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So, a long long time since I posted on SAU, and my eyes glazed over a long long way back in this thread.

 

Here is the bones of it, I have had my track car off track for nearly three years for a full wiring and electronics refresh (Wiring, PDM, dash, ECU) and as usual time and money had their way. Long story short I hope to have the car running again in the next month or so.

 

The car has a GT2860RS (.64 exhaust housing) on a redtop RB20DET making 208RWKW on 98 RON at 18PSI while being nice and snappy for the usual uses of the car, short tracks with slow corners and hillclimbs. The turbo is on one of those horrid little T3 to T25 adapters on the standard manifold and I would love to get rid of it. 

I know the RB20 in any guise is getting long in the tooth but have people had much success with the EFR turbos on these? The only advice I have had is "Go a size bigger than you think'. What I would love is if the newer design would give me the same kind of small turbo responsiveness without choking it as much at higher revs. 

My biggest wants on a conversion would be marginal to no loss of lower rev range performance, T3 bolt on (Unless the T3 to T4 adapters are a better thing than the two part T3 to T25 ones) and after that a bit of an extension of higher RPM capability. Am I dreaming?

My other thought was to build an adapter to take it to a V band turbine and fit the .72 A/R housing and an external gate.

Hey Blue,

I've got an EFR7163 on an SR20DET, so not too dissimilar setup. I am running e85, and have had a couple of issues with back pressure with a T4 TS mani and internal gate.

I can certainly attest to the response with a 'big' 7163 on a 2 litre. I'm running 307rwkw currently and making 250rwkw at 4000rpm. I have VCT, fairly small cams and as I said e85 so all that will help a little with response.

There's no T3 options in the EFR range (that I've seen). So you're on t25, vband or T4. I would think a 7163 in vband (the largest rear, which is a good thing for these) and external gate would be the way to go. Hard to say without knowing exactly how responsive your current turbo is. I would think 98 and ext gate would net you near 280rwkw and only lose a 'little' in response (compared to mine). FYI I'm not super familiar with RB20 setups.

For anyone else who had any interest in my setup / results I have some weirdness with my Nistune ECU and the HPX AFM. VCT is also rattling a little and getting tired. And can't really hold boost with internal gate. I'll probably switch to Haltech ECU for boost control, MAP sensor, OBD gauges, engine protection based on turbo speed rpm and a few other things. Hopefully that'll iron out some of the current bugs. Otherwise I'll just say f**k it and grab 2 x 38mm gates and go external setup which SHOULD get around the boost holding issue.

Dec2017-PostEngineRebuild-307rwkw-boost.jpg

Dec2017-PostEngineRebuild-307rwkw-power-torque.jpg

  • Like 1

Also Blue, the devil's advocate in me wants to also maybe suggest one of the new G25-550 Garret turbos. They come in a T25 with 0.49" rear which by the looks of their specs would get you a very responsive ~250rwkw on 98.
I'm certainly keeping a close eye out for results on the new Garret series.

(But I promise I still love my EFR guys, don't hate me) :)

Without digging too deep the 7064 can be had with a T3 flange, I would just need to dig in to maps to see how it compares with the potato. All this is a little by the by anyway as I doubt the money will be there to throw a new snail at it this year, but you never know. I can see up to about $5K between it and back on track as it is so it is not really very likely to be changed this year, but I tend to plan these tings a long way ahead.

The RS is snappy enough on it that I gave up on closed loop control with the previous ECU (Old E11 Haltech) as it was impossible to dial out big boost spikes at high RPM. The new ECU just about has more tables for closed loop than the E11 did for everything it had.

https://gcg.com.au/petrol-performance/performance-4/turbochargers-borg-warner/borg-warner-efr7064-turbocharger-t3-v-band-detail

 

Edit: Whatever ends up on it next what I would really like to do though is get rid of the split adapter. Aside from anything else I have had constant issues with the tiny T25 nuts and studs undoing in use. At least it was easy to get a lock tab for the T3 setup.

Edited by Blue
1 minute ago, Blue said:

Without digging too deep the 7064 can be had with a T3 flange, I would just need to dig in to maps to see how it compares with the potato. All this is a little by the by anyway as I doubt the money will be there to throw a new snail at it this year, but you never know. I can see up to about $5K between it and back on track as it is so it is not really very likely to be changed this year, but I tend to plan these tings a long way ahead.

The RS is snappy enough on it that I gave up on closed loop control with the previous ECU (Old E11 Haltech) as it was impossible to dial out big boost spikes at high RPM. The new ECU just about has more tables for closed loop than the E11 did for everything it had.

https://gcg.com.au/petrol-performance/performance-4/turbochargers-borg-warner/borg-warner-efr7064-turbocharger-t3-v-band-detail

3

Ah yep, I tend to forget about the 7064 for some reason. TBH wish I'd gone that direction at times to lose a little response for a better flowing rear (comes in 0.92 in T4 TS, instead of the 0.80 the 7163 comes in).

Again, hard to compare when I'm not sure just 'how' responsive your current setup is. What's the curve look like? When are you hitting max boost or torque?

3 minutes ago, MaximuSmurf said:

Ah yep, I tend to forget about the 7064 for some reason. TBH wish I'd gone that direction at times to lose a little response for a better flowing rear (comes in 0.92 in T4 TS, instead of the 0.80 the 7163 comes in).

Again, hard to compare when I'm not sure just 'how' responsive your current setup is. What's the curve look like? When are you hitting max boost or torque?

The 0.80a/r EFR7163 hot side flows the same as the .83a/r T3 EFR7064 hotside, and the .85a/r EFR7163 flows the same as the .92 EFR7064.  That dirty old mixed-flow turbine isn't a terrible thing.

Wouldn't a 6758 be closer to a 2860 in terms of performance? Bear in mind RB20 not 25 with vct and the trimmings.

 

Edit: T25 though so not ideal.

 

Still you have a 56lb/min turbo like the 7064 or 60lb/min in 7163 trim, or a 35lb/min turbo in the 2860rs, bit of a difference. Not sure either of those two would quite match the low end of the 2860, though transient may be better?

I can live with dropping a little lower RPM performance, so long as I can also live with the potential extra maintenance cost of anti lag!

One issue I face no matter what is the range of housings with a T3 flange is pretty limited.

Dyno sheets from when the car was tuned, I would not want to loose too much at the low end or midrange. Bearing in mind that the car could easily make more at the same boost, given the total lack of engine protection on the old E11 I asked for and received a nice safe tune. Before and after on these sheets is a proper tune at 18PSI versus a very rough track tune at 13.

R31 dyno sheet 1.jpg

R31 dyno sheet 2.jpg

R31 dyno sheet 3.jpg

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