Rover with a turbo, or: How to build a reliable turbo track car. SPM S1, NASA ST3/4
#81
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I saw this happen in bike racing all the time. Cycling is considerably cheaper than motorsports, but folks would bust their *** at a day job (whatever it was) and try to fit in riding at other times. Now compare that to a pro that doesn't have to lift a finger during the day other than to get on a bike and pedal, and you can already see the discrepancy in terms of footing. If you're working at a pizza place or whatnot you're on your feet all day and you're trying to bike 300-400 miles a week and try to recover etc.
Then consider the fact that folks get hurt really really bad while racing or training sometimes. Your entire life basically crashes and you have nothing to fall back on. It's devastating. The smart folks get a degree in exercise physiology or nutrition or whatnot and race through college at a few places that can do it at a high level. They run and develop their business while trying to make things work (good help here... helps). They have a fallback.
There's a huge difference between spending your late teens/early 20's doing something that has legitimately no fallback.
Then consider the fact that folks get hurt really really bad while racing or training sometimes. Your entire life basically crashes and you have nothing to fall back on. It's devastating. The smart folks get a degree in exercise physiology or nutrition or whatnot and race through college at a few places that can do it at a high level. They run and develop their business while trying to make things work (good help here... helps). They have a fallback.
There's a huge difference between spending your late teens/early 20's doing something that has legitimately no fallback.
#82
back on topic - there is some excellent wheelin going on there by Andrew - and there is a YUGE amount of knowledge evident in the stability of the car in braking, turn in, and corner exit, not to mention putting down 195 whp reliably, with a great turbo kit and relatively stock engine - mostly developed by he, Emilio, and a few others over the past 10 years.
#84
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Had a successful weekend with NASA at Sonoma. Two ST4 wins and two TT4 wins in blistering heat. I'll post some video later today.
Rover is classed into ST4 at 215whp/2473lbs, average power of 211.25whp. Big fat powerband.
Full specs:
1994 BP05 longblock
Stock 9:1 83mm BP05 pistons
Manley rods
ACL Race bearings
ARP head/main studs
OEM Mazda 01+ oil pump
Supermiata Harmonic Damper
Stock BP05 as-cast cylinder head
Supertech heavy doubles + titanium retainers + BP4W valve locks
stock BP05 HLAs, stock cams
stock BP05 intake manifold
Skunk2 TB
Trackspeed EFR6258 turbo system, 10psi boost
Pre-production Trackspeed FMIC kit w/ Precision 350hp core
open 3" exhaust (no mufflers/resonators)
MSLabs MS3 Basic, NB cam/crank sensors
FlowForce EV14 640cc injectors
Deatschwerks DW200
OEM 01-05 coils
CA91 pump gas
Rover is classed into ST4 at 215whp/2473lbs, average power of 211.25whp. Big fat powerband.
Full specs:
1994 BP05 longblock
Stock 9:1 83mm BP05 pistons
Manley rods
ACL Race bearings
ARP head/main studs
OEM Mazda 01+ oil pump
Supermiata Harmonic Damper
Stock BP05 as-cast cylinder head
Supertech heavy doubles + titanium retainers + BP4W valve locks
stock BP05 HLAs, stock cams
stock BP05 intake manifold
Skunk2 TB
Trackspeed EFR6258 turbo system, 10psi boost
Pre-production Trackspeed FMIC kit w/ Precision 350hp core
open 3" exhaust (no mufflers/resonators)
MSLabs MS3 Basic, NB cam/crank sensors
FlowForce EV14 640cc injectors
Deatschwerks DW200
OEM 01-05 coils
CA91 pump gas
#88
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The spark map is the MSLabs base map for 94-95, IIRC. It's 17deg advance at torque peak, 19deg at max power from the datalog.
BP4W cam cover/intake cam gear, VVT coils. I have a bracket for the coils but I'm not happy with it. I could also do an MSM valve cover. The VVT coils were already wired in from the last few motors and I didn't want to hassle with replacing them since I knew they would be perfectly adequate for the project goals.
BP4W cam cover/intake cam gear, VVT coils. I have a bracket for the coils but I'm not happy with it. I could also do an MSM valve cover. The VVT coils were already wired in from the last few motors and I didn't want to hassle with replacing them since I knew they would be perfectly adequate for the project goals.
#96
Megasquirt falls into that category. An owner can build one from scratch, buy a DIY PNP2 or 3 or MSlabs. Again, proven, reliable, cheap. Also makes it easier for us to police maps should the need arise as the series goes national.
But yah, set of Hoosiers, high boost map and the S1 owner is flirting with some very fast company.
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#99
There is a long list of single item mods to S1 rules to make them faster. We focused on the top of the bell curve for ease of build and setup, cost and reliability. No unknowns, just whats is proven and conservative.
Megasquirt falls into that category. An owner can build one from scratch, buy a DIY PNP2 or 3 or MSlabs. Again, proven, reliable, cheap. Also makes it easier for us to police maps should the need arise as the series goes national.
But yah, set of Hoosiers, high boost map and the S1 owner is flirting with some very fast company.
Megasquirt falls into that category. An owner can build one from scratch, buy a DIY PNP2 or 3 or MSlabs. Again, proven, reliable, cheap. Also makes it easier for us to police maps should the need arise as the series goes national.
But yah, set of Hoosiers, high boost map and the S1 owner is flirting with some very fast company.
I think building towards an S1 setup but with the twin scroll hot side parts is in the future. I already have the aero package sitting here. With the new BMW transmission swap that everyone is getting excited about it would be completely capable of running in ST2, ST3, ST4, and maybe even ST5 depending on how that class falls.
Anyways, on with the thread, I like where this is going and will be fun to watch some S1 races once some more get built.
#100
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Proper TS manifold requires looping cyl2 and 3 on top of each other, so no cast manifold in existence will do it. You are limited to tubular and all of the reliability woes that come with it.
Then you have more exh. manifold volume than a TSE T25 manifold. More volume means more time to fill and pressure and less response.
Then you are limited to a 0.80a/r turbine housing which means less response again. The twinscroll benefit is primarily at lower RPM where the pulses can be adequately separated and used more efficiently. At higher RPM they end up on top of one another no matter what, and the effect diminishes substantially. In a race car, the net result of this is making the turbine housing needlessly larger. If the turbine housing were an 0.64a/r TS, then you might see some low-end gains, but the manifold will still be worse. I have seen multiple 400whp EFR6758 setups blowing through this manifold and this turbine housing, so there's no evidence to suggest that the 0.64a/r turbine housing is restrictive enough to warrant upsizing, especially at S1 or ST4 power levels (or even at ST3 power levels, ~250-260whp). I have also seen some pretty poor-performing 0.85a/r EFR B1 setups which point to the same conclusion.
I went with low-volume and single-scroll with low area ratios for a reason. Loopy manifolds and twin-scroll are sexy, but at our power levels, they just don't make sense.