Rover with a turbo, or: How to build a reliable turbo track car. SPM S1, NASA ST3/4
#161
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... was able to capture a fairly clean 1:39.4 in full S1 trim. 215whp, 2400lbs, 245/40 Maxxis RC-1s. Stinking fast given the setup. With the holdups in 5 and 11 I'm certain there's a 1:38.9x in the car. The entry speed into T6 scared me so bad I instinctively lifted. ![Party Kitty](https://www.miataturbo.net/images/smilies/birthday[1].gif)
The car ran all weekend with only a couple minor hiccups. I gave a bunch of rides, typically lapping in the 1:41-1:42 range
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The car ran all weekend with only a couple minor hiccups. I gave a bunch of rides, typically lapping in the 1:41-1:42 range
That was a lot of steering input for 6, I saw your cheeks clench through the screen.
I was rolling 4th through 7/8 because of that weird mid-turn upshift.
That is one hell of a lap for a 100% SPM S1 setup. /clap
I was never able to dip sub 40, but had several 39s on predicted. We had the wick turned up a bit and the Hoosiers from ~2013
#162
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After Thunderhill, I added a 13" SPAL curved-blade to replace the 8" eBay fan left over from the naturally aspirated days. The fully sealed ducting and 3000cfm of fan kept everything in check, even in 90-95*F weather. I was able to run full pace for the entire 30 minute race on Saturday.
#163
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First event of the year at Buttonwillow this weekend. Sunny and high 50s both mornings, magic lap weather. Brought some sticker 245/40 R7s and tried to become the 3rd Miata under the 1:50 mark, and the first to do it with less than 250whp.
So close. Sigh.
So close. Sigh.
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Nothing to report. Car is boringly reliable. Including MRLS in September and Chuckwalla 2 weeks ago, I've done 4 full weekends with nothing but basic maintenance.
Broke an axle at CVR. Apparently OEM axleshafts do not appreciate 2nd gear clutchdumps (trying to heat the tires before standing start). Noted.![Party Kitty](https://www.miataturbo.net/images/smilies/birthday[1].gif)
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One of the S2 cars at CVR had a subframe failure so I decided to get off my *** and add the Mazdacomp braces before spending the day at WSIR this weekend. I was debating pulling the control arm to keep heat out of the bushings, but I didn't have time to realign the car before the event, so I sprayed and prayed. No immediate indication that any damage was done, which is nice. Doing an overdue oil change while it's in the air too. It will need brakes after WSIR.
Broke an axle at CVR. Apparently OEM axleshafts do not appreciate 2nd gear clutchdumps (trying to heat the tires before standing start). Noted.
![Party Kitty](https://www.miataturbo.net/images/smilies/birthday[1].gif)
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One of the S2 cars at CVR had a subframe failure so I decided to get off my *** and add the Mazdacomp braces before spending the day at WSIR this weekend. I was debating pulling the control arm to keep heat out of the bushings, but I didn't have time to realign the car before the event, so I sprayed and prayed. No immediate indication that any damage was done, which is nice. Doing an overdue oil change while it's in the air too. It will need brakes after WSIR.
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#166
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One of the S2 cars at CVR had a subframe failure so I decided to get off my *** and add the Mazdacomp braces before spending the day at WSIR this weekend. I was debating pulling the control arm to keep heat out of the bushings, but I didn't have time to realign the car before the event, so I sprayed and prayed. No immediate indication that any damage was done, which is nice. Doing an overdue oil change while it's in the air too. It will need brakes after WSIR.
![](https://i.imgur.com/SipyekNh.jpg?)
#167
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Nothing to report. Car is boringly reliable. Including MRLS in September and Chuckwalla 2 weeks ago, I've done 4 full weekends with nothing but basic maintenance.
Broke an axle at CVR. Apparently OEM axleshafts do not appreciate 2nd gear clutchdumps (trying to heat the tires before standing start). Noted.![Party Kitty](https://www.miataturbo.net/images/smilies/birthday[1].gif)
Broke an axle at CVR. Apparently OEM axleshafts do not appreciate 2nd gear clutchdumps (trying to heat the tires before standing start). Noted.
![Party Kitty](https://www.miataturbo.net/images/smilies/birthday[1].gif)
One of the S2 cars at CVR had a subframe failure so I decided to get off my *** and add the Mazdacomp braces before spending the day at WSIR this weekend. I was debating pulling the control arm to keep heat out of the bushings, but I didn't have time to realign the car before the event, so I sprayed and prayed. No immediate indication that any damage was done, which is nice.
#168
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Probably. I found a torn CV boot on the other axle (the one I didn't replace at CVR) so I'm just going to spring for the DSS axles w/ vented boots.
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Balancing guibo started to come loose at WSIR and came fully loose at LVMS a few weeks ago. I thought it was the driveshaft but found the guibo loose when I went to change it this week. Did rear pads/rotors, front pads, and gave everything else a once over.
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Took it to Sonoma yesterday for an open test day to tweak on the chassis a bit, but mostly to just fool around on my favorite race track and try out the new trailer.
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Tweaked the balance on some decent RC1s, then bolted up some 2-cycle 245 R7s.
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Took it to Sonoma yesterday for an open test day to tweak on the chassis a bit, but mostly to just fool around on my favorite race track and try out the new trailer.
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Tweaked the balance on some decent RC1s, then bolted up some 2-cycle 245 R7s.
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Had a great time at MRLS. Decided not to drive this year so I could spend more time hanging out with folks.
We did finally encounter a new issue with Rover which is getting cleaned up this week. It's been a very long time since I've run HLAs, and I didn't think about how much heavier they were than an OE NB lifter. The HLAs combined with the semi-budget nature of the engine in Rover led to a new discovery for me. Turns out that a Supertech single spring is not enough to control a factory valve and factory HLA anywhere past 7000rpm, even just to 7400. I have been running the high-limit map for a couple of events, but after MRLS it sounded like it was trying to start up on 3 cylinders, and a leakdown revealed intake valve damage on #1 and #2. Going to convert to ST doubles and NB lifters, which should cure it.
Looks like a crime scene in the shop. Rushing to get it done before Sonoma this weekend.
We did finally encounter a new issue with Rover which is getting cleaned up this week. It's been a very long time since I've run HLAs, and I didn't think about how much heavier they were than an OE NB lifter. The HLAs combined with the semi-budget nature of the engine in Rover led to a new discovery for me. Turns out that a Supertech single spring is not enough to control a factory valve and factory HLA anywhere past 7000rpm, even just to 7400. I have been running the high-limit map for a couple of events, but after MRLS it sounded like it was trying to start up on 3 cylinders, and a leakdown revealed intake valve damage on #1 and #2. Going to convert to ST doubles and NB lifters, which should cure it.
Looks like a crime scene in the shop. Rushing to get it done before Sonoma this weekend.
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Ran great at Sonoma with the fresh head. My dad came up for both days and we did dual sessions the entire weekend. I need to get back to a dyno to touch up my S1 maps since I am clearly down on power to Emilio, but I did manage to block my way to a race win on Sunday anyway. Only issue was a self-induced wheel bearing failure. I caught the front edge of the entry curb in T2 during race 1 on Sunday which wrecked the bearing, and it failed completely entering T11 on the final lap of race 2. Still got the win, though.
A little break for me, then off to Chuckwalla for the season finale in November. CVR is always a good time.
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A little break for me, then off to Chuckwalla for the season finale in November. CVR is always a good time.
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My race video is boring. I spent all day Sunday blocking Emilio, but I don't have a rear-facing cam, so it just looks like I selectively forgot what a proper racing line is. I'll link to his race video when he posts it.
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Winter is upon us, I had to go find my sweatshirt.
I am making some big upgrades to the safety gear suite on Rover. Cage upgrades, new solid-state kill switch to adhere to the Supermiata two-position rule for 2019, and a new electronic/automatic fire system. Car is at TC right now getting the cage updates, which I am most excited about, but text is boring and pictures are sexy so I'll post more on those updates when it returns.
I went with Cartek's solid-state switch for the battery cut-off. It uses a pair of momentary buttons, one as an on-off and one (or more) as momentary triggers. When any of the buttons are pressed, it interrupts the ground path between the battery and the chassis. It also interrupts +12v to either the coils or ECU or anything else, depending on how it's installed. Rather than having 4-gauge battery cable strung all over the car, I'll be able to mount this guy right next to the battery and just have small buttons. It also prevents the scenario where the external kill switch is left off, and you've belted yourself into the car, since even after the external switch has been tripped, the internal switch can re-activate everything again.
I will do the main on-off button at the center console, with the secondary button at the driver's A-pillar, mounted on the cage facing outwards.
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Fire system will likely be SPA's FIA-spec electrical/automatic system. Big 8mm Decabon tubing and only 4 nozzles, compared to my existing system which is 6mm tubing and 6 nozzles. Two nozzles will go inside the car and fire perpendicular to direction of travel just ahead of the shifter. Two more will go in the engine bay, one aimed at the turbo/dipstick area and one aimed at the fuel rail/injectors.
I am swapping SPA's trigger buttons for Cartek's dual-purpose buttons as well - Cartek makes a momentary button that's designed to trigger an automatic extinguisher system and the battery switch at the same time.
![Party Kitty](https://www.miataturbo.net/images/smilies/birthday[1].gif)
I am making some big upgrades to the safety gear suite on Rover. Cage upgrades, new solid-state kill switch to adhere to the Supermiata two-position rule for 2019, and a new electronic/automatic fire system. Car is at TC right now getting the cage updates, which I am most excited about, but text is boring and pictures are sexy so I'll post more on those updates when it returns.
I went with Cartek's solid-state switch for the battery cut-off. It uses a pair of momentary buttons, one as an on-off and one (or more) as momentary triggers. When any of the buttons are pressed, it interrupts the ground path between the battery and the chassis. It also interrupts +12v to either the coils or ECU or anything else, depending on how it's installed. Rather than having 4-gauge battery cable strung all over the car, I'll be able to mount this guy right next to the battery and just have small buttons. It also prevents the scenario where the external kill switch is left off, and you've belted yourself into the car, since even after the external switch has been tripped, the internal switch can re-activate everything again.
I will do the main on-off button at the center console, with the secondary button at the driver's A-pillar, mounted on the cage facing outwards.
![Name: z1zhcKP.jpg
Views: 68
Size: 40.9 KB](https://www.miataturbo.net/attachments/build-threads-57/230481d1683052353-rover-turbo-how-build-reliable-turbo-track-car-spm-s1-nasa-st3-4-z1zhckp.jpg)
Fire system will likely be SPA's FIA-spec electrical/automatic system. Big 8mm Decabon tubing and only 4 nozzles, compared to my existing system which is 6mm tubing and 6 nozzles. Two nozzles will go inside the car and fire perpendicular to direction of travel just ahead of the shifter. Two more will go in the engine bay, one aimed at the turbo/dipstick area and one aimed at the fuel rail/injectors.
I am swapping SPA's trigger buttons for Cartek's dual-purpose buttons as well - Cartek makes a momentary button that's designed to trigger an automatic extinguisher system and the battery switch at the same time.