plays with this setup and that 100+ degrees with over 55-65% humidity is a torture test in terms of dyno results.
There is no way you get a result like that unless there is something wrong with either the turbo, your system or maybe the dyno itself. IMO everything is NOT working as intended. I don't believe the design of the setup or the atmospheric conditions are to blame.
Knowing how bad those particular BOVs are ..... I still think that is the most likely culprit. Ask them how they tested it - just because it makes choo choo noises doesn't mean it's working properly. If car was on the dyno easy way to test would just be to put your hand over it while running it up. Other than that you could fit a blocking plate to take the BOV out of the system altogether .
. Other than that you could fit a blocking plate to take the BOV out of the system altogether .
that is what i would do.
1. wash hands
2. buy canned drink of your choice
3. drink said drink
4. remove BOV
5. cut can into gasket with no hole
6. reinstall BOV (or acv, isc, bac, etc)
7. winning
It would be interesting to know if your car is capable of performing a 100-200kph acceleration test a few times to get a base line. It will provide a good indication of real-world performance. Additionally, could you clarify if your car has a power output of 400hp at the rear wheels? If yes, considering you're running pump fuel without AI on a conservative tune...I wouldn't expect you to make more?! It doesn't make sense why there is an expectation to be running 450rwhp/475/500rwhp on your current setup/tune?? it doesn't make sense to me.
It's just a dyno number, you wont know real world performance unless you test it. We all spend ££££s on setup but not many of us are willing to spend £140 on a dragy gps device to actually test real world performance after a dyno run.
There is a lot of "should" be. Nothing wrong with that, and I get that the G35 "should be" doing something else, but I can't keep paying to chase a ghost that may not be there especially if they don't think there is something wrong after multiple different questions. What should be is often different than what is. Right now, I have what is.
This goes back to the original point of this thread: Do we have any dyno results with a G35-900 on a REW?
I can't compare it against a G30 and say that something is wrong with a G35/my setup - the answer may be I should have bought a G30 (which if the stars align we may get to see). Now, I could certainly go back to them with another dyno result of a G35-900 showing very different results and say something is wrong.
Try to post up a real world 100-200kph valid dragy result, that will tell you far more about the consistency and reliability of your overall setup than a dyno number. Same with the G30 dyno queens you have no idea how fast they are in the 100-200kph sprints!
a G35-900 1.06 T4 should be capable of mid-500 range with all the correct mods and support components
in addition to the weak boost curve up to 4000 rpm, looks to me like there are flow restrictions on the intake and/or exhaust. Some of it appears to be conservative tuning possibly. The one advantage of the Renesis is that the factory 6-port intake/ports will flow better than the factory REW intake/ports, enough to support 270 bhp NA. Which was what the REW TT was rated at from the factory.
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That boost curve looks very typical for a Non divided manifold from what I have seen. (yes divided with single waste gate does not count as divided)
another option would be that Pulsar offers both a 0.82 A/R open T4 and 0.85 A/R div T4 turbine housing for their equivalent G35 turbo. They’re direct fitment on the Garrett G35 and SS material too, but ~1/3 the cost of a Garrett housing. Which the div 1.06 A/R is the only T4 option that Garrett offers. Those tighter A/R values are more fitting for the 400 whp range and are going to flow about the same as the G30 1.06 A/R housing.
Which I just noticed that Pulsar is now offering the -770 compressor on their equivalent G35 turbine assembly. So their PTG5862 div T4 0.85 A/R (~G35-770) is an alternative to Garrett’s G30-770 div T4,1.06 A/R as well. Which they also offer as a PTG5855, along with a div T4 0.85 A/R option for it too (and the Garrett G30).
🤔
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I finally have the car back from the body shop and I have been able to put some miles on.
Initially, a bit overwhelming. The car is totally different so it took a bit to acclimate. Sounds, clutch, smells, looks, everything is very different. Quite an experience, much like driving her again for the first time. If I didn’t know any better I’d say it was another car.
My first impressions were there was something wrong. Things didn’t feel right, felt like a boost leak. And, there was – my boost gauge had popped off the UIM – I didn’t even notice it at first as I was dealing with a new clutch/flywheel combo in downtown Dallas traffic (yay chatter!). This, however, was not an issue on the dyno as that connection was used for something else.
Anyway! That rectified, the car felt a lot more like I expected as I settled into being comfortable with her again.
The G35-900 is nice, spools about as fast as the GT35R did in cool weather meanwhile it was 112f when I picked her up. Full boost around 3900-4100 RPM. Doesn’t seem as on/off as the GT35R before did. The slightly surprising thing is just how loud the turbo whine is – I feel like a diesel truck in terms of how loud the turbo is compared to the GT35R. The threshold response is slower than I would have hoped for and I feel like at the end of the day it was a lot to spend on new technology for similar results. Now, if I was going for 450+ hp – I think this turbo would really sing. For my application at 350whp, I’m on the low end of its performance and it was not worth the price difference vs old tech (or perhaps the G30-770). I’ll have to wait until cool weather to get a true feel comparison as I very, very rarely drove her in anything other than cool weather due to potential heat issues in the past.
Overall, not disappointed, but not blown away.
The car as a whole, however, is remarkable. If you haven’t gotten a transmission brace by now, you really should. 2nd and 3rd are “right there” every time. Differential brace, all new pillow ball bushings, motor mounts, etc., etc. make for an exhilarating shifting and driving experience and I have no wheel hop anymore. Quite the impressive difference.
The V-mount and dual oil coolers actually have me concerned about overcooling - which I never, ever, thought I would say about a 7. 110f+ degrees ambient temps with AC blowing in stop-and-go traffic and I never saw above 90c. Cruising home at night in 98f ambient I never saw above 84c water temps traveling at ~80 mph for almost 4 hours.
I’ll see about getting a draggy at some point but I need to let the wallet cool off a bit.
the old school folks just can’t get past the idea that the new GT35 is now a G30, because the G30-660 would have been so much better response at 350 whp.
but just be glad they didn’t pull a Rob Dahm and bog you down even more with a G40-900 instead.
there should be benefits that aren’t readily discernible from the driving perspective though; lower emap and IAT will favor long term durability.
you do still have the Pulsar 0.85 A/R div-T4 turbine housing option to improve response at some later time to get it closer to what the G30 would have been.
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the old school folks just can’t get past the idea that the new GT35 is now a G30, because the G30-660 would have been so much better response at 350 whp.
but just be glad they didn’t pull a Rob Dahm and bog you down even more with a G40-900 instead.
there should be benefits that aren’t readily discernible from the driving perspective though; lower emap and IAT will favor long term durability.
you do still have the Pulsar 0.85 A/R div-T4 turbine housing option to improve response at some later time to get it closer to what the G30 would have been.
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This. The Turbine Efficiency of the G-Series is really "upclassing" everything from old school nomenclature.
As much as the numbers seem odd on Garrett stuff when it comes to the lbs/min of airflow being "undersized" compared to the BorgWarner stuff, in reality, they use different "corrected" airflow values and the Garrett stuff is actually doing MORE than it's been known to.
Don't get me wrong, if EFRs were widely available still, I'd be suggesting them hand over fist for response-kings, but for pure efficiency for a given size, the Garrett stuff is VERY good. A G42-1200 Compact should closer line up with a GTX4508R in the real world, which is wild to think about...
As such, the G30-660, 770, and 900 will be great options for midrange punchy turbos. G35-900 and 1050 will be options for mid to high end on streetport, or bridgeport and semi-pp engines on midrange focus. G40-900 and 1150 will be amazing for a high end streetport or mid to high end bridgeport or semi-pp, and G42, G45, etc will be for the huge power boys.
So yeah ... the G30-660 (or 770) would have been the turbo to choose, but I understand why you were swayed by the sales guys. They are always very convincing, even if they wouldn't know a turbo from a bilge pump.
That plus I'd still like to see you test the BOV - I have even used a cellphone to do this in the past . Just find a quiet stretch of road tape a streamer or something in front of the BOV , tape your cellphone somewhere so it can video the bov exit , hit record then take off through first and second should be enough. Stop and review the recording. If streamer is flying as you accelerate - bov is leaking, and that is why you need so much boost to make the power you are making.
06-28-23, 02:42 PM
