riceball777

Setup and dyno results are on my signature

395whp at 11psi on straight 91 octane and 501whp at 17psi on e85. Stock unopen f20c

kbouchard1092

That is really impressive to get 500whp on a 50 trim at only 17psi...I know F series generally make more power. I wouldnt have thought the 50 trim to even hit 500whp let alone at 17psi on a 49/lb min Turbocharger.

MugenSpeclNY

Lets keep this on topic for the most part please. Thread is about the gtx3576r and the rest of the gtx series.

Tried searching around some more, found a thread on the subbie forums about the 3576r but read thru 15 pages to find no real information of value.... Ima keep looking...

TKERacer619

460 @ 14psi on 84.5mm b18c. GTX3071R. E85. MILE HIGH. tuner says it will hit 600 no sweat.

Turbo-LS

iTrader: (4)

Not to keep things off topic but id like to see a dyno of that 50 trim making 500whp. last i knew there a 425hp turbocharger.

SuperChargeEF9

Don't know about the gtx3576 but my boy got gtx3582 and it make way more power then the reg. gt3582. His evo9 make 701awhp on e85. (gtx3582).

riceball777

Dyno is in the like on my signature. Before this billet compressor wheel thing came out 50 trim turbos were very common in Evo"s and dsm's. There are countless of Evo dynos with 500+awhp with a 50trim turbo

TheShodan

iTrader: (14)

That's to be expected considering it uses an entirely different compressor wheel

TheShodan

iTrader: (14)

"Greens" in the Evolution world would come close to that, but not more than 475-500. And I've owned Evolution since an Evo IV. They were definitely better than 57 and 60 trims, but couldn't do more than that.

Casey

iTrader: (5)

churches dyno 500whp?

TheShodan

iTrader: (14)

What about it?

LightningTeg

Sweet thread

MugenSpeclNY

thats pretty nice for 14psi. have a dyno graph/boost graph?

edit: compression/cams?

TheShodan

iTrader: (14)

I believe he has it on his thread he created. Search for "GT2871R at 353whp, what's next?"

TKERacer619

Stock exhaust cam, ITR intake and ~9.2:1 compression. Engine has a ERL superdeck and DRP Stage 5 turbo work including a reshaped combustion chamber.

MugenSpeclNY

Yeah i actually read that thread a while back.


Sandy fucked my area up... no power at the house(posting from work) for past 2 days and prob going to be another 3 days w/o it. No generator FTL

Turbo-GSR1287

iTrader: (1)

Would the GTX3576R or GTX3076R be a better candidate for a 600whp goal (on race gas) high 400s (pump fuel).

I just can't seem to dig up enough info on the GTX3076R on hondas

Muckman

iTrader: (2)

Id vote for the GTX3076.
TheShodan would vote for the GTX3576.

Tony the Tiger

The whole idea behind matching turbines and compressors is determining how much air the engine needs, and how much fuel it uses to sustain the power. BSFC is a common term for one of these aspects, and air consumption vs power.

More air and fuel means higher turbine requirements. Evo motors are notorious for needing rich AFR's (low-mid 10's AFR for those pushing big power on limited octane). It's a classic low compression turbo motor, so it uses a lot of CFM's to make any power. Along with rich AFR's, you can imagine that this engine loves a big turbine wheel/housing.

The Honda F20C, this motor is a perfect example of a high efficient motor that somehow withstands boost and lots of it. We've seen that this engine can run at big power levels even at high compression and pump gas.

High compression means lower air CFM consumption per HP, and has the ability to run at leaner AFR's due more complete combustion. F20c's generally require low-mid 11'd AFR even at high power levels on pump gas. With phenomenal mechanical and chemical efficiency, this may explain why some dude can make 500WHP out of a 50-trim turbo, or 700+ WHP out of a regular GT35R in an S2000.

There is no such thing as a "mismatched" turbo on the Garrett line-up. It's up to the user to choose the correct one for their particular build. For example, even the oddball GT2876R seems like a mismatch for any motor, but when used as twin turbos, they work well on smaller displacement V-engines.

I have a GTX3076R on my Evo 9, but it's a 10.5:1 CR engine with high lift cams (small duration) and other goodies. The typical Evo 9 shouldn't try maxing this turbo out unless you have some sort of race fuel and be able to signficantly advanced timing and lean out AFR's to keep exhaust energy down.

The dyno comparisons do not do the GTX3076R justice. In terms of transient response and how quickly the turbo flashes into boost, the smaller GTX3076R still behaves and drives like a GT30-based turbo. The GTX3576R, regardless of how well it looks on paper, still drives and feels like a GT35-based turbo.

In the Honda community, the GTX3076R is still a good turbo even up to 600WHP, if you really favor the spool behaviors of a smaller GT30-based turbine.

Tony the Tiger

Forgot to add, I also have the GTX3582R on my Integra this year... Here's one of my dyno plots with it..

GTX3582R with ATP T4 1.06 Divided Housing:


It spools up just like a regular GT35R, but has room for more power. I had it up to 700WHP, but the graph doesn't look good so I posted a cleaner looking chart instead. I get a full kick at 5200-5400RPM on the streets, but the dyno doesn't show the spool because I have a long runner front facing exhaust manifold that's still cold.

TKERacer619

My GTX3071r .63ar vs My GT2860RS .63ar

MugenSpeclNY

Thanks for posting tony!

really good info, much appreciated.

now for some noob Q&A to make sure i understand what your saying.

so a basic evo motor, loves bigger turbine/turbine housing b/c its a low CP/high CFM engine... This would lead me to think that the gtx3076 would be a better choice than a gtx3071 for a stock evo motor, correct? And for honda say a b18c, a higher compression engine(compared to evo), does not need the bigger 76 turbine, the 71 turbine would be a better match b/c it has less CFM consumption per HP and does not require the bigger 76 turbine for exhaust flow?

Am i understanding this correct? or did i totally misinterpret/piece it together wrong?

So if understand correctly... for a B18c engine(10.5-11.0cp), either the gtx3071/gtx3576, would be better choices(depending on goals) than the bigger turbine gtx3076/gtx3582?

im i generalizing to much?
if i fucked up, give me a brake, im trying to understand haha

Tony the Tiger

The GTX3076R has a larger compressor wheel (exducer). The GT30 or GT35 is the turbine wheel family. You had it the opposite way

You grasped the concept correctly though. Basically, a less efficient motor that needs more CFM to make the same power, will always end up liking a bigger turbine.

Some engines can run leaner due to better head/chamber design, small bore, well matched cams, good fuel atomization, etc.. AFR's is a big determining factor in exhaust energy and volume.

Higher compression ratio is an easy way to increase efficiency. The engine uses less air to make the same HP, and lowers BSFC due to more complete burn. The trick is to choose a compression that fits within your octane levels and power output.

Cams, phasing and overlap is another form of efficiency. Complete combustion has a lot to do with overlap, and how long you can keep the mixture inside the cylinders based on engine RPM. It will determine how lean your can run your AFR's safely at its specific torque band. Common examples would be the gains from direct injection and dual cam phasing, and how they sustain mid-high 13's AFR's even under full boost at certain RPM's.

There are no benefits from jumping over to the GTX3576R on a typical Honda build IMO, unless you are using another fuel like E85 or oxygenated race fuels with low stoich AFR's. By the time you can max out the X-76R wheel on regular pump gasoline, there is still plenty of room left in the turbine.

The Evo motor uses a lot of CFM and rich AFR's. It's both ways inefficient in comparison to a Honda. The GTX3576R was really designed for a stock'ish Evo motor.

For most Honda builds, a GTX3582R / GTX3076R gets my vote.. I would only choose a GTX3576R if I was doing a K24 low compression turbo build with a log manifold or something inefficient.

Muckman

iTrader: (2)

Tony I appreciate how detailed you are with your explanations. Do you really think the 76mm compressor will max out before the 30R turbine? We've seen dynos of the GT3076 vs the GTX3076 where very little power was gained from the MUCH more efficient GTX wheel. The conclusion was the turbine was the maxed out.

And what about boost taper - Doesn’t that reflect turbine restriction? I've tested the same turbo setup on both a low and high compression engine. And I can say we saw the same boost curve shape at about the same power levels (low vs high CR), even though we were at lower boost pressures. The conclusion again was the turbine was approaching its flow limitation.

So I would respectfully disgaree. I think you hit the limitation of the 30R turbine before the 76mm wheel is maxed. Isnt that generally true with any T3/T4 turbo?

Tony the Tiger

It's good that you brought that up Many instances, when a particular setup stops "gaining" power, it's difficult to judge what the true cause is.

For example, exhaust restriction can cause both boost drop/taper or boost creep, assuming the exhaust manifold and wastegate has good priority of course. Before deciding the true cause, you have to do a general assumption based on the engine setup and where the turbo is operating in its efficiency ranges (both turbine and comp). A turbine RPM gauge from Garrett is amazing for this. The below scenarios are more likely to happen on a turbo like a GT(X)3076R (or GT2871R, etc.. turbos with higher comp/turbine ratio):

Boost taper/drop could occur if:

- wastegate spring is too soft, causing premature opening, or internal WG too soft

- as boost is increased, compressor efficiency is dropping rapidly at the same time depending on where it lands on the map. The turbine could be keeping up, but the compressor loss steam (a boost gauge pre/post-intercooler could be helpful in gauging pressure drop too).

Boost taper/drop can also occur if the engine over-cammed with too much overlap, or has a poorly designed exhaust manifold/system for that given turbo. At some point, reversion is occuring with that particular cam (perhaps a fat N/A cam that is expecting normal overlap scavenging after VTEC). It could be way before the turbine is actually choking, but the cam opened up a passageway for exhaust reversion. Reversion will cause power and boost to fall off at higher RPM's even well before you physically max out the turbine. It's easy to spot this with a non-VTEC engine, but a lot harder with a VTEC setup with two cam profiles in the mix.

However, excessive exhaust pressure can also cause boost creep instead, assuming wastegate had priority and well sized:

- turbine is choking but not enough to cause reversion (mild cams), but at the same time, compressor efficiency is actually increasing. This occurs a lot on the billet wheels nowadays because the compressor wheel has a way wider efficiency range than their matched turbine wheels.

- this combination of increasing compressor efficiency and dropping turbine efficiency will cause boost to rise and creep up instead. The extra boost has nowhere to go and actually becomes creep. Because there is no significant reversion, the engine still continues to propels the turbine

- you can judge this by the torque curve, when the same ignition advance and AFR would result in a falling torque curve, although boost was actually increasing and creeping.

- Often times, when the turbine chokes, the engine runs hot internally. Most tuners will know that and end up running the car richer and retarding the timing. As a result, it exaggerates this boost creep even further. This may explain a lot of the boost creep issues that could be solved by advancing the timing.

It's hard to set these things with precise rules, because these relationship change on a turbo with different comp/turbine ratio, different cams or a totally different engine (e.g. Evo, Hondas, Toyotas, Nissans, etc..). A couple of basic checks for exhaust reversion is looking at the spark plug and its heat signature. An EGT or backpressure gauge does not show this though.

For example, I can check for excessive reversion if a set of cold NGK 9's would show a lot hotter than expected at low power levels but with a rich AFR signature. I would go through several sets of plugs if I was tuning a tricky setup with a turbo that is likely to choke and limited on octane. By phasing the cams differently for testing (but locking the AFR's, timing, and run the compressor at the widest efficiency range available) the color change of the plug gives me a good idea on when and where the reversion is occuring.

The other trick is to realize what the restriction is, and then tune around it. If the turbine is choking, I would "unload" the turbine by lowering the boost, run aggressive timing and lean out the AFR's to achieve the same power instead of the usual more-boost-and-less-timing approach. I would also close up the overlap as much as a I can without hurting power. By doing this, I can sort of cheat my way out of a turbine that is about to choke, and still make the most power I can get out of a given setup safely.

IMO, the GT3076R with an 0.82 A/R housing never gave me problems up to 500WHP on 94 oct on a 84mm B18C w/ 9.8:1 CR and ITR cams. I also had an F22C with the same turbo and a thicker HG (10.0:1 CR) up to 500WHP and ran well too. The same car eventually stepped up to a GT35R turbo with nothing else changed; although the dyno showed very little spool difference, the road evaluation was night and day -- the GT3076R spooled way better at lower RPM's and flashes way quicker. This wasn't a priority though because we turned it up to 650WHP after the turbo upgrade anyway.

Based on the turbine flow maps, the GTX3076R with 1.06A/R housing should have no problems at all up to 600WHP IMO... It's funny that building a setup for the best spool vs power vs engine size is the most difficult thing to do.