hi all, just going back to the subject of wastegates if you dont mind, i've seen at least two 1.8 t car's at santa pod this year both running garrett gt28's or similar, both were internal wastegate but on both the actuator had been removed and replaced with a solid rod sealing the internal wastegate, then a external gate had been fitted. anyway what i was woundering is, is there anything to be gained from this or is it a pointless expensive waste of time?
i'm not to sure on the reason behind them doing this, i think one was having trouble with a restrictive downpipe hindering performance of the internal gate, and i guess they wanted the spool of a small ish turbo with the benefits of and external gate, but who know's. i've also seen some of the subaru lads are running a split bellmouth/ downpipe thingy on internal gate turbo's which seperates the flow from the gate then re-enters the flow further down the downpipe, and they all seem to rate it highly! not sure if this would be any good on a 1.8t lump?
Jon@VAGWORX
Guest
Baisically, if you use an exhaust that is too free flowing, the lack of backpressure lets the air pass through the turbo exhaust wheel instead of going through the actuator hole. This renders the actuator useless (in worst case scenario's). So, you either give the exhaust more restriction, or you fix the actuator closed and use an external wastegate.
why would the wastegate be open unless its to reduce boost from n75 control?
are you describing creep?
are you describing creep?
Hi Bill
I presume you used the 8 cm housing on the Green ?
Does the compressor housing clear the head/block or did you have to cut a bit away ?
Bernard
yes 8cm from red lately but previously it was 7cm.. no trimming of head req'd on my manifold. (top mount remember)
8cm was laggier than 7cm on green
8cm was laggier than 7cm on green
Ooops, yeah forgot about your top mount installation. Do you reckon the Green would fit on the Jabba manifod ?
Bernard
Bernard
not a chance. been there. hence went top mount
junk the jabba mani and allow something which fits easier and allows greater choice of turbo.
junk the jabba mani and allow something which fits easier and allows greater choice of turbo.
Bummer ! can't go that route in an Elise without losing a lot of the boot and toasting the back of the engine bay. I reckon a TD05 18G is the best I'm going to get in there.
Bernard
Bernard
does anybody know anything about the ihi vf38 twin scroll, i know the spool is supposed to be very fast, but what garrett turbo's could you compare it to, would it offer gains anything like the vf34 does on a 1.8 20vt lump.
anything bigger than the ihi vf34 turbo on the jabba set up is a pain in the arse imo.Been there ,tried it,didn't work.That's why i went for the jbs set up,My TD05/20G is not as good as i thought it would be tbh
the most bhp it's made is 372@25psi and it makes 1 bar by 3200rpm but doesnt hit full boost till 4800rpm!MRC said that they had to map it like this as it was surging too much
i want a turbo that'll make 450bhp so i can ditch the nitrousSimilar threads
