Cam Timing- Rb26

[GTSBoy]

Lithium will probably crap all over this, because it's a quick and rough hack job, but it tells the story. The 7000rpm point, 23psi boost, is only ~700HP, low down off to the right of the island. The turbine match is good. It only takes a 29mm wastegate opening to bypass enough gas. Superficially, it just looks like you need to run more like 30 psi on a smaller engine. On this engine.... you would still be over to the right of the island if you were making more boost.

 

[Predator1]

10 minutes ago, GTSBoy said:

So what you need to do is plot where this operating point is on the compressor map and see why the efficiency is so crap and what direction you have to go in order to get it to work better.

The thing is, just because a turbo is "rated" at 900, does not mean that you can reasonably make that amount of power on a given engine. Let's take an extreme position on this. Instead of a 3.2, let's say that you try this on a 6 litre version of an RB26. Same efficiency as an RB, just twice as large. It is going to make about twice as much power for any given boost level, right? Or, more to the point of this, it will take a lot less boost at any rpm to make a given amount of power. So, let's say you want to get 900HP out of it. How much boost is that going to take to do that? A lot less, right? So it will be way over on the RHS and down low on the compressor map. Down where the efficiency is shit. Can you actually make it work from that position? Hell no. Anything you do here is just going to make it walk up the map towards the right. In the same direction as the island on the map runs, but off to the RHS. If you add boost, it will flow more air and you go up diagonally to the right. It will always suck. It needs a bigger turbo, so that at the lower boost levels required to make the power, it will be closer to the middle of the island on the map.

So, with this 9180, I have no idea where you'll be on the map at 800HP, but I'm willing to bet it's the wrong place. What we'd call a bad match. I'm going to go play with matchbot right now to find out.

Thanks, be keen to see what you come up with. I did plot this ages ago, IIRC it was around .62 on the map with a PR of around 2.6/2.7 (24psi). I understand that the turbo is a big limiting factor partly due to my head.

Im trying to understand whether playing with the cam timing would have helped out at all. Maybe even make the same power at a lower boost level or something.

[GTSBoy]

Here's what happens if I just mash the boost up on the 7000rpm point. 30psi and wastegating a bit more gas. Now you're flowing close to the limit of the compressor wheel, even less efficiency, and nowhere near the top RH point of the island, which is where you would prefer to be. This turbo wants a lot more boost to run efficiently, and it can't do it on a large engine. Still only making ~800HP. I tend to think the "900HP" rating might be a small stretch, but of course I haven't tweaked any of the other inputs for realism. There's a lot to play with on matchbot, and you can't really do it unless you know what is realistic for the combo.

[Predator1]

10 minutes ago, GTSBoy said:

Here's what happens if I just mash the boost up on the 7000rpm point. 30psi and wastegating a bit more gas. Now you're flowing close to the limit of the compressor wheel, even less efficiency, and nowhere near the top RH point of the island, which is where you would prefer to be. This turbo wants a lot more boost to run efficiently, and it can't do it on a large engine. Still only making ~800HP. I tend to think the "900HP" rating might be a small stretch, but of course I haven't tweaked any of the other inputs for realism. There's a lot to play with on matchbot, and you can't really do it unless you know what is realistic for the combo.

Yes this is exactly my point. I understand this. Here I was thinking it might do 1000 with all the other supporting mods I had.. I actually thought it would make that power as it wouldnt need as much boost, but thats the issue I guess, It cant flow enough air to make more boost! Wish I knew this before! 

 

EDIT - I dont have the final plot. She spat out i think 494 on 21, and 530~ on 23-24.

 

Attached my dyno sheets.

Edited May 20, 2023 by Predator1

[The Bogan]

4 hours ago, Predator1 said:

Yes from memory. I cant remember how much timing he added up top but it wasnt much at all. 

Apples and oranges: my supercharged LS1 would start pulling timing once IAT got over 65°c, some safety feature in the tune so I didn't melt pistons or something

At the drags the car would launch hard, but by half track the IAT was around 70°c and for the rest of the run the thing just dropped power

My fix was an interchiller, now my IAT haven't gotten over 36°c at the drags or during tuning on the dyno, the car runs like a boss now

Maybe look at the size of your intercooler, your CAI location, or, are you just maxing out the turbo and it is turning into a flame throwing heat gun, or does it need more fuel for cooling 

Well, that's where my uneducated brain and extremely limited knowledge about tuning would look IRT high IAT

[Predator1]

On 20/05/2023 at 5:36 PM, The Bogan said:

Apples and oranges: my supercharged LS1 would start pulling timing once IAT got over 65°c, some safety feature in the tune so I didn't melt pistons or something

At the drags the car would launch hard, but by half track the IAT was around 70°c and for the rest of the run the thing just dropped power

My fix was an interchiller, now my IAT haven't gotten over 36°c at the drags or during tuning on the dyno, the car runs like a boss now

Maybe look at the size of your intercooler, your CAI location, or, are you just maxing out the turbo and it is turning into a flame throwing heat gun, or does it need more fuel for cooling 

Well, that's where my uneducated brain and extremely limited knowledge about tuning would look IRT high IAT

Thanks man. Good to hear other people talking about interchillers. I actually emailed them a few times about doing one for me. I was super keen but I ran out of time as I had to leave countr(car is in long term storage now).

Im running a hypertune g2 110mm core which i would have HOPED be enough, but it could be the turbo itself. I have heard the Plazmaman is supposed to be better, but then, I ran out of time.

I dont have a CAI, I run a filter directly behind the Motive headlight with duct.

I really dont want to change my turbo as i love the response of the turbo... but at the same time, I wanted 1000hp *flamesuit on*

[The Bogan]

1 hour ago, Predator1 said:

Thanks man. Good to hear other people talking about interchillers. I actually emailed them a few times about doing one for me. I was super keen but I ran out of time as I had to leave countr(car is in long term storage now).

Im running a hypertune g2 110mm core which i would have HOPED be enough, but it could be the turbo itself. I have heard the Plazmaman is supposed to be better, but then, I ran out of time.

I dont have a CAI, I run a filter directly behind the Motive headlight with duct.

I really dont want to change my turbo as i love the response of the turbo... but at the same time, I wanted 1000hp *flamesuit on*

IRT interchillers, don't believe everything you hear with the marketing 

Don't get me wrong though, my interchiller is working great at keeping my IAT sorted, but, there are additional things that are required for a top mount blower, it needs thermal resistant spacers, mine are 10mm made from some apparently fancy plastic stuff, and some thermal mat on the valley plate to separate the blower from the engine, the heat soak from the block and heads does raise IAT readings, and thermal spacers and mat is recommended by FI interchillers

But with a turbo setup using a interchiller you won't have the heat soak from the engine effecting the intercooler that sits in the blower hat

I could upgrade the system by putting in a larger and more efficient condenser to get the most out of the refrigerant, and a larger reservoir for more volume to have more chilled coolant on hand, but for my usage it isn't required as I haven't seen IAT over 36°c during back to back drag runs and some time on the dyno

I am only pushing 7psi with the biggest pulley that fits though, I cannot really go a smaller pulley for more boost as I'm still on the stock bottom end and I am at the limit to keep my built 4l60e safe, which is 600hp at the engine

If you shut the car down, then start it up again in around a half an hour the IAT starts at around 40-45°c, and takes at least 5 minutes to drop back down to around 25°c

Disclaimer: on a turbo car, when you are at WOT for extended periods, like track sessions, the AC shuts down at high throttle percentages, I probably wouldn't use a interchiller on a WTA cooler, a normal air to water may well be more efficient, or, a normal air to air would most likely be a better choice, maybe????

Also, if you lose AC, the thing heat soaks, alot, they remove the WTA condenser when they fit the interchiller 

But, maybe/probably, high IAT temps aren't you problem like they were mine when I only had a WTA cooler

Good luck finding your issues and "may the boost be with you"

[Dose Pipe Sutututu]

20 hours ago, Predator1 said:

Im running a hypertune g2 110mm core which i would have HOPED be enough

Do you have any data pre/post intercooler boost pressure? What are your IATs at post IC?

I've heard rumours (just rumours no actual data or facts) that a few people swapped over to a Plazmaman core and IATs dropped, less of a pressure drop was observed and overall more power was made (but I have not seen any data to back this up).

On E85, IATs aren't too much of a concern, so I wonder what your tuner has set in terms of ignition trimming vs. IAT. I personally remove any aggressive correction on E85, and don't apply anything till 60 degrees IAT.

[Predator1]

I dont have that data sorry. I have IAT's post FMIC by the inlet. I've attached a video that outlines the ECU logs during a pull on high boost at around 10pm.

I also heard the same re Plazmaman!! A bit disappointing because Hypertune f**kED me around for a f**kING year for my FMIC, and ended up costing me just under 3k. I'll never f**king deal with those dream boats again from Hypertune. Absolute f**king dream boats! They almost doubled the cost of their 'special heat reflective' coating. Assf**king cumgobblers. Rant over.

What I dont understand is why my IAT's are so high.. if my turbo is out of puff, then why is my fkn IAT's sky rocketing after every pull?

IMG_4834.MOV

 

EDIT - You can also see my eMAP too mapped against RPM etc. Peak turbine speed is 103k too. I think max rated for the 9180 is 108k?

Edited May 23, 2023 by Predator1

[GTSBoy]

15 minutes ago, Predator1 said:

if my turbo is out of puff, then why is my fkn IAT's sky rocketing after every pull?

That is why. Running off the efficiency island means making hot air.

[Dose Pipe Sutututu]

Apologies if you've said it before, but how's your exhaust designed/plumbed? 

Yeah Hypertune, a few too many stories and their customer service is non-existent unless you're a big workshop.

Your IAT looks ok, however would be great to see what your pressure is pre/post.

EMAP doesn't look bad either. 

[The Bogan]

As Dose said, 30°c IAT is fine

How locked in are you to your current tuner?

What spring is in the gate?

[Predator1]

18 hours ago, GTSBoy said:

That is why. Running off the efficiency island means making hot air.

Ah! Really? Hmm Okay I stand corrected then. Thank you for clearing that confusion for me.

 

18 hours ago, Dose Pipe Sutututu said:

Apologies if you've said it before, but how's your exhaust designed/plumbed? 

Yeah Hypertune, a few too many stories and their customer service is non-existent unless you're a big workshop.

Your IAT looks ok, however would be great to see what your pressure is pre/post.

EMAP doesn't look bad either. 

I have a full 4 inch exhaust with 60mm TurboSmart and on a 6Boost manifold. I also have a screamer setup but i dont use it as its scary loud(exits behind the front wheel). I dont run any cats, just a muffler out the back. I have a 17psi spring in there, hence why the turbo speed tails off a little.

eMAP doesn't look bad? Its over 1:1 ratio. In the video, I did a 3rd pull. I stayed 100% TPS but buttoned off in 4th, hence the emap dropping off.. but 27psi for emap and 24 for mgp seems pretty high.

I've tried 2 tuners. The car made the same power on both dynos. SAE it made 556 and J1 530~ on the same boost. Both tuners didn't put any timing because of the boost issues, Plus the first tuner couldn't keep the boost up in high RPM's.. this was fixed by the 2nd tuner re-doing the boost tables or something, so now my boost is pretty stable.

The 2nd tuner was actually pretty helpful in trying to diagnose the issues.. He's pretty sure the turbos out of puff. We also checked for boost leaks, and smoke tests, and did spanner checks, and couldn't find a single leak. Im only using 1 silicon fitting. The rest are fkn ripoff Hyperf**kingshitTune wiggins style clamps.

[Dose Pipe Sutututu]

eMAP is not bad at all! @Predator1

What are your AFRs like? Also do you have EGTs by any chance? Let's say theoretically a few injectors are running a bit lean, your overall combined average AFR would be lean, naturally a tuner would dump in more fuel to make the average overall number look safe again.

Now because of that, you're dumping in much more fuel than needed and overall making a little bit less power than expected.

Not saying that it's the case, but good to rule out one more thing. Lastly, just to rule it out, just dump your wastegate to atmosphere for a dyno pull and see if you make heaps more power.

 

What are other cars with the same-ish setup making?

[GTSBoy]

2 hours ago, Predator1 said:

Ah! Really? Hmm Okay I stand corrected then. Thank you for clearing that confusion for me.

Yeah, that's what the efficiency lines are all about. The lower the efficiency, the more of the work from the turbine to the compressor is turning up as heat instead of pressure.

[Predator1]

32 minutes ago, Dose Pipe Sutututu said:

eMAP is not bad at all! @Predator1

What are your AFRs like? Also do you have EGTs by any chance? Let's say theoretically a few injectors are running a bit lean, your overall combined average AFR would be lean, naturally a tuner would dump in more fuel to make the average overall number look safe again.

Now because of that, you're dumping in much more fuel than needed and overall making a little bit less power than expected.

Not saying that it's the case, but good to rule out one more thing. Lastly, just to rule it out, just dump your wastegate to atmosphere for a dyno pull and see if you make heaps more power.

 

What are other cars with the same-ish setup making?

 

Pic of AFR plot attached. Sadly no EGT's. Was on the cards but kinda ran out of time, and inputs on ECU are running very thin. 

9 minutes ago, GTSBoy said:

Yeah, that's what the efficiency lines are all about. The lower the efficiency, the more of the work from the turbine to the compressor is turning up as heat instead of pressure.

Thank you - I need to read up more on this.

[Dose Pipe Sutututu]

@Predator1 overall AFRs look good, to be honest the torque graph looks pretty sensible too.

I suppose the easiest option it to drop the plumb back external wastegate and do a run and overlay the graphs.

 

As @GTSBoy has mentioned the turbo is probably out of puff, however there are other thing to play around with to try extract more power.

[Predator1]

Yeah you guys are right. Dont get me wrong, she pulls nicely in any gear at any speed, even with the super long gearing on my sequential. I love the power delivery and shes pretty scary when she gets up in triple digits..

I was a bit disappointed my cams werent dialled in, therefore i was wondering what sort of figures i could potentially make if it was timed correctly. Sadly I wont be driving her for a year or so.

[Dose Pipe Sutututu]

2 minutes ago, Predator1 said:

I was a bit disappointed my cams werent dialled in, therefore i was wondering what sort of figures i could potentially make if it was timed correctly. Sadly I wont be driving her for a year or so.

You could always pop it on your tuner's dyno and start retarding the exhaust cam gear 1 degree at a time, you'll see a drop off down low, hear a grumpier idle however would expect the top end to pick up!

[Predator1]

8 minutes ago, Dose Pipe Sutututu said:

You could always pop it on your tuner's dyno and start retarding the exhaust cam gear 1 degree at a time, you'll see a drop off down low, hear a grumpier idle however would expect the top end to pick up!

haha i would If I was in the same country as my car