Replace the G30 770 or upgrade g35 900

[Lithium]

4 minutes ago, Russdmuss said:

Good point lithium, I noticed when using the traction control the boost would spike quickly during Cut events when looking at the data. Might be worth monitoring it against a speed sensor. 

If you're not using throttle control for torque management probably not sooo much of a thing, but ignition cuts are pretty hard on stuff.... not necessarily something I'd totally expect to cause this kind of failure though.

1 minute ago, Komdotkom said:

To the best of my knowledge GPR doesn't do torque management so you don't have to worry about that aspect of it. I haven't tried but you should be able to build a table for turbine speed vs WG position or DC to prevent future explosions.

A mate runs a 40mm DBW TB to atmosphere as a boost bleed pre TB and fresh air anti lag. This results in wild turbine speeds and response. And broken turbos!

Cool yeah not familiar with the GPR so was just saying it in case it might be - and yeah with the GTR package there are ways of adjusting the boost targetting as well to avoid massive silly things from happening.  

[Komdotkom]

The pro package is really more about the contact patch of the tyre and building a model around that as a target. This is largely managed through DBW position but wheel slip and boost are also variables. I've got 12 position switch for target power and another 12 position switch for 'traction', it then dreams up a map in between the two by shaping the boost curve and DBW position to suit.

I'll shoot you a map if you want to have a squizz

[Russdmuss]

Differently genuine garrett this time around and will start looking into what tables I can build to monitor/control turbine speeds. 

The car runs a similar setup to your Komdotkom with two rotary switches one for power and one for traction control at 2% increases. 

6-8% slip seems to be the fast as it just starts to slip but doesn't take too much power to control in the lower gears. 

I'm really impressed with the motec this far, step learning curve for me with ecu's but motec support has been very helpful with any questions or help. 

 

 

 

 

[Komdotkom]

Who's doing the tuning for you?

[infomotive]

On 16/10/2023 at 11:33 PM, Russdmuss said:

Hi Guys, 

Just wanting to replace my current turbo (pulsar g30-770)which has catastrophically failed,  I believe it was from over-speeding but can't confirm that. 

The car 

S13 with rb25 neo with Tomei procams type b, rod bolts, metal headgasket, plasmaman plenum, standard exhuast manifold with external gate welded on and pulsar g30 770 .83 housing. 

Car made 591hp at the hubs on just over 26pd

The purpose of the car is some street driving but does a lot of circuit racing and tarmac events. 

The car is great to drive super responsive on the street and track, as the engine is getting built as we speak and the turbo has failed I want to replace it with a garrett unit and a 6 boost manifold. 

Question is would a twin scroll g35-900 1.06 be as responsive? Or do I stay with a g30-770 and move up to a larger rear housing. 

Yes I know it's been covered in other sections but haven't found and real back to back information. 

Thanks Russell 

Likely over-sped.

I just finished testing on a stock long block neo with bolt-ons.

PSR5855G T4TS 0.85, P98, 25 psi 522 whp chassis dyno. Calculated and actual elevation 300m.

157000 rpm measured shaft speed at 7500rpm.

Did have slight manifold leak when pressure tested.

I would go with the 6255G to give you lee-way.

PSR6258G version on built motor with cams was at around 130000rpm at 25psi 8200rpm and approx

600 whp, struggling with traction. No boost leaks.

Whatever way you go doing a pressurized leak test is a must. Most systems have multiple leak points

people are unaware of until tested.

Hope this helps.

 

 

[infomotive]

Just had a look at the dyno chart and it seems quite laggy indicating potential system leaks, restrictive intercooler etc etc.

[Russdmuss]

10 minutes ago, Komdotkom said:

Who's doing the tuning for you?

Rob Novak from definition motorsport, he been tuning my cars since 2004. 

[Russdmuss]

4 minutes ago, infomotive said:

Just had a look at the dyno chart and it seems quite laggy indicating potential system leaks, restrictive intercooler etc etc.

Thankyou for that data it is all helpful and taken on board.

How did you find the 6258 in drive ability and response aposed to the 5855

I did pressure test it once i fitted the pulsar turbo but it did have chinese cooler and std exhuast manifold with 3in exhuast very primitive low cost setup. On the street it was full boost 26pd at 4440rpm. 

[Lithium]

On 19/10/2023 at 12:50 PM, infomotive said:

Likely over-sped.

SR5855G T4TS 0.85, P98, 25 psi 522 whp chassis dyno. Calculated and actual elevation 300m.

157000 rpm measured shaft speed at 7500rpm.

Did have slight manifold leak when pressure test

Whatever way you go doing a pressurized leak test is a must

Not to question this data at all, obviously very good input and context been given but I thought I'd add stuff from some data I've got for a car run in a hub dyno (these numbers are from a roller dyno that reads more like a Mainline/dyno dynamics roller than a Mainline hub) where we have pretty high confidence of no leaks etc.  It's not for a G30 770 but should add some perspective.

A mate's SR20VE with a Garrett Gen2 GTX3076R made 597hp @ hubs on E85 at 23psi at a bit of altitude, with 131,000rpm turbine speed.  These don't have as efficient a compressor as the G30 770 and have the same max turbine rpm (around 145,000).  Also gives a better lock on conversion of hub HP vs flow on E85 for a rwd on a Mainline prohub. 

If the are no leaks, the Pulsar G30 770 flows about the same as the Garrett version etc it seems like they shouldn't be at a point they are exploding at this power and I might go checking now, but I could swear others have made this power area fine already with them.

 

Edited October 21, 2023 by Lithium

[hypergear]

I found G30 turbine doesn't have enough turbine to run 900 series compressor wheel, you find G35-900 makes alot more top end. Having said that I can rebuild and hybrid your current 770 that makes more power without too much lag and better reliability.

Add:

After reading your dyno print. It should not reach shaft speed limitations at 26psi. This usually happens when compressor is fully maxed. When I was conducting bearing threash hold few years back, 54/55mm chra exploded at 38psi while 58/62mm configuration exploded at 41psi.  Test conducted based on a built EA888 Gen 3 engine. 

 

Edited October 30, 2023 by hypergear

[asvpzane]

Had the exact same thing happen to me last year with my G30 770 .82 making 350kw on 26psi 98 fuel on a built RB25det neo.

What turbo did you end up going with OP? I did consider the G30 900 but genuine this time or a turbosmart 6262 with a smaller rear housing going flex fuel this time around
 

[hypergear]

This might be interesting for some people whom after abit more then a G30-900. This is a comparative graph running an G30-900 copy Vs G30-900 revised (Ss3ProR). Very similar in response to a G30-900 while making 71kws of extra power. Test car is on a Rb2530det run both turbos to a point that no more power could be made. T3 .82 rear housing, E85 fuel, Hub dyno tuned.

 

 

 

[Russdmuss]

@asvpzane I haven't bought another turbo yet as the engine was damaged as well, engine is almost done now.

I'm leaning towards the turbosmart 6262 turbo as it's slightly bigger then g30-770 and hopefully still similar in response. 

I'll fit in a speed sensor as well and update this section once it up and running.