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Turbo Talk! Critique choices for a 450bhp redblock

Rad, thanks for posting all of that. Stiggy will have to decide how relevant it is to compare your data to his Redblock, but it's got to be in a similar ballpark.

To translate turbocharger sizing into modern Garrett nomenclature it would be something like a "GT3370." The old Stage3 T3 turbine wheel is 65mm on the inducer, and the T04B v-trim compressor is 70mm exducer. So that ratio is 1.08, and for comparison a GTX3576R has a compressor/turbine wheel diameter ratio of 1.12, and the 3071 is 1.18, 3067 is 1.12, and the G25-660 is a pretty large 1.25 but the modern wheels work in such a way that it's not as drastic as it seems.
 
I mapped out these just for fun

GT3071R.jpg


GT3076R.jpg


3576R
3576R.jpg


7670
7670.jpg
 
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Since your car run and drive, why not spend a little money to get the car on dyno and datalog it.

da89d98f2db809185b9966e1c59c5b9f96d6172476ac60bd1247cd4d7144c7fe.jpg


the car is actually not currently running, it's down for an overhaul and part of the script is the turbo swap. Realistically not going to put it all back together just to go do a dyno and take it all back apart. Good advice just not practical.
 
If I was shopping for a turbo, GT3071R would be out as there is very little head room for my 353whp engine.

It would be between EFR7670 and 3576R for me.
 
If I was shopping for a turbo, GT3071R would be out as there is very little head room for my 353whp engine.

It would be between EFR7670 and 3576R for me.

Thanks, that seems to be where I'm narrowing in. Appreciate the input.

Hope I didn't seem too dismissive of your previous advice, but not something I think I can realistically pull off.
 
Hope I didn't seem too dismissive of your previous advice, but not something I think I can realistically pull off.

May I ask you why didn't you dyno it when you had it all running? It can provide very useful information and more importantly, bragging rights. :oogle:
 
May I ask you why didn't you dyno it when you had it all running? It can provide very useful information and more importantly, bragging rights. :oogle:

great question. It is not hard to find a place to strap the car down and offer me no help. It is hard to find a professional who was willing to work on a real tune on the car with the megasquirt setup, which is what I really wanted. Given that, I just never had a big motivation to run the car as I'm not a good enough tuner to really capitalize on it. So figured eh, street driven, street tuned, just keep jamming it. I also come up with some kind of big change every year so fell into the "well I don't want to dyno it until the new motor is in, then the new clutch, then the this..."

Part of my goals here is that I'll come out of storage with a few last things sorted and then go get a damn tune done finally. If I truly can't find a shop who wants to play with megasquirt I'll just keep doing what I'm doing for another year or so, then I'm going to ditch MS and move on to something I can have dealt with locally (this is in the long term plans for the car regardless)
 
the maps make the S257 look the best. This is where I wonder where the maps aren't telling the whole story.

maybe I'll just rebuild the damn holset after all :roll:
 
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I really doubt you'll be flowing over 60 lb/min... was that operating point specific to your setup or taken from some other comparison?
 
I really doubt you'll be flowing over 60 lb/min... was that operating point specific to your setup or taken from some other comparison?

I'd tend to agree. It's ostensibly based on my setup, here's what I gave him:

Car is a Volvo 242 with a Volvo b230ft engine
2.3l 8 valve, 96.5mm bore, 80mm stroke
8.5:1 SCR, built bottom end and a high flowing head, 7000rpm rev limit
twin scroll tube header flanged for t3
I have been running a 12cm HX35 for a few years
goal of ~450bhp on 93pump

It's a street driven car with an occasional track day. Looking to improve overall power output and transient response over the HX35. A slight improvement in spool would be nice but not necessarily the primary objective, currently seeing 23psi around 3900rpm. I am mostly looking for better on-off throttle response without sacrificing top end.
 
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Am I the guy being referenced? I meant I didn't/don't think you'd be happy with a turbo with max flow below ~65 lb/min. Just doesn't seem worth it to me because I bet you'll want more power in the future. I don't think you'll be flowing the 65 lb/min, but I think you'll want the headroom. I just know at my altitude, my 7064 was out of steam and not doing what I wanted, so I got the 7670 for the extra 10 lb/min flow.
 
Am I the guy being referenced? I meant I didn't/don't think you'd be happy with a turbo with max flow below ~65 lb/min. Just doesn't seem worth it to me because I bet you'll want more power in the future. I don't think you'll be flowing the 65 lb/min, but I think you'll want the headroom. I just know at my altitude, my 7064 was out of steam and not doing what I wanted, so I got the 7670 for the extra 10 lb/min flow.

Ah ok, sorry man. I thought maybe Mike got this from someone on vwvortex since the plots looked identical to that thread referenced earlier.

Certainly valid to build in some headroom for future improvements. But at around ~3.0 pressure ratio a 2.3L / 7000rpm redblock is maybe only ever going to reach 55 lb/min.
 
Ah ok, sorry man. I thought maybe Mike got this from someone on vwvortex since the plots looked identical to that thread referenced earlier.

Certainly valid to build in some headroom for future improvements. But at around ~3.0 pressure ratio a 2.3L / 7000rpm redblock is maybe only ever going to reach 55 lb/min.

No worries at all. Maybe he did talk to someone else. I'm not sure if I'm the guy he's referencing. I didn't make any of the plots he's posted; we've just been talking about my turbo selection since our setups are very similar.

I agree with you. I'm just trying to say I'm much happier with my 7670 than my 7064 and can hit my boost target.
 
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Maybe he did. I'm not sure I'm the guy he's referencing. I didn't make any of the plots he's posted; we've just been talking about my turbo selection since our setups are very similar.

I agree with you. I'm just trying to say I'm much happier with my 7670 than my 7064 and can hit my boost target.

My fault - I should have never been born. If I'd never been born then none of this would have ever happened.

Looking at the compressor map for an EFR7064 I can see why you were running out of steam. I adjusted this match sheet I've been playing with for 4950 ft elevation (so 12.2 psi ambient pressure) - at about 2.5 pressure ratio, 46 lb/min, you were way over near the choke line and getting down towards 60% efficiency or lower. Certainly appropriate to jump up to a higher-flowing compressor at that point.
 
My fault - I should have never been born. If I'd never been born then none of this would have ever happened.

Looking at the compressor map for an EFR7064 I can see why you were running out of steam. I adjusted this match sheet I've been playing with for 4950 ft elevation (so 12.2 psi ambient pressure) - at about 2.5 pressure ratio, 46 lb/min, you were way over near the choke line and getting down towards 60% efficiency or lower. Certainly appropriate to jump up to a higher-flowing compressor at that point.

Lol. I'm really not offended in the slightest. I defer to you (obviously, you're the expert) and was mostly basing my recommendations on my own circumstances, which don't really match up with his. When I drove my car with the 7064 at sea level the response was so good that I don't think the jump to a 7670 is unreasonable.

It's even worse than 4950 up here. The last time I was at the track, the DA was 7500 ft. I just needed to move my map to the right a bit to get to a more efficient point.

I have played with Borg Warner's match bot, but I'm sure it's overestimating my mass flow, although I am at around a pressure ratio of 3.6. I would really be interested in knowing the VE of a worked over redblock.
 
Damn, 7500 ft. DA is pretty extreme. In that case yes, you will get near 60 lb/min at 3.6 PR. Not sure if Stiggy would ever need to operate there though.

76mm compressor does seem like a smart choice for his engine, even if it won't be using the whole available flow range.
 
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