Pops and Bangs, and No Power
Discussion
Refitted the turbo finally, started it up and was fine, let it warm up a bit and fine, drove it a little and fine. Restarted it at the petrol station and it started popping and banging.
Thought the engine was going to explode skywards until I realised it's coming from the exhaust.
Can someone confirm that this means I have an air leak and that the pops and bangs are the result of overfuelling due to the O2 sensor going beserk? Checked all the obvious filters/air hoses/vac pipes and they all seem to be tied down fairly well. When it cooled a little the car seemed to clear it's throat and sounded fine again. Drive it a short distance and it returns.
Many Thanks.
Thought the engine was going to explode skywards until I realised it's coming from the exhaust.
Can someone confirm that this means I have an air leak and that the pops and bangs are the result of overfuelling due to the O2 sensor going beserk? Checked all the obvious filters/air hoses/vac pipes and they all seem to be tied down fairly well. When it cooled a little the car seemed to clear it's throat and sounded fine again. Drive it a short distance and it returns.
Many Thanks.
Sorry to keep bringing this one back from the dead, but does anybody have any more ideas?
I've refitted the turbo and the car is kind of back to life. I managed to get 0.5 bar out of it this evening but it was running 0.9 prior to replacement and it still runs quite roughly at revs up to about 3K. The engine coughed and choked a bit on startup but calmed down after about 30 seconds to a minute and now seems fine. I got a loud whistle under bost testing yesterday so tightened up the manifold bolts a touch more, and the whistle has now gone.
I'm not sure if I just need to keep tightening those bolts a fraction and I'll be back in business or if I've completely missed something stupid. My poor little hands and knuckles are red raw, I'm tired and grumpy but I really don't want to give up at this stage and send it to a garage for completion as I've put in so much effort - plus I've got a feeling it's got to be something relatively simple as it's so close to being my little baby again.
I've refitted the turbo and the car is kind of back to life. I managed to get 0.5 bar out of it this evening but it was running 0.9 prior to replacement and it still runs quite roughly at revs up to about 3K. The engine coughed and choked a bit on startup but calmed down after about 30 seconds to a minute and now seems fine. I got a loud whistle under bost testing yesterday so tightened up the manifold bolts a touch more, and the whistle has now gone.
I'm not sure if I just need to keep tightening those bolts a fraction and I'll be back in business or if I've completely missed something stupid. My poor little hands and knuckles are red raw, I'm tired and grumpy but I really don't want to give up at this stage and send it to a garage for completion as I've put in so much effort - plus I've got a feeling it's got to be something relatively simple as it's so close to being my little baby again.
gadgeroonie said:
you need to take it to somebody with a rolling road and some noble knowledge
where r you based ?
p.s - did you put the same preload on both actuators ?
does it have new actuator(s) ?
The refitted turbo is a replacement as my original was in pretty bad shape, but the actuator was set on the new item to what it was on the old (supposedly). I'm based between MK and Northampton.where r you based ?
p.s - did you put the same preload on both actuators ?
does it have new actuator(s) ?
When I talked about this with Turbo Technics they said the actuator on the old item was set at 0.45 bar. I was running the car at 0.9 bar previously and assumed .9 was what each turbo was set to, so Turbo Technics were fairly surprised when I asked them to set it to 0.9 (which we didn't in the end). Suspicious though that it seems to cut off at roughly 0.4-0.5 bar now...
Edited by NobleGuy on Tuesday 4th November 10:03
That has been my conclusion over the morning. When I spoke to TT they said at 0.9 bar the bearings 'Are not going to like it very much...' and I took their word for it. Beforehand I naturally assumed both turbos would be set at 0.9 bar so was surprised to be told that my old unit was set at 0.45 (the gauge on the car always showed 0.9 being achieved prior to removal).
Is the total boost the sum of the boost of the two turbos, or the average? My thinking is that with two manifolds the bar pressure will be the average of the two, not the sum and so each turbo should be set at .9.....
Sorry for all the potentially obvious rubbish I'm posting but I'm just trying to work out who's talking sense and if TT were just plain wrong.
Is the total boost the sum of the boost of the two turbos, or the average? My thinking is that with two manifolds the bar pressure will be the average of the two, not the sum and so each turbo should be set at .9.....
Sorry for all the potentially obvious rubbish I'm posting but I'm just trying to work out who's talking sense and if TT were just plain wrong.
The system works by using a boost solenoid to dump off excess pressure preventing the wastegates from opening early. If you don't have the electronic control, all the boost pressure is going into the wastegates and opening them at the pre-load. The pre-load for a 3 and 3R is 0.3Bar and for an M400 the pre-load is 0.5Bar. The electronic boost controller controls boost above that.
You should re-check your electrics. Then re-check the plumbing and the way that the boost solenoid is plumbed up with the hoses. Perhaps you could post a pic?
YellowShed
You should re-check your electrics. Then re-check the plumbing and the way that the boost solenoid is plumbed up with the hoses. Perhaps you could post a pic?
YellowShed
Martin,
You could do it but I don't know where the boost would go to - it's a duty cycle on the solenoid with a fairly weak PID so it would try and correct down to the mapped target but probably over-boost somewhat. The standard map should be safe for moderate over-boost (as the Vegantune over-boost buttons used to do that) but if you start to run around 0.9-0.95 bar over 5000rpm, there's a very good chance of causing problems (with the standard map and standard exhaust system). Don't forget, the turbos and camming are different on the 400s, for good reasons.
Some changes and a remap, and it'd be fine. Power increases could be up to 50bhp and 60lbft for the torque, depending on what else is fitted. We know that the clutch is good for a bit over 400lbft. The torque increase is definitely perceptible!!!!
YellowShed
You could do it but I don't know where the boost would go to - it's a duty cycle on the solenoid with a fairly weak PID so it would try and correct down to the mapped target but probably over-boost somewhat. The standard map should be safe for moderate over-boost (as the Vegantune over-boost buttons used to do that) but if you start to run around 0.9-0.95 bar over 5000rpm, there's a very good chance of causing problems (with the standard map and standard exhaust system). Don't forget, the turbos and camming are different on the 400s, for good reasons.
Some changes and a remap, and it'd be fine. Power increases could be up to 50bhp and 60lbft for the torque, depending on what else is fitted. We know that the clutch is good for a bit over 400lbft. The torque increase is definitely perceptible!!!!
YellowShed
YellowShed said:
Martin,
You could do it but I don't know where the boost would go to - it's a duty cycle on the solenoid with a fairly weak PID so it would try and correct down to the mapped target but probably over-boost somewhat. The standard map should be safe for moderate over-boost (as the Vegantune over-boost buttons used to do that) but if you start to run around 0.9-0.95 bar over 5000rpm, there's a very good chance of causing problems (with the standard map and standard exhaust system). Don't forget, the turbos and camming are different on the 400s, for good reasons.
Some changes and a remap, and it'd be fine. Power increases could be up to 50bhp and 60lbft for the torque, depending on what else is fitted. We know that the clutch is good for a bit over 400lbft. The torque increase is definitely perceptible!!!!
YellowShed
That's essentially what JNM did to mine in May and it really did feel that bit quicker. Gains were around 55bhp and 50lbft torque (15% increases).You could do it but I don't know where the boost would go to - it's a duty cycle on the solenoid with a fairly weak PID so it would try and correct down to the mapped target but probably over-boost somewhat. The standard map should be safe for moderate over-boost (as the Vegantune over-boost buttons used to do that) but if you start to run around 0.9-0.95 bar over 5000rpm, there's a very good chance of causing problems (with the standard map and standard exhaust system). Don't forget, the turbos and camming are different on the 400s, for good reasons.
Some changes and a remap, and it'd be fine. Power increases could be up to 50bhp and 60lbft for the torque, depending on what else is fitted. We know that the clutch is good for a bit over 400lbft. The torque increase is definitely perceptible!!!!
YellowShed
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