External wastegate function!

[Mr_7]

hey guys,

Going single got most things now and my manifold arrived the other day and is pure art!!! :InLove
Obvioulsy it runs an external wastegate setup which is cool but im not too sure off its function???:2Confused (i believe it regulates boost pressure, but does it  also idle through it and bypass the exhaust on idle?)

Also as i am yet to buy a wastegate so what would be the difference in buying a 40mm and a 50mm, i think i would be able to fit either!


AND if thats not enough questions what sort of spring rating do i go for? i mean are these things adjustable?

thanx in advance:driving

[kev-yorks]

Wastegates only vent excess pressure they do not come into play until you reach full boost. As for size you need something to suit the manifold is it set up for v clamp mounting or bolt on if bolted what hole configuration? 40mm should be more than big enough 50mm flows about a third more. But it all depends on the set up of the manifold. I was running a 38mm wastegate with a gt42 turbo with no issues whatsoever but it was a custom manifold and the natural flow of the gases took them out of the wastegate. Alter the pipe work and flow paths and it wouldn\'t of been anywhere near big enough for that turbo. So its all subjective. As for spring rates if you just want the wastegate to control boost then get a spring at the pressure you want to run. If controlling electronicly like most of us then fit a light spring and let the boost controller do the work then if the electronics fail you\'ve got a failsafe low boost setting. My new wastegate will be running a seven psi spring only then electronicly controlled to 1.2 1.3bar whatever i decide to run. Sorry for the long reply but what works for one might not work with your setup give us as much info as poss and pics and we can help you more. ie is the motor ported or will it be in the near future, stock exhausts/decats etc etc also what boost do you want to run it is easier to control 1.3bar than it is 0.6bar.
  Kevin

[Mr_7]

The manifold is bolt type 4 stud. what do you mean a 50mm runs a thrid more than a 40mm?

My set up is as follows:

GT42R turbo
FMIC
1600cc secondaries (not sure for primaries wether 550 or 850?)
Street porting
Decat
Apexi pfc
044 fuel pump
up rated pressure reg
water injection

im wantinf to run around 450RWHP any help?

[kev-yorks]

Your going into the big boys club then. Without a pic of the manifold to see how the wastegate will flow id say go for a 50mm one or bigger allways edge on the safe side. The reason why a 50mm flows so much more than a 40mm is the size given is the port diameter you times it by pie (3.14 or something like that) to get the cross sectional area of flow. As for the mounting its a case of do some research and see what will fit or get the manifold altered to suit the wastegate you want to use. One word of caution get the wastegate wrong and you can get boost creep which can kill your engine if your unlucky. A good one isn\'t cheap but cheaper than a new engine! To give you an idea on price the turbosmart 50mm wastegate won\'t give you much change from £500.
Kevin

[strange_days_uk]

One word of caution get the wastegate wrong and you can get boost creep which can kill your engine if your unlucky. A good one isn\'t cheap but cheaper than a new engine! To give you an idea on price the turbosmart 50mm wastegate won\'t give you much change from £500.
Kevin

This is something I am currently discovering.

I got mine from this guy

http://cgi.ebay.com/ebaymotors/50mm-hks-style-racing-wastegate-kit-4-bolt-flange-11psi_W0QQcmdZViewItemQQcategoryZ33742QQihZ002QQitemZ120068995126QQrdZ1QQsspagenameZWDVW

It is manufactured very nicely, and you would think it is a fairly simple spring in a tube, but I am getting the odd bit of creep.  Nothing worrying, I never get over 1.04 Bar on the Apexi, and generally holds 0.8 around town, but in the high gears does creep a little and can spike on a short burst in traffic.  I don\'t think this cold weather helps.

[Mr_7]

NIce one kevin thats alot of help thanx,

I am hoping to join the BB\'s club in spring il keep updating in progress thanx again

[kev-yorks]

If your looking on ebay don\'t buy from ss autochrome. There quality control can be indifferent at best though there prices are good. Two makes you can\'t go wrong with are turbosmart and trial, not saying there aren\'t other good ones out there but these two i would vouch for.
Kevin

[rx7veilside]

i have a external wastegate for sale was used with my gt35/40 not sure of make look in for sale section 50.00 plus postage

[Mr_7]

i think tbh i will buy new as everything else is least that way i got something to fall back on (i hope lol?