Did your engines blow up because you were pushing them hard on the autox course or was there something that could have been done to prevent it? Im considering going BT but I also autox my car and if its going to result in a high risk of blowing up on the course then maybe I dont want to.
GREAT question. Please read the whole response below: At this point I’m attributing both blowups to user error. The first one died because I was running a reputable off-the shelf tune (MonsterTuned Adapt-X), which specifically said NOT to mess with the wastegate whatsoever. I thought I’d get lucky and tightened my stock wastegate preload all the way down. Made the car noticeably faster, but I ignored the tune instructions and it overboosted and blew out Cyl4 ringlands when I took it to an autocross a week later. No wonder, lol. The second go around was also my fault…I went big turbo on stock fueling and a (supposedly) 75,000mile stock motor with no water/meth injection. I did carry over the full bolt-ons+ FMIC I was running on the stock turbo, but it wasn’t enough to keep me from LSPI’ing my motor on the freeway on the way home from another autocross event. I was cruising in 6th, downshifted to 4th to pass someone, goosed it, and heard the classic LSPI “fart of death” once I mashed the throttle. Same failure too: ringlands in Cyl4 went, low compression on #4. At the time of failure, I had made sure I was above 3000RPMs before matting it, and I was running the finalized pro tune, by none other than Alan at Edge Autosport himself (who I do not fault for this happening, he was fantastic). My fatal mistake on this car was not gapping ringlands/building the block up for longevity, or at least running WMI to protect the block from high boost/combustion temps. If I were to do it over, I’d have gone with the exact same setup I had before, but would have pre-gapped my rings and used a good-condition, low mileage motor, and I would 1000% run at LEAST water injection (without tuning for performance using it) to keep combustion temps/effective octane low and protect the block from LSPI. LSPI is a killer and CAN still get you, even if you think you know what you’re doing. Humans make mistakes. My $0.02. Also, for what it’s worth, I had ZERO engine problems when I was 100% stock (for the first and last 10,000mi I owned the car). After the second blowup I said hell with it and went back to totally stock, prepped the car for GS, and was WAY more successful autocrossing that setup than ever before. Like no joke, beating RS’s and Golf Rs in the WET. These cars are G-Street machines if you leave them stock. Stalk my channel for more of that content :) Cheers!
I noticed the same thing happened to both engines. You are stage 3, but you forgot a critical component. Your stock muffler is EXTREMELY restrictive and is causing back pressure. That excess pressure is collecting in your head under boost and is causing lift because of your stock head bolts. You need 2 things. First, a proper flow-through catback to relieve that pressure, and second, ARP head studs. Those two combined will keep the head clamped down on the block and prevent the head gasket from repeatedly blowing out. But you have to do AT LEAST the catback. If you do just the studs the pressure will either blow a ringland or the side of your block out.
While I appreciate this comment, it simply doesn’t apply to this situation. Both engines experienced ringland failures due to cylinder heat expanding the rings past their critical point of expansion and closing the gap on Cylinder 4 first due to the temperature gradient resulting from an uneven coolant channel flowing right next to it inside the block. The factory exhaust on these cars is only a restriction over 400-410whp according to my own research and personal experience. The theory is correct but at my power levels your comment simply is not true. I was never in danger of lifting the head at just 25psi of boost. These motors are known to handle twice that when built properly, but the weakness is always the bottom end. A built motor was prohibitively expensive so I ended up going completely back to stock and swapping a third motor in with mileage that matched my odometer. Been enjoying my trouble-free hot hatch ever since :)
The turbo flutter 🤤🤤🤤
Looks super fun
Did your engines blow up because you were pushing them hard on the autox course or was there something that could have been done to prevent it? Im considering going BT but I also autox my car and if its going to result in a high risk of blowing up on the course then maybe I dont want to.
GREAT question. Please read the whole response below:
At this point I’m attributing both blowups to user error. The first one died because I was running a reputable off-the shelf tune (MonsterTuned Adapt-X), which specifically said NOT to mess with the wastegate whatsoever. I thought I’d get lucky and tightened my stock wastegate preload all the way down. Made the car noticeably faster, but I ignored the tune instructions and it overboosted and blew out Cyl4 ringlands when I took it to an autocross a week later. No wonder, lol. The second go around was also my fault…I went big turbo on stock fueling and a (supposedly) 75,000mile stock motor with no water/meth injection. I did carry over the full bolt-ons+ FMIC I was running on the stock turbo, but it wasn’t enough to keep me from LSPI’ing my motor on the freeway on the way home from another autocross event. I was cruising in 6th, downshifted to 4th to pass someone, goosed it, and heard the classic LSPI “fart of death” once I mashed the throttle. Same failure too: ringlands in Cyl4 went, low compression on #4. At the time of failure, I had made sure I was above 3000RPMs before matting it, and I was running the finalized pro tune, by none other than Alan at Edge Autosport himself (who I do not fault for this happening, he was fantastic). My fatal mistake on this car was not gapping ringlands/building the block up for longevity, or at least running WMI to protect the block from high boost/combustion temps. If I were to do it over, I’d have gone with the exact same setup I had before, but would have pre-gapped my rings and used a good-condition, low mileage motor, and I would 1000% run at LEAST water injection (without tuning for performance using it) to keep combustion temps/effective octane low and protect the block from LSPI. LSPI is a killer and CAN still get you, even if you think you know what you’re doing. Humans make mistakes. My $0.02.
Also, for what it’s worth, I had ZERO engine problems when I was 100% stock (for the first and last 10,000mi I owned the car). After the second blowup I said hell with it and went back to totally stock, prepped the car for GS, and was WAY more successful autocrossing that setup than ever before. Like no joke, beating RS’s and Golf Rs in the WET. These cars are G-Street machines if you leave them stock. Stalk my channel for more of that content :)
Cheers!
I was there :P
I noticed the same thing happened to both engines. You are stage 3, but you forgot a critical component. Your stock muffler is EXTREMELY restrictive and is causing back pressure. That excess pressure is collecting in your head under boost and is causing lift because of your stock head bolts. You need 2 things. First, a proper flow-through catback to relieve that pressure, and second, ARP head studs. Those two combined will keep the head clamped down on the block and prevent the head gasket from repeatedly blowing out. But you have to do AT LEAST the catback. If you do just the studs the pressure will either blow a ringland or the side of your block out.
While I appreciate this comment, it simply doesn’t apply to this situation. Both engines experienced ringland failures due to cylinder heat expanding the rings past their critical point of expansion and closing the gap on Cylinder 4 first due to the temperature gradient resulting from an uneven coolant channel flowing right next to it inside the block. The factory exhaust on these cars is only a restriction over 400-410whp according to my own research and personal experience. The theory is correct but at my power levels your comment simply is not true. I was never in danger of lifting the head at just 25psi of boost. These motors are known to handle twice that when built properly, but the weakness is always the bottom end. A built motor was prohibitively expensive so I ended up going completely back to stock and swapping a third motor in with mileage that matched my odometer. Been enjoying my trouble-free hot hatch ever since :)