Ian_D

This is a thread on my RX8 single turbo 13B REW build.

In reading anything I write here, please bear in mind the following:
• I have taken it on myself to give aerodynamics a design priority and I recognise that a lot of what I’m doing may seem **** or over-the-top. For good or evil, I have a previous life as an air force engineer with a lot of time on aerodynamics and therefore want to do the best that I can achieve, even if that means spending hours on what others may think irrelevant.
• I am trying to keep costs down and have, where practical, tried to use what I have and do as much work as I can myself.
• I am in the UK which means that:
o I may have to do something different as I can’t get many components that are easily available in the US and those that I can tend to be notably more expensive.
o I’m used to terms that are often different in the US. I’ll therefore try to include both metric and imperial values and give alternative terms such as bonnet/hood and boot/trunk. However, this duplication can be a PITA so forgive me if I miss a translation.

Why the Thread

I’ve been working on my own 13B REW conversion for a while and have found a great deal of help on the forums here. I started a build thread a while ago and let it lapse as it was clear I lacked the time, experience and practical knowledge for it to be useful to myself and others. I now think that I’ve got my act together and can start a new thread.

I am, though, not a typical conversion builder and start from a different baseline – I bought what I thought was a complete professional conversion only to find I’d bought a crock of sh*t missing many of the claimed component.

My Car Before I Started

The previous owner had a 13B REW and T72 turbo fitted by a professional rotary engine builder, hereafter called ‘The Bodger’. The previous owner made further modifications such as an orange sparkle vinyl wrap, a carbon bonnet, uprated clutch, lightened flywheel and ultralight, wide wheels. The car was featured in a national car magazine and was displayed at numerous national car shows.

The Start

The car seemed fine on the road but as soon as I took her on a track day things began to fall apart. After a lap power started to drop off then she just died in the pit lane; although we found a large fuel leak (rather than use a proper bulkhead connector, The Bodger had pushed the end of the return line into a hole drilled in the fuel pump basket roof then secured it with epoxy glue that soon gave way), a dozen rotary experts couldn’t get her going again so she made the drive of shame on the back of a transporter.

The cause of her dying, an unsecured fuel pump resistor’s burning out its wiring on the exhaust manifold, was easily and quickly rectified. However, my investigations into the power drop opened up a can of worms that started with my thinking the intercooler was too small and badly positioned and will end with my redoing everything except for the core engine and engine mount (a bastardized RX8performance one). Each issue I investigated seemed to turn up 2 more until I’d ripped out everything but the basic chassis, core engine and gearbox.

I started by completely replacing the fuel system and electrical power distribution. Then real life intruded; I couldn’t do anything hands-on for a long, long time and had to content myself with a keyboard and lying under my car dreaming up 101 options for fitting everything into the engine bay, 99% of which almost work. The tables have now turned and, having planned most things, I can start to get my hands dirty again.

Ian_D

Here follows a summary of where I stand now. In reading this note that I am building a road car with track use (say, 6 track days per year).

Aerodynamics
• I have written a thread on aerodynamics for turbocharged RX8s here.
• As mentioned above, I’m placing aerodynamics as a major consideration even it that means having to put in a great deal more thinking, time and effort than is justified for the result.
• My main effort has been into airflow for cooling systems.
• Many aerodynamic features such as front wing/fender grilles, diffusers, full-size splitters and wings are either impractical, over-the-top or both for a road car. Others, such as a slot in the bumper to direct air over the wheel well, are tempting but will be a complete waste of time and effort without proper testing that is impossible for me to do.

Air box and filter
• Cone filter in new-build airbox.

Audio
• Replace BOSE system with modern single or double DIN head unit with remote fastened to steering wheel TBD, Amplifier (Focal FPS2300RX 2 x 155 W RMS) powering Morel Elate 3-way speakers, Focal 165VR speakers in rear powered by head unit, 8” Focal sub in bespoke box replacing ski hatch powered by Pioneer 500W RMS mono amp.
• Nexus tablet in sat nav hood linked to head unit to provide sat nav, music storage, internet browsing and link to Adaptronic ECU to display parameter outputs/inputs.
• Phone cradle with link to head unit.
Bodywork
• Retain vinyl wrap.
• Keep relatively standard to remain original look and avoid expensive rewrap or repaint.
• Retain Seibon bonnet/hood, make best use of existing grilles and replace bonnet catch with bonnet pins.
• Fit R3 sideskirts and paint in orange metallic.
• Small air dam and splitter under bumper balanced by Seibon carbon fibre ducktail spoiler on rear.
• Option for deeper front splitter, rear wing and, possibly, rear diffuser (a proper one, not a cosmetic one).
• I’ve so far not been able to find a good use for the vents behind the front wings/fenders. I don’t want to widen the small vent holes in the structure behind them as I’m concerned over rigidity and crash performance. I could cut through to vent air from the rear of the front wheel wells but the effort and spray on the bodywork hardly seems worth the gain.

Brakes
• Currently fitted with slotted rotors, track/fast street EBC Yellowstuff pads and SS brake lines. Have been keeping an eye out for a BBK.
• Brake cooling (see my write-up on what I did on my R3 here).

Cabin heating and air con
• Had air con removed during conversion.
• Fitting air con is not a simple job (see the thread here). I am undecided between biting the bullet and doing it now or waiting to see how I get on without it.
• I’m wary of the cabin air intake getting the warmer air from the bonnet grilles. I’ll be investigating later and may have to reroute the intake.

Cooling: All
• There is insufficient room in the nose and engine bay for my ideal cooling and air intake systems and the associated ducting, piping & electrics. I have therefore spent countless hours dreaming up and assessing 101 different ways of putting all the cooling systems together, often meditating lying still under my car for what seems like hours, much to the consternation of my neighbours who thought I’d died there.
• I made a mock-up of the bonnet/hood and a cross-sectional plot of the engine bay to help plan and assess the various options.
• I’m coming down to 2 basic options, one with a V-mount configuration, probably with the radiator more vertical than canted back, and one with a front-mount intercooler (FMIC) and canted radiator, as shown in the 2 plots. Both have the oil coolers in their current locations.
• I’ve mocked up the FMIC configuration complete with representative tubes, hoses and wiring, and will be doing the V-Mount configuration in the next day or 2. I’ve not yet decided between the 2, although I intuitively prefer the FMIC for its expected better cooling; however, the V-mount has advantages, notably I can leave the crash bar in place whereas the FMIC will need awkward strengthening.

Cooling: Charge air (Intercooler)
• I went through several iterations of intercooler design in order to get the best size and end tanks for the location. I am currently looking at a core of 3”x12”x18” (76mm x 305 mm x 458 mm).
• I want a proper core not an eBay special and have therefore bought a Garrett one – a wonderful piece of work, if heavy.
• I’ve spent hours designing the best end tank configurations then searching for them off-the-shelf or for someone to make them to my design, all so far without success. I’m therefore rapidly becoming disillusioned over being able to produce end tanks to the aerodynamic standards I’m looking for.
• I’m planning to fit bungs to each side of the intercooler so that I can measure temperatures and pressure drops in use.
• I calculated the optimum tube/hose size as 2.5” and will be using that between the compressor outlet and intercooler. However, for the intercooler exit I may use 3” tube/hose as I’ll be using that to smooth the air flow before the MAF and it seems to make little sense to compress the intercooler outflow into a 2.5” hose only to expand it shortly afterwards.

Cooling: Engine Coolant (Radiator system)
• I have a JDM RX7 FD upgraded aluminium radiator that I’m modifying to fit.
• I’ve fitted a modified FD fan housing and will probably fit a different thermostat/sensor so that the fans come on earlier than in the RX8 (assuming that the RX8 PCM will still control the fans).
• Using representative radiator efficiencies and estimated minimum cooling rates at engine idle with the car stationary, I estimated the radiator fan requirement as a total of 2700 cfm. Adding a safety margin this became a representative 3000 cfm at 5 psi. The radiator size limited the fans to 12” (300 mm), so 2 SPAL race fans were selected, one heavy duty of 1770 cfm as the main fan (RX8 M1) and one of 1469 cfm for supplemental use (RX8 M2).
• The Butcher bastardized the engine inlet housing so I have no heating hose connection, which has been moved to the water pump housing. I’ll sort this out when I do the turbo connections.
• I’ve a JDM swirl pot for the exit of the water pump housing. I may have to modify it to avoid the turbo’s compressor housing.

Cooling: Gearbox
• I’m heavily tempted to fit a gearbox oil cooler to keep temperatures down, and hence life up, on the track, particularly as I’m feeding less air from the engine bay over the gearbox and thought of panelling under the gearbox.
• I’ve had a quick look to see where I could fit the major components (supply and return connections, thermostat for pump operation, temperature sensor for monitoring, pump, lines and cooler/radiator) and decided it’s doable, albeit not straightforward, particularly over finding a cooler/radiator location that meets my high standards of aerodynamic efficiency.
• My preferred location for the cooler/radiator, under the bonnet/hood passenger-side rear grille, conflicts with my wanting to keep the system low-down at the level of the oil in the gearbox.
• I’m still in 2 minds over this. Even if I don’t go ahead now I’d like to have a design in my hand so that I can do it later with the minimum of fuss.

Cooling: Oil
• I’m thinking of retaining the RX8’s oil coolers as they fit the bumper holes well, are cheaper than buying replacements, seem to be pretty efficient and have thermostats built-in.
• I’m replacing all the oil pipes, hoses and connectors with stainless-braided AN10 hoses and upgraded connectors.
• I’m looking to relocate the oil filter and haven’t yet decided how. I could fit a standard relocation kit with its extra hoses, I can’t buy blanking plates to replace the pedestal here, I could modify the pedestal block from a relocation kit (so that the oil supply goes to the block and then distributed to the engine and oil pressure relief valve) or I could fit an RX8 pedestal.
• Oil pressure and oil temperature will be taken from either the filter relocation plates or from sensors at the oil coolers.

Electric supply
• Battery relocated to boot and all power distribution cabling uprated.

Engine bay bracing
• I’m intending to strengthen the engine bay with bracing in order to allow for the extra weight of the conversion and the loss of rigidity from removing metalwork such as the battery strut, parts of the engine bay front and, possibly, the crash bar.
• I want to avoid strengthening that will affect crumple zones such as that between the suspension towers and A pillar. I considered fender braces but decided against them for this reason.

Engine bay wiring
• As I was concerned over what bodges may be laying there, I checked and logged all my engine bay wiring.
• As a result of what I saw I will be completely redoing the wiring from fresh looms whether or not I change the engine management unit.

Engine management
• My car came with an Apexi PFC, RX7 throttle body and throttle cable. Had I been starting from scratch then I would almost certainly have started with an Adaptronic RX8 PNP, RX8 throttle body and RX8 throttle that would give me DSC.
• I’m not starting from scratch and the temptation to leave things as they are is huge – lower costs, less effort, lower risk and less hassle. I have therefore spent a long time musing over my options and have decided to get the Adaptronic.

Exhaust
• Currently fitted with Racing Beat SS Decat and SS Revi exhaust, both of which are 3” in diameter except for the 2.5” restrictions at the joining flanges, with a cat to be fitted for the annual roadworthiness test (MOT).
• I’ve not yet decided whether to have a completely new system in, say, a 3.5” bore or keep costs down by replacing the 2.5” sections and flanges with 3” ones.

Exhaust manifold and downpipe
• I’ve got new Mazda studs and nuts for the engine casing, although I’ve not yet tried to get the remaining 3 old studs out (one just came off in my hand, honest).
• As my car is RHD the steering column restricts me to a top mount exhaust manifold.
• I’m designing and cutting my own SS304 Schedule 10 twin-runner manifold and downpipe for a professional welder to complete. After some initial difficulties I tried to find one off-the-shelf but had to go back to DIY as I couldn’t find a specialist to do one.
• I intend to have the exhaust manifold and downpipe ceramic-coated to keep heat down then, if there is room, fit an Inconel heat shield or mica plate. I have an Inconel heat shield from an aircraft jet engine that I can modify, thus saving money and having a connection with my past life.
• I’ve spent a lot of time trying to find the best balance between design requirements (3” straight flow out of engine to maximise combustion, short flow length to reduce lag and minimise the stresses from having a turbo waving about at the end of it, minimum changes of flow direction, smooth entry into turbo flange) and the limitations of the available space and turbo design (for example, I can’t angle the turbo flange as much as I’d like because the wastegate actuator bracket won’t go far enough round the CHA)
• My basic manifold design is 1.5” 304 Schedule 10 with a 2” to 1.5” reducer on the engine flange and the 2 runners going into a modified cast split T4 turbo flange. I've cut and welded the old steel manifold to place the turbo in position then built a wooden jig for manufacture.
• I’m looking to fit an EGT bung on each runner and am trying to leave the option of fitting connections for twin external wastegates just in case my IWG has problems.
• I’m looking at a downpipe of either 3” or 3.5” dependant on the exhaust bore. I’m having difficulty finding a nice routing for the downpipe to fit in the available space, allow room for a heatshield and minimize bends and area changes near the turbo. I’ll be fitting a bung for an AFR sensor (with heat spacer), although I’m unsure over how close to the turbo I can put it.

Fuel
• The 2 secondary injectors are Bosch 110R-000120 rated at 1700 cc/min (@43.5 psi) and the 2 primary injectors are Denso 1955-002460 rated at 550 cc/min. The [secondary] fuel rail is by Greddy.
• I’ve fitted a Walbro GSS342 pump and replaced the undersize cheap pipes, crass connections and Chinese pressure regulator fitted by The Bodger. The lines are now AN6.
• I’ve also modified the fuel pump basket and tank pipes to siphon fuel from the RH saddle, fitted foam baffling (as in the Aeromotive Stealth Phantom that I would have bought if one had fitted our short tank) to hopefully reduce fuel surge and, and fitted a fuel cooler in the return line (more for interest than actual need).
• I've not yet decided whether to have the pump at a constant 12v or use the RX8 PCM's 2-stage system (effectively switching in a resistor to reduce the pump voltage at lower RPM).

Gauges
• I horrified myself when I made a list of gauges to do the job properly: boost pressure, oil temperature, oil pressure, coolant temperature, AFR, fuel pressure, intercooler inlet and outlet temperatures, and [2 off] EGTs. And now someone’s recommended that I fit a turbo speed gauge. . . .
• Finding space for all the gauges is awkward, one reason to go for the Adaptronic ECU as I can use that to display gauge values on my tablet display. I bought a digital gauge for the oil and coolant temperatures that is small enough to fit in the instrument cluster. I have vent pod for the 2 most important gauges, probably AFR and turbo boost pressure.
• I’ll also be using some temporary gauges to assess the conversion’s performance, for example pressure losses in various parts of the system.

Gearbox
• I’m leaving the existing gearbox/transmission and clutch arrangement, a standard 6-speed with Exedy lightened flywheel and uprated clutch, until it goes bang.

Ignition
• I’m fitting 4 AEM coils.

Inlet manifold and throttle body
• If I stick with the cable-operated FD TB with Greddy elbow then I will make no changes.
• If I change, as I expect to, to an Adaptronic PNP with RX8 TB then I’m thinking of using a stripped, cleaned-up and shortened FD TB to free me up a bit of room whilst maintaining the efficient split of the air flow from the throttle body. whether justified or not, I implicitly don’t like using the inlet manifold to split the air between the 4 runners as in, for example, the Elite Rotary adaptor or simple spacer plates in other conversions.
• Also, if shortening the FD TB I’d also look to reduce the effective angle of the Greddy elbow and weld a cut-off RX8 TB flange to it.
• I’m planning on fitting an RX8 MAF ahead of the TB and haven’t yet decided on whether or not I will need an airflow-smoothing grid ahead of the MAF.

Interior (cabin)
• I’m thinking of fitting a set of quality front seats such as Brides or Recaros, but am waiting until a bargain appears, even if that means running the RX8 leather seats for a while – I’m finding it hard to justify the cost of new Brides and R3 interiors still go here IMO for silly money (over $1500).
• I will probably colour-co-ordinate the side panels and leather seat centres.

Steering
• I’m keeping the existing arrangement and have replaced the damaged steering unit (The Bodger fitted a rack with epoxy filler as one mounting bracket, undersize bolts, large nuts between the upper mounting points and frame and missing rubber spacers/mounts – no wonder the steering felt strange on track . . . ).
Structural
• I looked at stiffening the chassis to aid handling and decided to limit myself to the engine bay modifications discussed above and a rear strut brace.
Suspension
• When I was still trying hard to keep costs within perspective I fitted a used UK Prodrive (PZ) suspension. This lowers the car by 15mm/0.6” on stiffened springs and uprated shocks. I’m leaving that as it is.
• After evaluating the various ARB/sway bar options and what I remember of the handling on track I went for a Pettitt adjustable ARB/sway bar and aftermarket adjustable drop links on the front and the standard ARB with uprated rubber mounts on the rear.

Turbo
• I tossed and turned over the cost and specification of an EFR turbo (more expensive over here) in place of the Greddy TD07 I’d obtained to replace the original turbo (knackered Chinese copy rather than $2000 Turbonetics the previous owner and The Bodger both claimed). Then the opportunity came up to sell one of my kids for medical experiments so I ordered an EFR 7670 IWG, its response and power seeming better-suited to my needs than the EFR 8374.
• My only issue with the EFR 7670 is that I can’t rotate the turbine snail as much as I’d like to mate nicely with the exhaust manifold - the wastegate actuator bracket doesn’t go far enough around the CHA. I’ve not yet decided whether to compromise my manifold design or to produce a revised actuator bracket.

Turbo control (BOV, wastegates, boost control)
• I have the existing BOV and recently bought a boost controller and wastegates for my Greddy turbo. However, the 7670 IWG needs neither wastegates nor BOV and the Adaptronic has a boost control function. Once I’ve got my intended arrangement working I’ll sell on the unwanted items.
Turbo oil and water connections
• I’ve looked at the options I have for turbo oil and water connections. I’ll be using metal pipes near the turbo and flexible pipes to the engine connections.
• The Bodger bastardised my engine coolant supply casting so my arrangement will have to be slightly different to that of others here.
Underbody and engine protection
• I’ve fitted a 7mm Dural sump guard that I cut from a larger eBay one.
• Intuitively I’d like to plate most of the underside behind the engine bay to reduce drag. However, I have so far resisted the temptation as I’m concerned about cooling and heat retention.

Wheels
• I have 2 sets of wider wheels for road use (18” silver Oz Superlegera with 255/40/18 Goodyear Eagle F1 Asymmetric tyres and 19” Rota Grids with carbon-fibre vinyl wrap, painted rims and 255/35/19 Vredestein UltracSessanta tyres).
• I’ll keep the same size wheels and tyres on all 4 corners as I inherently don’t like staggered wheels.
• I have for a long time used for my standard RX8s sets of standard wheels with track tyres and winter tyres. However, these are probably unsuitable for this car and I’ll therefore look to get wider track tyres but not winter tyres.
• Although I’d like to keep both sets I’ll be short of storage room. I think I’ll have to make a choice between the 2 road sets based on how comfortable the 19” set is on the bad roads around here. If I use the 19” then I can use the 18” for track tyres.

Ian_D

Reserved for extra images and comment.

Brettus

iTrader: (2)

Now that's what I call a LIST !

Will be following with interest . Good luck !

I still say your turbo is too small for track duty and the the 8374 spools so well that there is no need to go smaller..........





7670 @ 14psi





8374@14psi

Ian_D

Thanks.

I know the 8374 will give me more power, something very useful on a track day. I accepted the 7670 as I was concerned about my ability on track where even a 7670 will give me twice the power that I have now, as much power that I'd be happy with (long story; I love track days but an injury restricts my ability).

Brettus

iTrader: (2)

My track ability is pretty average as well ...I just turn down the boost to keep me and the car happy . But even at lowish (12psi) boost it's pretty hard on the engine and drive train . Not nearly so hard if the turbo is running in it's sweet spot though.
The problem with the 7670 is that at any boost you run, at it's always going to be inefficient at high rpm.

Ian_D

I think the 7670 and 8374 are both compromises for a 13B REW, and initially I was sceptical of how good they would be. I've done a lot of work on jet engine compressors and turbines, even centrifugal ones (at one time I was the operational engineer for the servicing of all the RAF's fixed-wing centrifugal jet engines) so I thought the turbine and compressor were poorly matched for us.

However, I was swayed by the reports and dyno charts on the FD forums.

Compressor performance is only half the story though. There's also the turbo and the dance of rotor acceleration and deceleration, issues that I rarely see discussed, which is why I try to interpret them from what people and dyno charts say, albeit both are unreliable. That said, do you have the same compressor chart for the 8374?

Brettus

iTrader: (2)

I thought the 8374 was about perfect .... why do you see it as a compromise ?


Put it into my post above so you could see them side by side ..............

so 60ish% efficient vs 73% at redline . Works out to around 50degF at the compressor outlet and around 25whp extra .... for free .

dannobre

iTrader: (3)

Hell...the 9180 works and is a BEAST on a REW Think 600+ HP

Brettus

iTrader: (2)

Not everyone wants/needs that kind of power though . It's well before that level that major money needs to be spent on the driveline...........

Ian_D

Thanks for the maps. To sum up what they say, the 7670 is more efficient/better matched at lower power levels and the 8374 is more efficient/better matched at higher power levels.

My view on the effect of compressor efficiency is that we need to take it in perspective, where a 5% difference in efficiency typically results in only a 1% difference in horsepower. A quick back-of-the-***-packet calculation at a PR of 2.0 and an intercooler efficiency of 70% shows that a drop in compressor efficiency from 75% to 70% results in an intercooler exit temperature rise of 1.8C/3.3F and a horsepower loss of 0.6-0.8%.

As well as thinking that the EFR 7670 is better suited for the power levels I'm likely to use, I expect a lower risk of boost creep and heat build up.

Having said all of the above, if we're going to have any more discussion on these turbos can we move them to a separate thread so that others can find them more easily and they don't clog up my build thread?

Brettus

iTrader: (2)

I can't see the 7670 being efficient at ANY power level . It's always going to be around 60% no matter what boost you run because it is designed to suit a smaller engine running higher boost.
Add the lower turbine backpressure of the 8374 to the increased compressor efficiency and you get much happier engine at any power level.

Sorry for diverting the thread to where you didn't want to go . I'm sure the 7670 will perform well and you will be happy with the results. I just see the other turbo as a much better choice.

Ian_D

Thanks again for your advice & info. I'm busy until late Sunday when I'll start a thread to see what people think. I can add Firecran to the 8374 vote, so ignoring me that's 2-0 for the EFR 8374 . . .

If I wanted loads of power then I would certainly go for an 8374. I was looking for a useable street car and now I'm starting to feel the power bug. . . .

Brettus

iTrader: (2)

Make that 3-0 .
what size single turbo is best - RX7Club.com

Quote from the rx7 forum. Blue11 was one of the first to fit the 7670 , looks like he has seen the light .

Arca_ex

iTrader: (10)

You will have trouble keeping the boost down on the IWG 7670. You have three options, use expensive race gas, get bigger injectors and use E85, or you will have to use an auxiliary water/meth injection system.

The boost levels will probably creep too high on the IWG 7670 while still staying below the knock threshold of normal pump gas.

I would have gone for an IWG 8374 so the motor was less stressed and EGT's were lower but the build looks promising.

Ian_D

I've spent a few hours revisiting my Excel calculations and playing with Matchbot*. My conclusions haven't changed:
The 9180 is the most efficient EFR for the 13B REW.
The 7670 and 8374 are both undersize, are less efficient, spin up a little earlier and struggle at higher power levels.
For my car - a road car with occasional track day use (not racing!) where early spool and power delivery (say 350 rwhp at 6,000-6,500 rpm) are more important than outright power - the 7670 fits well enough, particularly as its smaller size make it easier to fit.

For other cars with different uses and/or priorities then the 8374 and 9180 may well be more suitable.

Looking around on the internet, here Turbosource/Turblown say:
"EFR 7670 T4 .92 ; 64LB max flow, 57mm inducer, and 70mm turbine wheel . This is the smallest EFR that will work on a 2 rotor and to make a comparison to other brands it would be considered a 5761. This is the ideal size for a peak power of 300 to 400rwhp for a street driven or autoX car . It can make 450+rwhp but this requires 20+ psi on the top end. This turbo packs the biggest punch of any of the turbochargers below 3k RPMS, and can make 400+ft lbs of torque between 4 and 5k rpms at 25+psi. If you intend to spend a lot of time past 6500rpms you should move up to the 8374 turbocharger. A typical setup for pump gas with a 3″ exhaust at 16 psi is shown to the right( 400rwhp)"
"Generally one should not use the EFR 8374 for power levels below 400rwhp where the EFR 7670 can outshine it. It is the ideal size for the 450 to 500rwhp"

*Update. I add some Matchbot maps at 16 psi (Points: 1 = 2000 rpm, 2 = 3,000 rpm, 3 = 4,000 rpm, 4 = 5,000 rpm, 5= 6,000 rpm, 6 = 7000 rpm).Ooops Images haven't kept my data points. I'll redo them soon. In the mean time, my points are very close to those put up by Brettus above.
These points are representative and will move around a little with different assumptions. My full Matchbot data points are 7670 8374 and 9180. By all means let me know if you think I can use better figures - I'm always interested to hear views on volumetric efficiency, bsfc, etc - preferably by opening a thread in the forum here or pm rather than clog up this thread.
I attach a dyno showing over 410 fwhp from an EFR 7670 on a 13B REW at 20 psi albeit with some loss of pressure at higher rpms due to, I believe, the wastegate spring not being strong enough (I imagine the real situation & cure are a little more complicated). My Matchbot plot for this is here.

JBalla1036

Wow that is some build list, can't wait to see the finished product!

Brettus

iTrader: (2)

mine were at 3000 through to 8000 ....

strokercharged95gt

+1, I may steal some of your ideas.