Got Over 400kw Atw?

[r33_racer]

For the tracks we race on in QLD, anywhere between 500-600hp is ideal. Actually its more like 550hp would be the max you would want. Anything north of that in a gtst is just time robbing.

[The Dan]

I guess its better to have head room HP wise, you could run less boost and more timing and make the same power with less strain?

Not always more timing as it's not really being limited by the boost at the moment. I think we are going to have to really sit down and consider all options. It's fair to say we have found the limit of this turbo. Hopefully knowing a benchmark will be all we need to move forward productively

[Harey]

Why not stay with the GT35 and use a 1.06 housing and then drop the boost down a tad until you have similar power to currently? You could even use one of the new GT35X turbos.

[Bunta]

Not always more timing as it's not really being limited by the boost at the moment. I think we are going to have to really sit down and consider all options. It's fair to say we have found the limit of this turbo. Hopefully knowing a benchmark will be all we need to move forward productively

I actually meant to say less timing, sorry typed this while getting earbashed on the phone at work lol, I guess what i was trying to say was milder tune less boost on a the bigger turbo you were mentioning for about the power the old fella wants!

[GTScotT]

well from what we can gather:

3L bottom end + GT3582R with 0.82A/R rear housing

750deg runner temps but possibly exceeding 950 degrees in the housing due to the size restriction. The bearing cage and everything around it was blue all the way to the comp side apparently.

Considering an offer from Garrett but if he moves to the BW turbos it will be a 0.92A/R but better than that it will be a T4 footprint which means more gas flow and less heat. Unfortunately it means more hp which we don't want

I hope this stays well documented.

My brother is on his 2nd 3076 for the same reason. At 18 psi the .63 rear gets white hot on a 2.6L 4 pot.

Can I suggest if a 35R stays on the motor a re-profiled HKS 1.01 rear housing be considered? It is a 3037 housing yet as we all know all 35R housings are simply reprofiled 30R housings to begin with. The HKS housing should open it up as much as necessary without much loss in response, it will also be a bolt on affair as far as the manifold goes (save some $$).

[Marko R1]

For the tracks we race on in QLD, anywhere between 500-600hp is ideal. Actually its more like 550hp would be the max you would want. Anything north of that in a gtst is just time robbing.

anything over 400hp in rwd is a handful

[The Dan]

I actually meant to say less timing, sorry typed this while getting earbashed on the phone at work lol, I guess what i was trying to say was milder tune less boost on a the bigger turbo you were mentioning for about the power the old fella wants!

Yeah I thought that's what you may have meant. That's pretty much the idea he had also

I hope this stays well documented.

My brother is on his 2nd 3076 for the same reason. At 18 psi the .63 rear gets white hot on a 2.6L 4 pot.

Can I suggest if a 35R stays on the motor a re-profiled HKS 1.01 rear housing be considered? It is a 3037 housing yet as we all know all 35R housings are simply reprofiled 30R housings to begin with. The HKS housing should open it up as much as necessary without much loss in response, it will also be a bolt on affair as far as the manifold goes (save some $$).

You can suggest it but I can tell you what Noel will tell me if I forward that suggestion:

gof**kyaself - followed by a beating with a barbed wire stick

We don't want to take any chances, the 1.06 rear MAY.....and I mean MAY be ok but Noel has made it quite clear that he does not want to do this next one on a maybe. He's been through too much already for me to make anything but absolute decisions.

If we go back to a Garrett turbo it will be the GT3788R. This turbo made more hp than the T04Z and came on sooner by about 3-400rpm which is only a tiny bit laggier than the 35R but with the 4088 comp wheel it flows way more air. The housing is a T4 so gas restriction is at a minimum.

It's either that or the Borg Warner turbo of equivalent size which has a tougher bearing assembly, billet comp wheel, turbine capable of higher temps and comes with provision for wheel speed sensor, had a built in recirc valve and is internally gated (yes it's a large gate and has been proven to work at high volume)

I am personally worried about swapping to an unknown device (as in unknown to myself) but we still aren't ruling out Garretts option

[Harey]

I dont understand this the 0.82 housing on the GT35 cannot survive the amount of power and therefore overheats. Your initial comment of not wanting any more hp but then saying that if you stayed with Garrett you would choose a larger turbo. Why would you not choose the 1.06 housing on the GT35 for a slight increase in lag but very similar hp and hopefully some reuse of turbo parts with your current blown turbo??

It would have to be THE most common aftermarket turbo used on an RB30 block.

[The Dan]

I dont understand this the 0.82 housing on the GT35 cannot survive the amount of power and therefore overheats. Your initial comment of not wanting any more hp but then saying that if you stayed with Garrett you would choose a larger turbo. Why would you not choose the 1.06 housing on the GT35 for a slight increase in lag but very similar hp and hopefully some reuse of turbo parts with your current blown turbo??

It would have to be THE most common aftermarket turbo used on an RB30 block.

It's not the power that creates the overheat, it's the restriction. And can you 100% guarantee that the 1.06 rear housing will be enough for him? Give him a guarantee and I'm sure he'll hold you to it.

The fact is that we THINK the 1.06 will be enough but it's not good enough to think it will. We have to know it will.

So if there are ppl who are making 550hp at the wheels on a 1.06 rear running 24psi and can give us turbine housing temps and comp wheel speeds, then I would love to hear from them

[Nee-san]

It's not the power that creates the overheat, it's the restriction. And can you 100% guarantee that the 1.06 rear housing will be enough for him? Give him a guarantee and I'm sure he'll hold you to it.

The fact is that we THINK the 1.06 will be enough but it's not good enough to think it will. We have to know it will.

So if there are ppl who are making 550hp at the wheels on a 1.06 rear running 24psi and can give us turbine housing temps and comp wheel speeds, then I would love to hear from them

Unfortunately the kind of people who would have data for you are the ones least likely to share it.

[Rolls]

Unfortunately the kind of people who would have data for you are the ones least likely to share it.

Why is that?

[Harey]

It's not the power that creates the overheat, it's the restriction. And can you 100% guarantee that the 1.06 rear housing will be enough for him?

Well power=flow and it is the flow thats causing the overheat. A particular size housing will only be able to flow X amount of air at a reasonable temp.

What do you mean will the rear housing be enough for him?? I thought you didnt want anymore power?

So if there are ppl who are making 550hp at the wheels on a 1.06 rear running 24psi and can give us turbine housing temps and comp wheel speeds, then I would love to hear from them

Surely Garrett can supply this information to you? I have attached a plot from the Garrett site comparing the different exhaust housings. Seems to be a significant difference in flow capability between the 0.82 and 1.06.

I would be also reading through the thread below and pm'ing all the guys with the 1.06 rear housing:

http://www.skylinesaustralia.com/forums/Gt...l=T04Z+database

If not enough info here the vl boys on calaisturbo would most likely be able to help.

[The Dan]

What do you mean will the rear housing be enough for him?? I thought you didnt want anymore power?

Surely Garrett can supply this information to you? I have attached a plot from the Garrett site comparing the different exhaust housings. Seems to be a significant difference in flow capability between the 0.82 and 1.06.

What I mean is will the 1.06 housing be enough to drop the temps. Consider this. What if the EGT's exceeded 1000degrees momentarily? Will the 1.06 rear be enough to drop that momentary heat rise to below 850?

We spoke to Garrett in length and their answer was basically this:

We give this charts based on standard vehicles. Noel's engine would be exceeding 100% efficiency. We cannot give accurate guidlines on turbine housing selection or turbo selection on heavily modified engines.

......Yes I did think wtf.

If we swap to a 1.06, what if the housing temps get to 900? They are only rated to 900. It is too close for us to play around with it. I think also that the E85 MAY have something to do with the heat rise also. We are in fairly unchartered waters here with this new fuel and even though logically it shouldn't, I think it is having that added effect.

The V8 supercar guys are having more trouble with engines blowing since the change to E85 than ever before. This is straight from their own mouths. And they believe it is due to the extra heat it is inducing.

I don't know the technical details behind it but I am going to do more research and find out

[Harey]

Very interesting, thanks for the detailed response.

[Harey]

Quick browse through calaisturbo and number 7 and 8 on the 1/4 mile list in QLD run GT35s:

#7 OVL087 - 9.95 @ 137mph ............. 27psi gt35 , glide , roo16

#8 Exchaser - 10.09 @133mph ............. RB30, GT35, mt et streets ,31psi E85, keas 3 speed

From the look of that 31psi and e85 seems to me that the 1.06 will drop temps that much.

[zebra]

But they only run for 10secs at a time, not lap after lap at QR in Summer

[Harey]

Yeah point taken its not a direct comparison but I understand the car we are talking about hasnt been doing laps and laps to bust the turbo either? Did it make it off the dyno?

Personally I think 20-22psi through a 1.06 housing will bring the temps down enough but I am not going to pay if it doesnt so I will be quiet.

[Rolls]

Don't falcons use the same gt35 with a 1.06 rear and make 400rwkw all day with a 4L motor without cooking them?

[zebra]

On pump gas yes, E85 or any alcohol based fuels have WAY higher EGT's which I think is causing the Issues.

Edit, I should say unleaded gasoline being that E85 is at quite a few pumps now

[Rolls]

Interesting to know that E85 has higher EGTs, the fact that it can resist knock a lot more made me think it was the same or lower, is the extra ignition due to its equivalent octane rating instead?