Pat's Ebay Turbo Compound Boost Build
03-03-2016, 12:35 AM
#661
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Pics of subframe crack. Other side was not nearly as bad, but it was cracked too. I fixed both sides.
It cracked on this part, which is where the LCA puts it in tension when you accelerate. Probably cracked from wheel hoping drag radials on a prepped track, and power.
It cracked on this part, which is where the LCA puts it in tension when you accelerate. Probably cracked from wheel hoping drag radials on a prepped track, and power.
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03-04-2016, 12:31 AM
#666
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Got the sound deadening in the tunnels/trunk floor back in. Fixed bleed hole in boost controller for rear turbo, few other little things. Car is crazy quiet now, quieter than stock by a lot. Quieter exhaust, quieter road noise. And no more stinky exhaust with the cat hooked up. Street car life so nice.
Still working on getting the boost up, made a few pulls earlier and got it to 28, then gave it two more turns but not sure what that is yet, will find out tomorrow. SHOULD be able to go a lot higher on the boost than before I think with the smaller bleed hole in the gate. If for some reason it still maxes out at 32, I'll be putting a lot more spring in the rear gate. But I expect to be able to get a lot more than 32 out of the rear gate now. Will find out tomorrow.
Still working on getting the boost up, made a few pulls earlier and got it to 28, then gave it two more turns but not sure what that is yet, will find out tomorrow. SHOULD be able to go a lot higher on the boost than before I think with the smaller bleed hole in the gate. If for some reason it still maxes out at 32, I'll be putting a lot more spring in the rear gate. But I expect to be able to get a lot more than 32 out of the rear gate now. Will find out tomorrow.
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03-04-2016, 12:37 PM
#669
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Last time I was there I beat 3 out of 4 drag cars. The first two both put them on the trailer and didn't race again! Both of them beat me out of the hole, and I FLEW by them on the big end.
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03-04-2016, 12:42 PM
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What's funny is pretty much every person that looks under the hood sees the tiny turbo and thinks that's it. Probably 98% of people I told it was a compound turbo setup didn't know there was another, bigger turbo on the car even after looking at the engine bay.
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03-06-2016, 12:15 PM
#677
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It has 650 or so miles on it so far. Here's what's failed/changed so far.
The rear turbo oiled on shutdown by my original design. I ended up chainging the drain and adding a time delay to the scavenger pump to fix that.
Rear wastegate fell apart (3 bolts vibrated loose due to bad assembly from factory). I reassembled it and made sure those fasteners will never come out again.
Axle broke racing on a prepped track. In their defense they've seen A LOT of hell before this compound setup was built. I race this car every weekend and those axles have been in the car for a WHILE....
Subframe cracked. It was cracked before the compound setup was built, I just recently fixed it. I'm sure hard launches and wheel hop did it in.
In summary, the rear turbo oiling was my ignorance, having never designed a rear mount turbo I did not setup the drain correctly. The wastegate failure was a cheap part problem, and the axle/subframe are failures from racing the car every weekend for years. If I drove it on the street on street tires and never raced it, those would never have broken, but what's the point of building a fast car and not enjoying it?
Considering I designed/fabbed probably 100 different things on this compound turbo setup, and I've only had one failure directly related to my design/fabrication skills after 650 street miles and tracking it twice, I'm happy with that. The fact that everything else is working as designed without problems is awesome, that means I got most of it right from the beginning.
Also added a shift light and some warning lights, will try to take pics of those next time I have the laptop hooked up to the car. Also going to order a MBC for the rear turbo to help it spool better, just realized I never put a MBC on the rear gate....
The rear turbo oiled on shutdown by my original design. I ended up chainging the drain and adding a time delay to the scavenger pump to fix that.
Rear wastegate fell apart (3 bolts vibrated loose due to bad assembly from factory). I reassembled it and made sure those fasteners will never come out again.
Axle broke racing on a prepped track. In their defense they've seen A LOT of hell before this compound setup was built. I race this car every weekend and those axles have been in the car for a WHILE....
Subframe cracked. It was cracked before the compound setup was built, I just recently fixed it. I'm sure hard launches and wheel hop did it in.
In summary, the rear turbo oiling was my ignorance, having never designed a rear mount turbo I did not setup the drain correctly. The wastegate failure was a cheap part problem, and the axle/subframe are failures from racing the car every weekend for years. If I drove it on the street on street tires and never raced it, those would never have broken, but what's the point of building a fast car and not enjoying it?
Considering I designed/fabbed probably 100 different things on this compound turbo setup, and I've only had one failure directly related to my design/fabrication skills after 650 street miles and tracking it twice, I'm happy with that. The fact that everything else is working as designed without problems is awesome, that means I got most of it right from the beginning.
Also added a shift light and some warning lights, will try to take pics of those next time I have the laptop hooked up to the car. Also going to order a MBC for the rear turbo to help it spool better, just realized I never put a MBC on the rear gate....
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03-06-2016, 07:44 PM
#678
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Reliable 500hp Miata was the goal stated at the beginning of this thread. That's cool.
I've got confidence. Probably going to break some more **** before he gets it just right. Take Pat's car to the street as a DD/ fun car and I bet he's damn near there. Use it the toughest way possible like it's being used and it's already ******* amazing. And some things go from "breaking" to consumables.
I've got confidence. Probably going to break some more **** before he gets it just right. Take Pat's car to the street as a DD/ fun car and I bet he's damn near there. Use it the toughest way possible like it's being used and it's already ******* amazing. And some things go from "breaking" to consumables.
Last edited by fivehundredton; 03-06-2016 at 08:10 PM.
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03-06-2016, 09:20 PM
#679
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Reliable 500hp Miata was the goal stated at the beginning of this thread. That's cool.
I've got confidence. Probably going to break some more **** before he gets it just right. Take Pat's car to the street as a DD/ fun car and I bet he's damn near there. Use it the toughest way possible like it's being used and it's already ******* amazing. And some things go from "breaking" to consumables.
I've got confidence. Probably going to break some more **** before he gets it just right. Take Pat's car to the street as a DD/ fun car and I bet he's damn near there. Use it the toughest way possible like it's being used and it's already ******* amazing. And some things go from "breaking" to consumables.
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03-07-2016, 12:46 AM
#680
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Car now has a blow through miata MAF sensor between the intercooler and the throttle body. 
That sucked but it's done. Just tested and it works.
Gotta make a new EGR pipe still, and a fancy controller for fuel injectors to be controlled by stock ecu when not in boost.
That sucked but it's done. Just tested and it works. Gotta make a new EGR pipe still, and a fancy controller for fuel injectors to be controlled by stock ecu when not in boost.
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