12.86 @ 119mph GT3076R @ 17psi T2 flange!

[Synapse Motorsport]

Logan this is part of my GT-R/BW spiel. I just took it from my BW FS thread, i have good access to these turbos. A good friend of mine owns a turbo shop.

Idk im always weary of those tests. First, they never seem to max out the turbos, which is where the borg warners always excel. Just about every BW will flow an extra 50 hp worth of air or more than the GT-R. In addition, on the smaller framed turbos the GT-R series do offer a better spool up time. However with the larger s3xx ect the advantages of the BB center cartridge are negated by the heavier design of Garretts wheels. The BW extended tip compressor wheels are by design considerably easier to spin, lighter for one, and less mass on the outside of the wheel with a taller inducer.

If you look at the large framed 1000+ hp drag turbos the BW will either spool up at pretty much the exact same time or faster because of this.

In addition, the s258 sports a much nicer compressor map than the s256. I havnt seen a single comparative test on the s258, i cant wait to compare one to a GT-R when i get the cash.

It also shows in that thread that the BW does exactly what im saying it does, makes more power as the boost level increases over the GT-R. They got pretty close to maxing out the GT-R, however didnt push the BW.

Oh, and its a GT-R dealer doing the test.

Modified by 480sx at 1:59 PM 2/17/2009

I just wanted to chime in and keep this based on facts and not assumptions. we pushed both turbos to the same boost levels, both were showing signs that they didnt have much left in them, power per lb of boost was starting to trail off on both. boost pressure and torque was dropping off hard in the upper rpms on both turbos. if we had a 35r to test that day i think we would have seen similar spool times, and a lot more power for the same and higher boost levels. the one big advantage the BW would have had over the GT-r turbos would have been racing in a class with turbo size limitations. the inducer on the s256 is smaller than the 30r and can obviously keep up with its power production.

This is my s258. (actually i finished the polishing job and it looks a lot better now, just an old pic)

Most if not all of the big HP drag guys have realized that the BW S series turbo has many advantages over the GT-R series, and have already switched to the S400's and larger. The BW S series has higher flowrates and surgelines than the GT-R series, making it a higher hp capable turbo. In addition to this, the Borg warner turbos are about 2/3rds the price of a Garrett GT-R series, and are rebuildable, unlike the Ball bearing turbos. The Garrett unit however will spool between 150-300 RPMs faster than the BW. For the smaller turbos, the difference is greater in the GT-R's favor. The larger you go, the gains are negated.

Here is a picture of 2 'Extended Tip' Borg Warner compressor wheels.





As you can see, the veins of the inducer/exducer extend out past the wheel. You can also see they used much less metal for their exducer. The tiny amount of metal on the outside of the wheel replaced a large piece of aluminum that is found on the Garretts Exducer. This allows for a lighter compressor wheel which will counteract the journal bearings tendency to want to spool slightly slower than the GT-R.

Compare the BW wheel with a Garrett GT wheel, shown here and you can see what im talking about.



See how the smaller fin(exducer) thats underneath the larger blades(inducer) is larger on Garrett's wheel? More rotating mass. Also, the BW wheels are taller and keep more of their mass to the center of the wheel while the GT-R's are shorter and fatter.

In addition, the GT-R series turbos use a smaller turbine wheel than a comparable BW unit. In another way of saying it, the BW turbine is a much higher flowing turbine wheel. This means that with the BW unit your back pressure(aka drive pressure) will be lower, your MPG's will be better, and your EGT's will be lower.

/end

If you have more specific questions just shoot me an email, its in my profile.

The GT-R is still a great turbo. I just want to do my own research before i believe there is a 400 rpm spool up time difference between the two turbos. In addition, my setup will be able to hit 600 hp eventually, so i plan on maxing out both my s258 and a GT3076R. Im gona go all out when i do the test, taking off both compressor wheels, weighing them, detailed pics all that good stuff. Will be a while though.

im not sure what garrett wheel that is but its not a gt35r or gt3076r wheel because they have a 6 fin compressor wheel, not a very good comparison to your s258. unless you have put both on the scale i wouldnt make any assumptions about mass comparisons. you forget the BW has a 7th compressor fin that has mass, not just the thin ETT.

you have a lot of assumptions about EGT, MPG, spool time, power productions, compressor mass, but no data to back up anything you have said. you can say we are GT-R dealers but we at least have the data to back up the testing we were asked to do.

and anyone questioning the durability of the GT series turbo this one tested had 20k miles on it already.

[480sx]

I just wanted to chime in and keep this based on facts and not assumptions.

Most of what i have written are hypothesis that i do plan on testing based on my knowledge of turbochargers. In addition, one of my close friends owns one of the better turbo rebuilding shops in the country and knows more about turbos that just about anyone. A very intelligent guy. Timsturbos.com

Simply because you do a single test and get X results does not necessarily make it fact. First, you didnt use the race cover for the Borg Warner extended tip compressor. Second, you didnt measure IAT's or EGT's at all, or at least you didnt display the results.

Compare the Borg Warner s256 map with a GT3076r, the BW supports a higher flow rate at higher pressure ratios. That is a fact.

In addition, an s258 IMO would make for a much better match up to a GT3076r.

if we had a 35r to test that day i think we would have seen similar spool times, and a lot more power for the same and higher boost levels. the one big advantage the BW would have had over the GT-r turbos would have been racing in a class with turbo size limitations. the inducer on the s256 is smaller than the 30r and can obviously keep up with its power production.

Again, as i have stated in this thread, the ball bearing CHRA advantage quickly diminishes as the turbo size increases. Its not so much about the overall mass of the compressor wheel itself, its about the moment of inertia. Basically, the weight distribution on the wheel itself. The GT-R series wheels have more weight on the outside of the wheels. Thats a fact, not an assumption. When i get the cash to pick up a gt3076r im going to do my own tests of my own.

im not sure what garrett wheel that is but its not a gt35r or gt3076r wheel because they have a 6 fin compressor wheel, not a very good comparison to your s258.

The comparison was simply between one Garrett wheel and one BW extended tip wheel. No, its not the best comparison. The wheel is a 50 trim t04b i believe, however it does display exactly what im talking about as far as the weight distribution and the design of the Garrett compressor wheels.

No ones questioning the durability of a BB turbo.

Like i say, i have plans to do my own dyno and street comparisons with EGT, IAT, everything. Again, these are more of hypotheses based on knowledge gained than assumptions. I present my hypotheses as fact, and that is my mistake.

They will be put to the test, i just dont have a grand to shell out for a GT-R right now.

[D-UNIT]

How come the GT2871r is rated at 450hp , And the Precision turbo my friend has w/ a 71mm comp wheel also, is rated at 700hp! pls explain.

[GTR PrYdE]

How come the GT2871r is rated at 450hp , And the Precision turbo my friend has w/ a 71mm comp wheel also, is rated at 700hp! pls explain.

The 71 on the GT2871r is most likely exducer(base of the wheel) size of the comp wheel, while the 71 your friend has, is the size of the inducer(tip of the wheel). Big difference.

[480sx]

^^ Yep

[sunnys14]

GT2871r will push 400+ hp if its pushed, depends on the housing also.

[kentuckyslider]

I ran a full second faster with 3mph slower trap speed with a GT2871R and stock cams and intake on my SR. I'm sure my car is a little lighter then your S14 but these are the 2 mods that made me lose .8 at the track....

4.36 R32 diff235/60/15 MT ET street radials launching at 7K

Consistant 1.6-1.7 60' and sub 12 second passes.

This can also be the result with a stock SR or KA transmission....2nd gear is the weak link. I'm on a S14 KA to SR transmission now and I have about 100passes on it for 6 hours and $200. I don't know how it's going to like 100 more whp from my HX35 and tomie cams put we are about to find out.

[kentuckyslider]

Oh yeah, I might as well chime in on the Garret vs BW topic while I'm at it. I loved my little GT2871R but I blew an oil line off my oil cooler and drove for less than a 1/4 mile and the CHRA took a dump in the next week. Then I owned a $1200 ash tray. I could have spent $950 for a new CHRA or go with my cheap holset HX35 top mount setup for the same price as a garret CHRA. I went with the Holset and it is bad a**. Cheaper, more durable, and I can rebuild it for $75. I will be a BW or holset customer from here on out. My next build will be a KA-T with either a HX40pro or a S300 series BW. Looking for 600whp in my next S-chassis. Obviously I'm into straight line performance.

BTW, how do you think my HX35 compares to the GT30R and the BW S258??

[ghx407]

Awesome ET and trap speed Sunny; your car looks sick.

[D-UNIT]

Agreed!