rev limit for the big singles.

ianong said:

At my current bpu level, it seems pointless to rev beyond the factory redline. What abt you guys with the t78 or to4r. How much have you raised the rev limit to and hows the pulling power beyond factory limits?
Thanks.

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imo... I wouldnt recommend raising the rev limit, seems alot of guys that raise the rev limit w/ big turbo's blow their front main crank case seal very easily.

take care,
nils

On an Automatic Supra with a 4K stall the rev limit will have to be raised... Thats the dilemma I'm dealing with at this time.

Re: Re: rev limit for the big singles.

nils said:

imo... I wouldnt recommend raising the rev limit, seems alot of guys that raise the rev limit w/ big turbo's blow their front main crank case seal very easily.

take care,
nils

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what can be prevented?? Big single turbo does not give you full boost until 5k and if you don't up your rev limiter the you got to shift at 6.5k.

once if your front main crank case seal are blown then what do you need to replace? head?? thanks.

Re: Re: Re: rev limit for the big singles.

supra178 said:

what can be prevented?? Big single turbo does not give you full boost until 5k and if you don't up your rev limiter the you got to shift at 6.5k.

once if your front main crank case seal are blown then what do you need to replace? head?? thanks.

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Well, if you catch it before all oil dumps out you wont have to replace anything but a new seal. Check out the link below:
http://www.to4r.com/tech.html

compliments of Lance W. =)

take care,
nils

Re: Re: Re: Re: rev limit for the big singles.

nils said:

Well, if you catch it before all oil dumps out you wont have to replace anything but a new seal.

compliments of Lance W. =)

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I read the article at http://www.to4r.com/techcrankseal.html Nils, and I was wondering if anyone _has_ enlarged the pressure relief valve return hole and solved the problem...?

I'm curious... TIA.

it didn't provide any solutions??? does anyone have a solution for ths?

No realistic attempts towards fixing this "bug" has been made to my knowledge. Most guys just replace the seal and say "oh-well". I personally have never blown a seal but I have seen lots of Supra's do it. When it happens to me I will definitly explore the problem (knock on wood).

It would definitly be worth it for someone to "fix-it"

take care,
nils

Re: Re: Re: Re: Re: rev limit for the big singles.

quick said:

I read the article at http://www.to4r.com/techcrankseal.html Nils, and I was wondering if anyone _has_ enlarged the pressure relief valve return hole and solved the problem...?

I'm curious... TIA.

Click to expand...

Not to my knowledge =(

take care,
nils

supra178 said:

it didn't provide any solutions??? does anyone have a solution for ths?

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There is a proposed solution at http://www.to4r.com/techcrankseal.html

quick said:

I read the article at http://www.to4r.com/techcrankseal.html Nils, and I was wondering if anyone _has_ enlarged the pressure relief valve return hole and solved the problem...?

I'm curious... TIA.

Click to expand...

I have gone through a couple of crank seals already. I've talked to Jeff Watson from Jay Marks Toyota and he said that when he blew his crank seal, he enlarged the pressure relief valve on the oil pump. He has not blown the seal since. Of course, that does not mean that the mod worked since alot of people just replace the seal and haven't had a problem again. Maybe someone could test this mod out?

Re: Re: rev limit for the big singles.

Weiyan8 said:

I have gone through a couple of crank seals already. I've talked to Jeff Watson from Jay Marks Toyota and he said that when he blew his crank seal, he enlarged the pressure relief valve on the oil pump. He has not blown the seal since. Of course, that does not mean that the mod worked since alot of people just replace the seal and haven't had a problem again. Maybe someone could test this mod out?

Click to expand...

How difficult is it to change replace the crank seal?

I wonder if too much oil and improper crankcase breathing causes some of the seal problems guys are having as well.

just a thought

has anyone considered a combo aproach of enlarging the the pressure relief valve orifice by say 10% and installing an accumulator?
Tony
Also if not 10% then how much should it be inlarged?