Dump Valves

Discussion and technical advice the SW20 MR2. 3S-GTE, 3S-GE, 3S-FE etc
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Raf
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Dump Valves

Post by Raf »

Hi All,

i was going to ask which is the best dump valve for the tubby but i have heard about AFm probs. Can someone enlighten me please.

is there a way to get around this prob?

Cheers All

Raf
briforbes

Re: Dump Valves

Post by briforbes »

they cause the car to run a little rich between gear changes, as you are in effect letting out air that the afm has metered. I had an HKS valve on my rev1 turbo and to be honest, it's barely noticeable.
Raf
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Re: Dump Valves

Post by Raf »

i was a bit worried because a friend had a K&N air filter fitted to his Impreza and his MAF (AFM) went- cost him £70 to replace with a second hand unit! but worst of all we had to get recovered on a cold winter night!!!

i was just a little concearned that the car wouldnt just give up like his!


thanks for that bud.
Kieron
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Re: Dump Valves

Post by Kieron »

....and it makes you sound like the 11A bus....
shafster

Re: Dump Valves

Post by shafster »

go for a decent dump valve and you should be fine, i haev heard about the blitz one being a nightmare on earlier revision mr2's
Raf
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Re: Dump Valves

Post by Raf »

Kieron wrote:....and it makes you sound like the 11A bus....



thats the aim! :lol:

actually i took the tubby for a quick spin last night (first time) and it sounds like the 11A bus but its a standard BOV????

i have been reading up on them since and i have read that the OEM one is very comlicated (by pass system) which you couldnt get on a after market BOV. then there was another thread about some dudes in the States who did tests and reckon that it doesnt have the by-pass system- its a bit confusing at the moment!

Am i right in assuming that i should have no probs with a Rev3 due to location of the AFM?

[/img]
Kieron
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Re: Dump Valves

Post by Kieron »

To be honest, the general concensus was that a bov was fine on the Rev3+ but not a good idea on Rev's 1 & 2.

We had a bov discussion on the old site, and no doubt some of the more experienced "bovvers" out there will be along shortly to tell you exactly which is the best and the best way to fit.

Sit tight....!
eddy simpson

dump valve

Post by eddy simpson »

i had a blitz blow off valve on my rev2, ok it sounded great but idle was a bit too lumpy. i then changed back to my standard recirculating bov and the car ran great again. so in my opinion it was wasted money. the only good thing was the flames from the rear end due to it running a bit rich!!! :lol:
Cliff
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Joined: Sun Dec 19, 2004 10:57 pm

Re: dump valve

Post by Cliff »

eddy simpson wrote:i had a blitz blow off valve on my rev2, ok it sounded great but idle was a bit too lumpy. i then changed back to my standard recirculating bov and the car ran great again. so in my opinion it was wasted money. the only good thing was the flames from the rear end due to it running a bit rich!!! :lol:


Flames? :shock:. Where can I place my order!?!? :wink:
craig
Posts: 43936
Joined: Sat Dec 18, 2004 3:44 am

Re: Dump Valves

Post by craig »

shafster wrote:go for a decent dump valve and you should be fine, i haev heard about the blitz one being a nightmare on earlier revision mr2's


Only if you use the Blitz MK1 BOV, The MK2 blitz BOV is design with AFM's in mind i.e closed on idle.

I have an air/fuel ratio gauge in my car and I cannot tell the diff to the display between the recirc and atmos!

Put ya foot down, car runs pig rich, like before with the recirc on and runs lean when off the pedal.

This topic has been done to death and at the end of the day, there have been no recorded damages to the engine by using an atmos bov on a pre rev 3.

I love mine. I will not remove it. I had to make my own mind up about it because the opinions were 50/50. I went with JJ's opinion and the girlfriends dad who is a mechanic and a bloody good one at that.

On this topic, I am afraid it comes down to this:

YOUR money, YOUR car, YOUR decision.

That is my opinion anyway.

HTH

Craig 8)
KiwiMR2

Re: Dump Valves

Post by KiwiMR2 »

Raf wrote:

Am i right in assuming that i should have no probs with a Rev3 due to location of the AFM?



Ya getting a bit mixed up there....the Type I & II's have AFM's....the Type III upwards have a MAP system :)

IMO I have read many posts that idle can be effected when the BOV has been replaced with a after market unit and vents to atmosphere, personally i have never experienced this problem..... so I am doughtful, I reakon it's just one more of those myths. idle is not effected, the only effects on idle are for a short period after the bov has done its job, this theory has some merit, (the car had accounted for the air that had just been released), personally i have never seen this, i have owned 2 turbo mr2's all have run amto bov from time to time with NO effect what so ever.....obviously my Type 3 is sweet with the MAP system but many others I meet up with that have turbo mr2's have no probs either.

I have however seen the car idle issues with the OEM unit venting to the atmo....would dip down and stall after venting or coming to a stop.

I believe most of the time anyone having a problem with an aftermarket unit is more likely to have a poorly sealing bov, or just plain cheap and nasty BOV/Install.

If your car has a rough idle a simple test would be to cover/seal the bov to see if the idle issues is solved, if it is then the problem is your BOV is not sealing proper...

It is correct that the stock unit is a goodie and does not need replacement, but what fun would that be 8)

At the end of the day Im with RedMR² though....up to you, at the end it's your choice :)

Cheers
KiwiMR2
pecky

Re: Dump Valves

Post by pecky »

my rev 2 runs fine with my trd bov, had no problems wiv idle or over fueling since i fitted it.

but as every1 says its your choice at the end of the day
Raf
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Re: Dump Valves

Post by Raf »

Thanks guys for the input. Did some more reading yesterday and its definatley a debatable topic. So as to not carry this debate on any longer im just gona stick a loud BOV in it :twisted: . Thanks for all the help!!!
Wayne
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Joined: Tue Jan 18, 2005 4:54 pm
Location: Sunderland

Re: Dump Valves

Post by Wayne »

You'd be best off going for an HKS SSQ BOV.
Raf
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Re: Dump Valves

Post by Raf »

Wayne wrote:You'd be best off going for an HKS SSQ BOV.


hey- nice one, i was thinking about a HKS one (only cos its got the HKS filter)- im not too clued up on all this engine bay teccy stuff. Cheers for that!!! :)
Wayne
Posts: 35
Joined: Tue Jan 18, 2005 4:54 pm
Location: Sunderland

Re: Dump Valves

Post by Wayne »

In my opinion, I recon its the safest, I had a Blitz super sound on my Skyline but had to run it WITH the standard recirc or it would run like a bag of hammers, then I got the HKS Supersiquential fitted which was a direct fitment for the recirc, removed the shitty Blitz one and it runs sweet as ever, so you see where I get my faith from for the HKS SSQ.
craig
Posts: 43936
Joined: Sat Dec 18, 2004 3:44 am

Re: Dump Valves

Post by craig »

Wayne wrote:In my opinion, I recon its the safest, I had a Blitz super sound on my Skyline but had to run it WITH the standard recirc or it would run like a bag of hammers, then I got the HKS Supersiquential fitted which was a direct fitment for the recirc, removed the shitty Blitz one and it runs sweet as ever, so you see where I get my faith from for the HKS SSQ.


I have a Blitz SS Bov on my rev 1........sweet as a nut 8)
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