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MS-75 Regular Location: Adelaide Registered: June 2002	Re: 1JZ-GTE not boosting? Wed, 18 June 2003 23:36 Just to clarify the issue as to wether particles can make their way from the exhaust into the cyls, in short-yes it is quite possible-especially on later model EFI motors. To explain- On trailing throttle with the butterfly closed, you have max engine vacuum. The sequence is Intake valve opens, piston travels down the bore. As the throttle is closed, very little air passes into the cyl. (man vac usually over 25 inches of Hg) Note also that if an efi vehicle uses deceleration fuel cut off, no fuel will be injected at this point. Intake valve closes, piston travels up the bore. As there very little air in the cyl in the first place, no pressure is generated (in-fact at the top of the compression stroke the pressure is equivalent to the vacuum in the manifold.) Power stroke-piston travels down bore-(remember that there is full vacuum at the start of the power stroke) There is NO combustion, and so at the completion of the stroke (bottom dead centre or so) the vacuum is still present. The exhaust valve opens, and air in the exhaust manifold RUSHES INTO THE CYLINDER, carrying with it bits of crap from the exhaust manifold. As the piston travels back up the cylinder the air is shoved back out again. This sequence is repeated whilst the car is on trailing throttle with decel cut-off. Also consider the shape of the turbo, and that is that the shattered bits of the exhaust wheel will be sitting in the outside of the snail as when the explosion occurs the bits are flung outward by centrifugal force-and are not blown out the back of the blower. (they will eventually al get blown out but, but some may remain-waiting to be sucked back into the cylinder. This explains why the cyls associated with the turbo are damaged.) Also consider that when a turbo blows-what do you do? You get off the gas pretty quickly……… The shape of the turbo manifold can also make the path of debris easier-and the 1JZ manifold being stubbly and mid mount with the blowers very close to the cyls is a case in point. Long runner style manifolds make this scenario less likely, as do low-mount manifolds like those on the RB 30. Also, with regard to the 0 psi-when the car was 'boosting', the damaged blower would have been flowing air OUT the intake. As I have said before a vehicle with decel fuel cut off is most likely to experience the above scenario. In this particular case I'm unsure of how the blower was blown to begin with-most likely it was buggered when it was installed into the car. If it didn't boost up the first instant it was driven, the blower was probably already damaged. Condolences mate. Go get them tiger. That really sucks. Sean Adelaide [Report message to a moderator]

	Subject	Poster	Date
	1JZ-GTE not boosting?	SkiDMaN	Mon, 09 June 2003 11:35
	Re: 1JZ-GTE not boosting?	Norbie	Tue, 10 June 2003 01:51
	Re: 1JZ-GTE not boosting?	MR. 2	Tue, 10 June 2003 03:00
	Re: 1JZ-GTE not boosting?	SkiDMaN	Tue, 10 June 2003 09:04
	Re: 1JZ-GTE not boosting?	SUPRAGTE	Tue, 10 June 2003 09:23
	Re: 1JZ-GTE not boosting?	manipulate	Tue, 10 June 2003 09:46
	Re: 1JZ-GTE not boosting?	Norbie	Tue, 10 June 2003 13:52
	Re: 1JZ-GTE not boosting?	wastegate	Tue, 10 June 2003 14:11
	Re: 1JZ-GTE not boosting?	Remedy	Tue, 10 June 2003 14:19
	Re: 1JZ-GTE not boosting?	SkiDMaN	Wed, 11 June 2003 08:28
	Re: 1JZ-GTE not boosting?	jbrough	Wed, 11 June 2003 12:40
	Re: 1JZ-GTE not boosting?	Norbie	Wed, 11 June 2003 12:52
	Re: 1JZ-GTE not boosting?	jbrough	Thu, 12 June 2003 09:36
	Re: 1JZ-GTE not boosting?	Norbie	Thu, 12 June 2003 10:59
	Re: 1JZ-GTE not boosting?	wilbo666	Thu, 12 June 2003 11:08
	Re: 1JZ-GTE not boosting?	jbrough	Thu, 12 June 2003 11:20
	Re: 1JZ-GTE not boosting?	justcallmefrank	Thu, 12 June 2003 11:36
	Re: 1JZ-GTE not boosting?	wastegate	Fri, 13 June 2003 04:30
	Re: 1JZ-GTE not boosting?	V8_MA61	Sat, 14 June 2003 05:58
	Re: 1JZ-GTE not boosting?	SUPRAGTE	Sun, 15 June 2003 04:33
	Re: 1JZ-GTE not boosting?	jbrough	Sun, 15 June 2003 10:07
	Re: 1JZ-GTE not boosting?	Norbie	Sun, 15 June 2003 13:11
	Re: 1JZ-GTE not boosting?	SkiDMaN	Wed, 18 June 2003 10:48
	Re: 1JZ-GTE not boosting?	MS-75	Wed, 18 June 2003 23:36
	Re: 1JZ-GTE not boosting?	1JZ.747	Thu, 19 June 2003 00:00
	Re: 1JZ-GTE not boosting?	Chris Davey	Thu, 19 June 2003 01:23
	Re: 1JZ-GTE not boosting?	wastegate	Thu, 19 June 2003 02:15
	Re: 1JZ-GTE not boosting?	SkiDMaN	Thu, 19 June 2003 10:25

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