500HP target turbo - GTX30 vs ?

[mastermind]

Thnx URQ, I knnow of an S2 using a GT30R doing much higher HP on race fuel, so I understood the comparison is about spool, which is exactly the comparison I was looking for.

In your opinion, will the GTX3076 range spool better that the HTA? Or should I just wait awhile for the EFR turbos?

Are these HTA turbo's Hybrid, i.e. do they have KKK hot side to bolt onto my RS2 EM or should I change manifolds?

Also looks like the EFR 7064 would be the one to look at in place of the 3076. The EFR 6758 may just be to little a jump for me from the 3071, but promises to be a good allrounder

[URQguy]

Thnx URQ, I knnow of an S2 using a GT30R doing much higher HP on race fuel, so I understood the comparison is about spool, which is exactly the comparison I was looking for.

In your opinion, will the GTX3076 range spool better that the HTA? Or should I just wait awhile for the EFR turbos?

Are these HTA turbo's Hybrid, i.e. do they have KKK hot side to bolt onto my RS2 EM or should I change manifolds?

Also looks like the EFR 7064 would be the one to look at in place of the 3076. The EFR 6758 may just be to little a jump for me from the 3071, but promises to be a good allrounder

I have not run the gtx Series turbos yet, as they were just released. I intend to do extensive testing once I get my hands on them. I can give you my initial thoughts from talking to the engineers at SEMA in Las Vegas this last month. I am going to say that the gtx is more of a turbo then the HTA. It is a forged billet compressor vs a strait billet compressor which just means that it will withstand higher pressure ratios more easily, and can be thinner blades when compared to the hta counterpart. Also, Forced Performance modifies the GT turbos to make the HTA turbo. They are a fairly small outfit with not a lot of tools at their disposal. Honeywell on the otherhand is huge, and well funded. They have been watching Forced Performance take a market share for the last 2 years. My bet is that they made sure it performs at least as well.

From a price point, it is hard to beat the gtx turbos. It is 1400$ compared to almost 1700 from Forced performance for the HTA.

Now the 35r series turbo is a toss up for price. Its a hard call there.

Now the EFR turbos by Borg Warner will change the turbo world IMO. My bet is that the turbos will spool an additional 400rpm sooner to comparable HTA or GTX turbos and flow just as much, if not more. That is just my humble opinion though. AT Sema they had their new Titanium Oxide exhaust wheels next to Inconnel wheels for comparison. They were half the weight. It would be like wondering if an s2 will rev faster with a stock flywheel or an aluminum one.

Full-race is offering the BW new EFR turbos at killer introduction prices. I am a bit of a turbo nerd, and this will probably be my next turbo. I bet the 8374 will become the new 3076r as the turbo of choice for 2.2 20vt motors. I think it will spool faster then the 30r and have more power than the 3582r turbos. It it is demensionally larger than a 35r on both the turbine and compressor, but with probably half the rotating mass. It should be a wicked 700whp turbo with 30r like spool.

http://www.full-race.com/store/turbos/borgwarner-efr/borgwarner-efr-8374-turbo.html

[Billman]

I see that BW now is trying to take a big share in gasoline turbos with some serious features BUT I have some concerns. It will spool faster because of the lighter rotating assembly + ball bearing but I see 2 marketing points where I would be careful with:

1. Ti Turbine Wheel

Mitsubishi tried it in production cars (i think toyota also) but they proved to be not as good in reliability as the Inconel ones.

2. This trick with the map
they extending the efficiency lines to show bigger flow numbers but at what efficiency % ??

Here you can 2 different in wheel design but close to each other turbos:

BW EFR 7670
Compressor impeller 57.2/76.2mm

Garrett GT3076
Compressor impeller 57/76mm

P.S.: All the BW S300 ect. turbos have similar Compressor maps as the EFR line because of the same impeller design (difference is the Billet).

@URQGuy
Is it possible next time you do a comparison to try any Holset HX40 (Billet or not) turbo with a Bullseye turbine housing?

[repo]

The issue with too lightweight shafts is the lack of inertia. Therefore, an evo titanium shaft turbo drops off from revs easy.

The turbo that'll change the world is a 60lb flowing compressor combined to 4:1 pressure ratio at surge line with 20lb flow. At the moment we have many turbos capable of flowing 600hp, and spooling up wwaayy too early.

Also, CT makes center sections out of aluminum, making a 900hp turbo weighing 9 kilos. Compare to similar capacity B&W, and wonder why I decided not to buy one. So a lightweight and compact design needs to be combined to the high pressure ratio at 20lb flow.

edit: I took a closer look at the surge lines at 200hp range, and looks like the old garrett 4094 and this all new B&W have pretty much identical surge pressure ratio at said power.

And as we can make the 4094 to spool up so early, it surges itself to death, this 83mm B&W will make no difference there. Sorry.

[URQguy]

<grabs popcorn and waits for somebody to pony up and buy one>

Are you trying to talk me into thinking that more weight on a rotating assembly is good? I disagree I am afraid.

I do not see how you are getting away with comparing the 4094r with the BW 8374. The 4094 surges off the charts at ~250hp because it has a HUGE 94mm wheel on a 77mm turbine. This is a mismatched turbo. The better match is the 88mm 4088r that did not surge, but drag racers wanted the bigger wheel. The BW has a much better surge line, and I do not think it will surge on our motors. If it is any indication, the test mule 2L AND 2.2l evo's are not getting any surge at all with this turbo on t3 .83 housings. The 4094 did surge on the same type of evo builds.

My 82.5mm exducer hta 3582r does not surge ANYWHERE on a true 2.2L and 7a cams. I can roll on from 2000rpm in 5th all the way up to 5000rpm and have 14psi by 3800rpm, 25 by 3950 and 35 by 4150. This is all on a .82 Tial housing.

[QuattroFever]

<grabs popcorn and waits for somebody to pony up and buy one>

Are you trying to talk me into thinking that more weight on a rotating assembly is good? I disagree I am afraid.

I do not see how you are getting away with comparing the 4094r with the BW 8374. The 4094 surges off the charts at ~250hp because it has a HUGE 94mm wheel on a 77mm turbine. This is a mismatched turbo. The better match is the 88mm 4088r that did not surge, but drag racers wanted the bigger wheel. The BW has a much better surge line, and I do not think it will surge on our motors. If it is any indication, the test mule 2L AND 2.2l evo's are not getting any surge at all with this turbo on t3 .83 housings. The 4094 did surge on the same type of evo builds.

My 82.5mm exducer hta 3582r does not surge ANYWHERE on a true 2.2L and 7a cams. I can roll on from 2000rpm in 5th all the way up to 5000rpm and have 14psi by 3800rpm, 25 by 3950 and 35 by 4150. This is all on a .82 Tial housing.

i think whats being suggested is that when you lift off the throttle and pressure is released it will lose rpms quicker than a heavier shaft. However, I have no idea if a lighter shaft will spool quick enough to compensate for that loss in rpm between shifts.

[repo]

I was comparing the 4094 to the 8376. Sorry. They perform pretty close to each other.

The smaller B&W looks a lot better, indeed. Especially at the 20lb flow region.

You spool up pretty late, though, and that is why You don't surge. I typically get 2 bar by 3300rpm with 57mm 55trim wheels and 3600 at the latest with 67/84mm on higher gears.

And yes, Ant said it. Certain amount of weight loss is good, but up to a point. That is why most racers dislike the titanium wheel mitsus in rally racing.

[A80Avant]

@URQguy

from the motorgeek plots i cannot see a direct comparison between the 3076R and the HTA3076, so i can see the difference in spool. There is the one that compares it to the 5857 but not the HTA.

[URQguy]

Again, I humblely disagree. How can you look at those two maps and tell me that they are going to perform simularly? The 4094r has a dip to the right on the surge line after 2 bar at 30lb/min flow rates. This happens as the huge compressor is unable to shove all the available air into the motor. If one increases preasure ratios at that level, the motor WILL surge. This is why this turbo is a surge master on street and road race cars.

The BW has a somewhat Linear SL due to a better matched wheels. The exhaust wheels is not outrunning the turbine anywhere, and therefor surge will not be present.

Do you get surge on your turbo? You are running a 57mm inducer on the turbine wheel with a 55 trim? IF I understand your turbine, the exducer is around 76.8mm? What AR ratio on the hotside and coldside.

What kind of pressures do you see in your exhaust manifold in relationship to boost? ie boost/manifold ratio.

[URQguy]

I was comparing the 4094 to the 8376. Sorry. They perform pretty close to each other.

The smaller B&W looks a lot better, indeed. Especially at the 20lb flow region.

You spool up pretty late, though, and that is why You don't surge. I typically get 2 bar by 3300rpm with 57mm 55trim wheels and 3600 at the latest with 67/84mm on higher gears.

And yes, Ant said it. Certain amount of weight loss is good, but up to a point. That is why most racers dislike the titanium wheel mitsus in rally racing.

Yeah, like sequential 6 speeds in shifting at .019 second or faster lapse speeds are going to result in a lot of spin down.

This is a good discussion and I love to learn. Keep the good info coming whether they are opinions or not.

Billman, These dyno's have all been done using my v-band headers. Currently Holset hotside offereings do not lend themselves to the v-band option, unless I welded up a hotside to my likes.

I am building up an urs6 at the moment that will be sporting a holset though. Perhaps we can bring him along next time at the dyno.

[repo]

Well, yes, new BW can withstand a little higher boost at 400hp region, true.

I don't think I have experienced surge issues at 4500-5000rpm/400hp level. Usually on lower, around 200hp region. Once the compressor hits the surge, the whole thing gets unsteady, and it may take ages for the compressor to get back to the map, although it should be well on range. The whole system just gets upset.

Maybe there has been surge at 400hp level, but usually the engine goes up pretty quick, it escapes the surge, as the car accelerates, and typically every 100rpm on that region makes like 30hp more -> more flow/higher surgeline.

And yes, I do experience surge with the +600hp setups I work with, so I need to limit the boost at the midrange. Like said, we need +600hp wheel that would not be as tendent to surge at 3000-3500rpm/200hp level.

I would be more than happy to see this smaller B&W in action, maybe could finally see +800Nm torques from 2.2l setups. The larger one doesn't look too marvellous.

You are now mixing up either compressor or the turbine, or inducer and the exducer. I was talking about oldskool 55 trim comp wheel with 76mm exducer. On turbine side the exducer and inducer are opposite.

Yeah, like sequential 6 speeds in shifting at .019 second or faster lapse speeds are going to result in a lot of spin down.

No matter how hard I try, I do not understand what this means.

edit: I don't measure backpressure, as I know no one on this forum actually knows how to measure it correctly, not to mention what it means. I stopped measuring it, when I realised, moving the measuring point by two inches I managed to lower the backpressure by 7 psi.

[URQguy]

Well, yes, new BW can withstand a little higher boost at 400hp region, true.

I don't think I have experienced surge issues at 4500-5000rpm/400hp level. Usually on lower, around 200hp region. Once the compressor hits the surge, the whole thing gets unsteady, and it may take ages for the compressor to get back to the map, although it should be well on range. The whole system just gets upset.

Maybe there has been surge at 400hp level, but usually the engine goes up pretty quick, it escapes the surge, as the car accelerates, and typically every 100rpm on that region makes like 30hp more -> more flow/higher surgeline.

And yes, I do experience surge with the +600hp setups I work with, so I need to limit the boost at the midrange. Like said, we need +600hp wheel that would not be as tendent to surge at 3000-3500rpm/200hp level.

I would be more than happy to see this smaller B&W in action, maybe could finally see +800Nm torques from 2.2l setups. The larger one doesn't look too marvellous.

You are now mixing up either compressor or the turbine, or inducer and the exducer. I was talking about oldskool 55 trim comp wheel with 76mm exducer. On turbine side the exducer and inducer are opposite.



No matter how hard I try, I do not understand what this means.

edit: I don't measure backpressure, as I know no one on this forum actually knows how to measure it correctly, not to mention what it means. I stopped measuring it, when I realised, moving the measuring point by two inches I managed to lower the backpressure by 7 psi.

Hehe.. Poor american wording on my part. I meant that WRC and even most amature forms of racing use Sequential gear boxes that have shift times of under .02 seconds, in the addition to electronic antilag. The turbine could made of unobtanium and weigh a tenth of the weight of a standard inconnel setup and not experience respool lag between shifts. Porsche is proving this readily on their PDK 997 turbos. They may or may not be using Borg Warner technology.

I am not talking about back pressure in the exhaust, I am talking about pressure in the exhaust manifold, pre turbo. This is a basic pressure reading, and it does not care about location although garrett recommends it at the collector or inlet of the turbo. If you look at the turbine efficiency plots for the hotside, they are not supppose to be under 1:1 or over 1.5:1 and still be efficient. If they are more, usually that points to undersized wheels, too small of hotsides, perhaps both, or oversized compressors. This means that 20psi in the intake manifold should be at a maximum of 30psi in the exhaust manifold. Over 1.5, the compressor will most likely surge.

Lastly, Trim is just a way of quickly saying what the inducer and exducers are. This is a garrett thing btw. a 57mm inducer with a 55 trim calculates out to be a 76.8mm exducer. The simple calculation is (inducer x inducer)/(exducer x exducer) x 100 = trim

So my question is if your inducer is 57mm indeed. If it is, and you are running 67/84mm compressor, I am not surprised at all that you have surge happening on ramp up. I am sure loading it uphill in tall gears results in quite the buck! Tuning it out is a bandaid IMO. Turbo companies build hybrids like these for Drag racing where 2 stage antilag can be used and guarantee that a turbo is never close to the surge line. The 4094r was never intended to be a street or road course turbo. It was built for the drag racer in mind that needed the packaging of the 40r instead of the 42r. They slap big hotsides on them to cheat the wheel sizes, and end up with an unuseable bottom end and a monster top end. This is also why most folks do not put tons of money into bearing center sections on drag cars.

Edit: another thing, cams have a whole lot to do with surge and output of turbos too. You can hold 35psi to redline with a 30r on stock 3b/aan cams, but throwing 7a cams on a 20vt with tube headers and an intake manifold will result in a taper to ~ 28psi by 8500, regardless of wastegate settings.

[diesel des]

That efr map looks great in comparison to the 3076r. Really wide and progressive.

[Billman]

Yep....thats why we are saying all the time that most Garrett turbos have aged designs.

[repo]

Hmm..

I'm sorry if I am putting myself out in a confusing way today, but no, I do not use 55 trim 57mm turbine with 67mm compressor. No. I am using 63 - 70mm wheels, depending on cams with the 67mm compressor.

And the 55trim compressor I refer to, is 57mm impeller, and 76mm and if it has some fractions here or there more or less, I cannot measure with my manual caliper, as every time I put my caliper on, I get one tenth here another tenth there, so I do not know if it is 76,2 or 76,3mm. I usually choose turbines from 57 to 65mm with this compressor, depending on, well, stuff.

Most of us don't have 0,019sec gearboxes. Or PDK transmissions. Most of us have normal hydraulic actuated release bearing and 240mm single plate clutch combined to synchronized H - pattern gearbox. Also the rally drivers I refer to, are the Gr N drivers here in the rally capital of the world, finland, and they need to use H pattern as well, because of the regulations.

Not to mention Ant's example where he spoke of releasing throttle, and reopening it. Which You at some point need to do even if You had 0,017 second gearbox.

I am talking about pressure in the exhaust manifold, pre turbo. This is a basic pressure reading, and it does not care about location

That is so not true. And exactly my point why I don't care to measure it.