dumpvalves -which one?

[rob900t16s]

Hi guys,

After modifying my APC I'm now looking for a better dump valve.
Can any of you give advice on the different valves that are on the market?

I am particularly interested in the group 9 performance "Hyperboost turbo bypass valve" for $140
Is it any good and good value for money?
What dump valves do you all have and are you satisfied?

Hope to hear from you all soon so I can make my decision.

Robert
'92 900t16s

[eric900spg]

I am running the BOV from abbott. it is a forge unit. It has none of the problems people seem to complain of (stalling when shifting etc) and makes the turbo get back on boost quicker after a shift. about the same price too. and you dont need their kit to "relocate" it. just trim back the original hose so the valve sits atop the engine and plug the empty hole where the original went with their supplied plug. have pics if you want

[rob900t16s]

I am running the BOV from abbott. it is a forge unit.

I'm sorry if it's an obvious question, but what does BOV mean?
Can you also tell what the number of the forge unit is? I saw them on the site of "parts for SAABs" as well and they seam much cheaper than the one Abbott supplies...

and you dont need their kit to "relocate" it.
Relocate? where does the G9P unit go then?

just trim back the original hose so the valve sits atop the engine and plug the empty hole where the original went with their supplied plug. have pics if you want

I would very much like to see how it looks; is it an easy DIY-job?

Perhaps off topic but I'm sure you can answer that:

Abbott also recommends their 3.3 BAR FPR; is it a Bosch unit (if it is it's perhaps cheaper to obtain elsewhere) and is it the best solution? (since they disapprove of the RRFPR....)

Hope to hear from you soon.

Robert

[eric900spg]

bov means Blow Off Valve. it dumps the air into the engine compartment rather than recirculating it. it is a very easy diy job. not sure the # right now, but I can get it later if you want. might be able to get it off the abbott site as well. I am running a 3bar fpr from a 900s (na) I got from the junkyard for $10. I have a a/f ratio gauge and am running about where I want it to as far as fuel goes. let me know if you need any more info, I check back a few times a day hope this all helps

PS, excuse the dirty engine compartment. it is a pic from when I had it installed on my girlfriends car and it has 365k miles!

[Matthew]

Originally Posted by rob900t16s

they seam much cheaper than the one Abbott supplies...

That seems to be the story of Abbott's entire product range

[rob900t16s]

Hi Eric,

If it's not too much trouble I would appreciate if you'd look up that number for me...

I have a 900t16s? don't I have a 3 bar unit already?

dirty engine compartment? what do you mean? :-?

Maybe you ought to clean the engine compartment for her....

[spence]

ive got the bailey bdv26 i think the forge is the fdv004 we need these because of the amm i think these are twin piston bovs hope this helps :wink:

[Matthew]

Originally Posted by rob900t16s

I have a 900t16s? don't I have a 3 bar unit already?

On a Bosch LH2.2 equipped car, the FPR is 2.8bar unit. LPT (Lucas) and normally aspirated 900s got 3.0bar, and I think some early T16s got 2.5bar regs.

[rob900t16s]

Could I also use the forge FMDVS007P(A) (piston operated) and can this one be placed instead of the stock item or do I then have to make some modifications as well?

Or can I only use an atmo dump valve on my '92 900T16S (with AMM)?

Help me on the theory here... Does the combination of single piston dump valve and AMM give problems at idle? the answers on previous posts is a bit confusing (some poeple say it's not a problem when you have Lucas injection (like I have on my car)

Feed me with info please...

[eric900spg]

http://www.forgemotorsport.com/vehic...roduct=FMDV004

this is the dump valve I have, although shown in a different color. hope it helps. and yes, it is a twin piston design

[Alex]

Originally Posted by Matthew

On a Bosch LH2.2 equipped car, the FPR is 2.8bar unit. LPT (Lucas) and normally aspirated 900s got 3.0bar, and I think some early T16s got 2.5bar regs.

Catalyst equiped Bosch cars also used 2.5bar regs.

[Matthew]

Just out of interest, which regulator was fitted to LH2.4.x cars in the US?

[Alex]

LH2.4 and 2.4.2 were used on catalysed cars so would be 2.5bar for the turbos and 3bar if fitted to an injections.

[uberfast]

Originally Posted by uberfast

I've been using a VTA BOV since september, and let me tell you, ever since then, I've loved every minute of it. If you want some pros and cons about VTA vs recirc this is what i've got.

Cons: As from the posts above, the AMM and dumping air doesn't work out too well. Idling problems (with certain recircs, not all!). Extremely rich mixtures after a ventilation. That can hurt catties and o2 sensors, but that rich mixture only happes for a few moments when the valve goes off.

Pros: Obviously the sound, right? I've been told from a VW buddy of mine that a VTA are much quicker in response than a recirc. And with a recirc when the valve is recirculating the excess boost all the air is hot and running in a circle heating up more before that hot air is used. When a VTA blows that hot air out during a gear change, the air that comes in the engine is fresh cooler air. I suppose that if you have an h2o system then you would have to worry about the hot air issue with a recirc, but it's always nice to have cool air if you don't have h2o injection.

A lot of the VTA's out there are pretty cheap because they will open up on idle and cause you some probs. You can look into an electronic sensor controlled VTA for precise ventilation. I purchased a TCC Work Stage III VTA BOV and it's adjustable which is good so yo can set it according to your boost, and with this valve it doesn't open on idle.

Hope I cleared up a few things.

P.S. VTA = vent to atmosphere

[4saabstoomany]

this posts like tiwce a month. Do a search for "dump valve"
BOV, ATMO. Good god there is more there to read when you search then we could ever type.... (again)

[rob900t16s]

Eric,

Could you send me some more pics? I can't exactly see where your BOV is mounted to
And where is the stock part mounted? Was looking onder the hood a while ago but can't seem to quite locate it....

[CaptRossco]

Hello Rob

I see your new. The BOV or dumpvalve swap/ upgrade is quite simple and something which has been done in some fashion or another by nearly everyone who's upgraded there car or just looked to renew old parts. Theres no official way of doing it, so it doesnt matter if your pipes arent the same etc, dont worry.

The general rule of thumb, is, once you've chosen your dumpvalve (you dont have to have to atmosphere you can renew a recirc system with a piston alloy type!) to have it posistioned as close to the throttle body as possible.

Erics pic shows his atmos valve using the old pipework but switched 180 degs so that the pipework allows for the right apertures etc. As long as you close the system, ie plug the end if your not refitting a recirc theres will be no problem.

Id show you my unit (same as erics just trimmed up closer to the t/b but ive no pics to hand-sorry).

Originally Posted by 4saabstoomany

this posts like tiwce a month. Do a search for "dump valve"
BOV, ATMO. Good god there is more there to read when you search then we could ever type.... (again)

......... :-? This fellow is right, but your not to know about such facilities just yet and these forums are for asking about a finite topic so information by default will be repeated. Rob I soon learned who to listen too and who could be helpful. I also learned to ignore unhelpful rude people, but this is life and unfortunatley you get them everywhere even on here ops:

If you visit widde's site @ www.900AERO.com and go to DIY/ upgrade BOV he shows pics and gives explanations.

Also I know spence has some photo's to hand of his car. In fact I have them on my machine and would forward them to you if spence doesnt mind. They are good shots (he should be a photographer :wink: ) and will help you understand what were talking about.

Best of luck mate

Ross

[Oil_Eater]

Originally Posted by Alex

LH2.4 and 2.4.2 were used on catalysed cars so would be 2.5bar for the turbos and 3bar if fitted to an injections.

Don't forget a 2.8 bar for a factory installed red box equipped car.

Jay

[spence]

thanks ross here is one of mine thats at hand

[rob900t16s]

To all you guys (especially Ross), even the less patient ones :-? , thanks for your good advice.
I made my order at PFS; it will be a forge unit, the FDV004 with plug.
I could send pics after installing if you'd like that...

I'll get back soon!

Robert
'92 900T16s