Surge Slot Cover

[Beer Baron]

Lastly don't forget that PS housings cost a few points of compressor adiabatic efficiency so they can be a slight step backwards if the thing is not surging , like most solutions they are a compromise with surge being the greater of the two evils .

very important point. no point getting a port shrouded/anti-surge cover just for the sound. they are only necessary on set-ups that suffer from surge. otherwise you are losing efficiency for nothing. well for the sake of a noise. it may sound cool, but not as cool your competitors only get to hear it as their car goes blowing past you...

[DCIEVE]

The GT30R and GT35R use the same exhaust housing castings but machined to suit each turbine.

As Disco said. Anti surging the GT35R comp cover is probably going to cost you power.

I looked into this a while ago as I was interested to trial a 3076 in place of my 3582 but looking on the garrett site it didnt look possible. Not that the 3076 dwg is particularly clear.

http://www.turbobygarrett.com/turbobygarre...14568_1_2_3.jpg

http://www.turbobygarrett.com/turbobygarre...R_700382_12.jpg

[Billet Ricky]

I looked into this a while ago as I was interested to trial a 3076 in place of my 3582 but looking on the garrett site it didnt look possible. Not that the 3076 dwg is particularly clear.

http://www.turbobygarrett.com/turbobygarre...14568_1_2_3.jpg

http://www.turbobygarrett.com/turbobygarre...R_700382_12.jpg

Would of swapped right over but the comp covers are different.

Exhaust housings are same, same but machined to suit their different turbines.

We will often use a GT30R exhaust housing and machine it to suit a GT35R if there is no GT35R housing available as I’m sure most other turbo shops do as well.

[unique1]

i also have the 3076r and the sound is awesome, sounds wayyyy better than my hks t04z on my other engine, not sure why but it does, sounds very jet like on spool up.

[discopotato03]

Your calls I guess but I'm more interested in function and cost than advertising .

Really IMO PS housings turned up on HKS spec Garrett turbos because they knew people would run them with smallish A/R turbine housings and that they would surge with bigish trim compressor wheels .

If you go right through their range of petrol engine turbos you'll see that they also usually had a few optional compressor trims and that makes a difference too . Smaller (than the largest) wheel trim options is not such a bad thing response and thermal efficiency wise , with many wheel designs its often the middle trim size that the sweet spot and larger or smaller trims intended to bridge the gap with the existing and next larger or smaller diametre wheel families .

This is getting a bit off the track but I'd say the origins of these petrol BB GT (30/35 series) turbos came from HKS wanting Garrett to use their most modern wheels and putting them on a shorter smaller sized cartridge than they were designed for .

To make them "spool" early the housings also need to be small compared to diesel engine housings and this is why I reckon people have surge or creep problems .

If you use or recreate exactly a HKS model specific turbo you shouldn't get the problems because someones already sorted them out .

It's not the same deal with a Garrett generic turbo because they don't have the fixes in place , that's left to the user to sort .

Outa time , cheers A .

[Beer Baron]

you know more about turbos than is healthy.... but I love you anyway discopotato.

[tridentt150v]

I opted for the PS because with it you eliminate the effects of surge.........I don't know if I had surge, but didn't really want the issue to start with. OK I may have sacrificed some power, but I could have also saved some grey hairs and $$$$ deducing that my problem was surge and then having to buy a PS comp cover as an extra. The downside, I could be loosing a bit of power for no good reason because I took the safe bet.

The PS comp cover also fits in with my future mod plans where I believe the chances of having surge will be greater.

PS Couldn't give a rats about the noise, not my thing really.

[NYTSKY]

I dont think i sacrificed much power with the surge slots on my GT3076 .82

It made 293rwkw very easily on only 17psi (RB25DET) with a very basic tune.

Would have cracked 300rwkw with more tuning.

[PM-R33]

Sacrificing a couple of hp you won't even notice to have a turbo that sounds like a jet engine turbine under spool, i think i can live with that

[T04GTR]

if you want the noise try a borg warner... they sound insane and seem to shit all over the garrets in power and responce despite being bush bearing

[NYTSKY]

Dave,

Found this vid on youtube of an RB26 powered 300zx.

http://au.youtube.com/watch?v=gHToCueBeyo

It uses the BW S360, it sounds like it comes onto boost quicker than my GT3076 and makes 530rwhp!!!! Insane response and power!!!!

And the power band is huge!!!

[discopotato03]

A bit of a grey area but I think S200SX's and S300SX's are original BW turbos , mobs in the US alter them and hang slightly different names on them . Geoff Raicer (fullRace Geoff) is the one to ask about them .

A real GT3076R with a big A/R twin scroll turbine housing is supposed to top out at 570 Hp .

A .

[Cjmartz2k]

570 at the motor, right?

The B-W's, from what I understand, run in generations kinda like the holsets (and Schweitzer for that matter). The non-extended tip ones are pretty much spot on with the holset HX series. The ones you are talking about being altered are still factory BW pieces, just the newer generation. BW and holset used to be real buddy buddy, but they split somewhat on the last generation of turbo's each produced. BW went in the direction of "extended tip technology" and holset went on to variably geometry exhaust housings in their HE series.

*Edit-BTW, that RB26'd 300zx is on NICO and I talk with him frequently on there. I think he went from a GT series to a BW looking for better response and found it IIRC.

Edited December 25, 2008 by Cjmartz2k

[KiwiRS4T]

Hi all,

Im thinking of changing the front and cartridge of my turbo to a GT35R as the rear housing that i have is the same on both the GT3076 and GT35R? Correct?

Ive been looking for a Anti surge cover for it and the only ones i can find are the hole type like the T04Z and Turbonetics GTK turbos.

Is there a surge slot cover in .70 similar to the .60 on the GT3076?

Do they make this style of surge slot cover for the GT35R

Contrary to suggestions that my new GCG highflow would be laggy on my RB25DET Stagea it actually boosted up really quickly low down producing surge. I have overcome it with my Jaycar IEBC which means that I can reduce boost at low injector cycles (engine load) to about 12psi and push it up again at high speeds (from about 3500 on) to 16psi. I am going to get an adjustable exhaust cam gear which should enable me to raise the boost lower down a bit without surging.

I think that the advantage of this over anti-surge slots is that the loss of boost induced by them would be felt further up the rev range (although it would probably be overcome at higher loads).

[Lithium]

It uses the BW S360, it sounds like it comes onto boost quicker than my GT3076 and makes 530rwhp!!!! Insane response and power!!!!

And the power band is huge!!!

It sounds laggier than my GT3076R to me, and a GT3076R will make 530whp if it were tuned on a suitable motor with 85% ethanol blend - as well as spool a bit better.. Be very interesting to see a dyno plot of that car.

[NYTSKY]

It sounds laggier than my GT3076R to me, and a GT3076R will make 530whp if it were tuned on a suitable motor with 85% ethanol blend - as well as spool a bit better.. Be very interesting to see a dyno plot of that car.

GT3076 make 530rwhp??

Thats over 370RWKW.

[jet_r31]

I will go go against the grain and say from what i have read on the internet, the bw

stuff seems to be laggier than the garret stuff, especially in 2J circles

cheers

darren

[Cjmartz2k]

I will go go against the grain and say from what i have read on the internet, the bw

stuff seems to be laggier than the garret stuff, especially in 2J circles

cheers

darren

http://forums.evolutionm.net/service-parts...roll-gt35r.html

Seems not so in this case.

Also, I think the BW S360 is a way bigger turbo than a GT30r series turbo. It's a 69lb/min turbo so it should make close to 700hp at the motor. It's pretty much the same thing as my HX40 holset.

Here is a 300zx/FairladyZ running a BW360 in the states. Full weight (around 3600lb's) running mid 10's.

http://forums.nicoclub.com/zerothread/3814...-damned-time10s

[NYTSKY]

Damn, if only my new manifold was T4 split pulse. I would seriously try one of those BWS360 turbos out.

Maybe next xmas

[Lithium]

GT3076 make 530rwhp??

Thats over 370RWKW.

Correct Honda and EVO guys have been getting >500whp/low 10s out of them for years now.