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Feck me! (Unexpected BPU)


AlexM

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I did another test, hit 1.4bar then lost power (with a little ! on the dash). Lots of fun but I'd better behave, not quite ready to go single yet.

 

Checked with the Garage and they didn't check for a RR as my car was already decatted, find it a little crazy that it can run 0.9bar on a Stock exhaust and 1.4+ on a Tanabe! Can there really be that much difference in flow?

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Increase in power... yes. But where does the increase in boost come from? I'm a logical guy at heart so I like to understand things before I accept them. People always bang on about the boost increases in the winter but I can't fathom why.

 

As yourself and Gaz have said.... that is exactly how I understand it.

 

i think its the boost controller spiking for a fraction of a second.my hks boost controller is set to 1.4 but yet the highest reading which it holds automatically is 1.6. they do seem to make a little more power in cold weather maybe 10/15 hp in my opinion

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IS it a JSpec Alex??

 

Remember when in Germany and we took IanIan's, downpipe off coz it was leaking. The RR was what was causing the leak as it had disintegrated so we took it out completly put some gasket sealent on it and fitted it back together. Ian does not run a boost controller and he did not see anymore boost with no RR (even when the Nums fixed the other issue) and to my knowledge has not in this country in the colder weather.

 

I would tend to agree with the boost controller spiking and the additional power being down to the colder intake temps.

 

Before Ryan set up my Boost controller it used to spike too 1.35 bar for a fraction of a second on full boost when I was at BPU. Prob why my Jspec turbos fell apart when I took them off.

 

If you not BPU now then I dont get the point of the boost controller? Best advise would be to get a sized RR for 1 bar and turn all the boost controller off so the car is restricted to 1 bar on its own, then use the Boost controller to up the boost to 1.1 and 1.2 bar when required.

Edited by T2 MSW (see edit history)
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I've got plans to go BPU before the summer, but I keep reading that I should have a AFR gauge, which is a bit off-putting for me. I hate the idea of having multiple gauges. I'm fine with a boost gauge in the clock space, but I don't want another gauge just thrown in the car somewhere :(.

 

An AFR guage is a great indication of whats going on with the combustion but I did not have one in my car when I was BPU. If I did it again I would have an AFR guage over a boost guage though and monitor the boost from the Boost controler.

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An AFR guage is a great indication of whats going on with the combustion but I did not have one in my car when I was BPU. If I did it again I would have an AFR guage over a boost guage though and monitor the boost from the Boost controler.

 

:iagree:

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An AFR guage is a great indication of whats going on with the combustion but I did not have one in my car when I was BPU. If I did it again I would have an AFR guage over a boost guage though and monitor the boost from the Boost controler.

 

Thanks for the post.

 

I know a lot of people with BPU'd Supras don't have them, but when I go to BPU, I'd want one so I can keep an eye on what's happening. But actually having both would do my head in.

 

I like the idea of monitoring the boost pressure on the controller though.

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Thanks for the post.

 

I know a lot of people with BPU'd Supras don't have them, but when I go to BPU, I'd want one so I can keep an eye on what's happening. But actually having both would do my head in.

 

I like the idea of monitoring the boost pressure on the controller though.

 

Going a bit off topic but I wanted the boost guage as I wanted to use the controller to have a hi and Low boost setting. But in all honesty for the amount of times I switched between the two it was a waste, it was always on the lower setting.

 

I did the same thing when I went single had two settings and its always been on the lower setting untill I discovered 1.5 bar of boost :D

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Be very careful Alex. When CW fucked up my exhaust / restrictor ring set up my engine went bang when the boost spiked.

 

That was the start of all my ballache!

 

Not wanting to get into that at all, but on a side note;

 

Just wondering, I read that BPU is very reliable, but have there been a lot of problems on Supras when they initially go BPU then?

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Going a bit off topic but I wanted the boost guage as I wanted to use the controller to have a hi and Low boost setting. But in all honesty for the amount of times I switched between the two it was a waste, it was always on the lower setting.

 

I did the same thing when I went single had two settings and its always been on the lower setting untill I discovered 1.5 bar of boost :D

 

Fair point.

 

...and here we go... single talk again!:D Damn!

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Fair point.

 

...and here we go... single talk again!:D Damn!

 

wont bore you with that, only advise would be when your looking at components for BPU consider that at a later stage you *may* want to go to hybrids/small single so spec it for that not for BPU like I did or it will end up costing you twice for things like intercoolers, oil coolers etc.

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I don't have a boost controller yet Mike. The car is BPU, but was only running stock boost before I changed the exhaust.

 

I'm after a Blitz SBC i-Color, then the wideband AFR sensor.. though for now I've just ordered a RR from CW. :)

 

Ah ok fair enough, is it Jspec or UK? Assume if its overspooling it must be J-Spec.

 

Get yourself a 1 bar restrictor ring in there then and then you can put the Blitz SBC in there when you want to move to 1.2 bar and use that to up the boost.

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wont bore you with that, only advise would be when your looking at components for BPU consider that at a later stage you *may* want to go to hybrids/small single so spec it for that not for BPU like I did or it will end up costing you twice for things like intercoolers, oil coolers etc.

 

Very good point, thanks.

 

I will spend money on quality parts, which is why I probably wont go BPU for a while - I'm kind of hoping that BPU will be enough however, I'm not sure I could deal with the costs involved if a single set-up was to go wrong.

 

Besides, I know what an aerotop drives like on just standard TT, I can imagine it's a bit rubbish and very unsettling with BPU, but on a single... hm...

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Sorry to hijack a thread but since its sort of the topic anyway- I have a single decat (second cat at the rear is still in the car) with a 3" exhaust and mine only boosts to .9 bar- does this mean I have a restrictor ring in it or is it just the second cat doing the restriction ?

 

The 1st cat is very restrictive (the most restrictive of the 2), just removing the 2nd cat will hardly effect the boost.

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Very good point, thanks.

 

I will spend money on quality parts, which is why I probably wont go BPU for a while - I'm kind of hoping that BPU will be enough however, I'm not sure I could deal with the costs involved if a single set-up was to go wrong.

 

Besides, I know what an aerotop drives like on just standard TT, I can imagine it's a bit rubbish and very unsettling with BPU, but on a single... hm...

 

Its worth just considering, I wish I had when I had to buy my FMIC again as the one for BPU was not up to the job.

 

I had an aerotop NA and with the roof on and a decent geo setup its was cool. Roof off is a whole new ball game :)

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