Xperience

I have started piecing together my turbo kit for my B18C. I will be doing autocross and track days with the car. Power goals are 250-300 daily driven. Stock internals with mini ram turbo manifold. What would be better? Disco potato or T3/T04e with .63 A/R?

TheShodan

iTrader: (14)

The disco potato is a smaller, more responsive setup that can doe about what you're asking for quickly and with more durability when run with the correct restrictors and water lines. Most T3/T04E Garrett 50 trims on the market don't have that option, so to me, that alone for the purpose of the car is one of the main reasons as to why to go for something similar to the potato, and not the 50 trim.

You're using this car for 3 different purposes, all which are rather abusive to the oil and turbocharger in ways a drag strip never sees. In your particular case, I'd step it up a little bit and go for either the GTX2867R or the GT2871R for the B18C1 over the disco potato. Those two turbos give a bit more midrange for the street use the car will see and still be able to perform well on the circuit and even AutoX, (although you won't be out of 2nd gear much while cone dodging)

These two choices will also be a bit more useful to with the boost pressure needed considering you're in a 91 octane state. Your goal can still suffice with this.

Now, don't do anything stupid like putting a .82A/R turbine housing on it, thinking you can go " a bit further later". Considering that these turbos use a 56mm inducer turbine wheel, you'll just destroy the characteristics that you're looking for in these turbos.

So the answer to this is..... Neither.. For the B18C1, the GTX2867R and GT2871R in a .63 A/R T3 (or .86A/R T2 if you're staying internal gate) would be your best bet.

Xperience

This was a very nice reply. Thank you very much. Now I have my options cut down to 2 options. Now it's time to start saving! Thanks again for the help!

DC_Legacy

Shodan.....these turbo's are within what I've considered the "ideal" range of turbo's for my goals with the exception of one more (the day I manage to upgrade to the "ideal" turbo setup that I want) For a 1.6-1.8L though, would the GT2876R be too large for a setup that aims to make for a quick responsiveness for street/ DD use with an overall WHP goal of no more than 375? Just curious why this wasn't listed in the considerations unless it only shifts the powerband upward too much making the midrange too much of a compromise over peak power.

The exhaust manifold choice will most likely be a simple inline pro stainless manifold on either a B16 or possibly as big as an 89mm crank....

m4xwellmurd3r

I honestly think the gtx2867r is the PERFECT turbo for a responsive daily with a peak power around 375. Ive eoughly plotted it and most of the rpm range is in the meat of that compressors efficiency range around 15-18ish psi, more than enough to make that kind of power iirc.

Is this correct theshodan?

DC_Legacy

For a B16 or B18 vtec, or both?

Also, found it funny that this turbo made it in the "Urban Dictionary"

http://www.urbandictionary.com/defin...disco%20potato

m4xwellmurd3r

Whoops I miss typed. Its 2867 not 57

DC_Legacy

Yeah I figured thats what you meant

DC_Legacy

If you don't mind my asking, when you plot any compressor, what Volumetric efficiencies are you going by?

The usual Garret turbo tech math says to use 90-95% for modern 4 valve heads and considering VTEC increases this further ive always used about 97% after full boost but some times using NA VE's for plotting non ballbearing turbos gives me seemingly inaccurate figures unless im targeting the spool start rpm wrong.....

riceball777

The disco potato would be much better for yours goals. The 50trim is a much bigger turbo. Hell, I made 501whp with my old garrett ball bearing 50trim.

But if I were you I would go for the gtx2871r.

turbomaniac

disco - potato (garrett GT2860RS) is the proper turbo for your application, because it behaves better at low pressure and has smaller lag.

for stock internals i dont suggest more than 7-8 psi pressure and the disco-potato can work very well at this pressure.

t04e is a journal bearing turbo much bigger than d-p und it doesnt behave so well at 5-6 psi that you must have in order to keep your internals safe

TheShodan

iTrader: (14)

Ok. I'll just break it down like this: Please remember all of these use a 53.90mm exhaust wheel diameter, so the changes are subtle but focused more on a .92VE of a standard VTEC B16 head with at least GS-R camshafts for 320whp - 350whp. 375whp is more for the GT(X)30 series in the smaller compressor wheel exducers under 71mm.

But m4xwellmurd3r is on the right track here, though 375whp on a GTX2867R is a bit on the optimistic side. For 375whp, I'd look to the GTX3071R or TR3030R.

I'm looking at this on multiple purpose levels, which is why I'm making these calculations a bit on the "tight" side. Most people tend to look too much at the street and not enough for the gearing and purpose that he's looking for. In addition, I've always thought it best to stay internally gated with a CORRECT and proper boost controller. No BBG, NO super duper boost.

If anything i'd simply change to a turbosmart internal gate that has the adjustments he'll need in order to be more responsive without all the electronic gobblty gunk for autoX.



I like these better than the standard internal gates that Garrett Provides because of their simplicity of adjust-ability for that type of racing. With these sizes, bleeding off a lot of boost with a larger gate simply isn't needed because he'll be running enough pressure to keep an even boost ramp curve and hold onto better midrange, as long as he doesn't get an exhaust manifold that allows too much exhaust energy volume, like a Kooks. He can stay REALLY simple on a T2 or T3 platform tubular log, (or dare I say even cast) for these turbochargers as long as he gets the right downpipe flanging for his downpipe.

Its like having a GReddy styled setup without the GReddy name, and all the newer benefits of today's turbocharger choices.



B16:


Cast wheel
GT2860RS "Disco potato"
GT2876R

Newer Design
GTX2860R
GTX2863R

B18C (which accounts for a bit better use of the increased stroke that he has)

Cast Wheel
GT2871R
GT3251B Journal bearing if more street

Newer Design
GTX2867R (for the smaller side)
GTX3067R (Notice I did not say GTX3076R, BIG DIFFERENCE)

Schister66

As soon as you mention "no more than 5-6psi" everyone tunes you out. For those of us with actual experience, we know better than to suggest goals in terms of psi like this. Also, if you're going to buy a GT28rs and run it at 7psi, you may as well save your money and buy something non-ballbearing. If you actually look at the GT2860r compressor map, you'll realize that 1.5pr (~7psi) is BARELY on the graph.

OP: I think you already got your answer courtesy of TheShodan

turbomaniac

unless you didnt notice this guy wants the car for track days.

a stock internals b18c (200hp) with stock CR, disco potato and 7 psi would make about 320hp.

Do you think this car will last track days at 320hp stock internals?

from what i ve seen shodan knows the hell what he is talking about but some others express other people's opinions...

the journal bearing turbo has a lot more lag than ball bearing and has way worst behavior at low pressure.

turbomaniac

i believe that the recomandations must have a car use guide, (ie for stock internals, for ultimad drag road etc). I can see that your recomandations seems to fit to a 500hp street racer, and i agree with them.

these recomandations cant be applied at stock internal mod or extreme street race mod.

i believe that for extreme street race a GTX3071R or ball bearing PT5858 CEA must be used for b16,

GTX3076R or BB PT6262 CEA for b18

GTX3076 for b18

DC_Legacy

Indeed if I remain with the 77mm stroke I have already ascertained a set of GSR cams so the B16's are out but maybe ITR's I will consider depending on if I hit any limits with these......my goal is to keep compression between 10:1-10.5:1 with the least amount of boost needed for a quick streetable setup that will be fun and last with the end goal of 325 at the least to 375 at the most I am aiming at now...

Your a true scholar sir!

TheShodan

iTrader: (14)

We'll just agree to disagree, but I wouldn't use ANY of the above examples stated , even size-wise for the intended use. Those sizes you listed as examples are just too large for the effective pressure ratios that the OP is going to utilize for their type of racing.

I actually go by several different criteria, including but not limited to Cylinder head VE, engine displacement, effective turbine efficiency range, (to match proper turbine wheel size), Compressor wheel exducer to turbine inducer ratio, type of fuel used (Simply as a guide to know what effective boost pressures the person may be using for the purpose) , CFM of the engine at about 13 different rpm points for a given boost pressure , and type of racing for a given use. I'm not using magic here, just proper matching for the type of use the owner is seeking.


I'm Sorry, but if you think I'm using the kind of logic for a "street" car based upon the examples you listed, you're definitely off base.

TheShodan

iTrader: (14)

Stop being afraid of boost pressure. That is not what kills engines here. Its the engine's lack of ability to resist knock and detonation (too much air and not enough fuel ) with the increased cylinder pressures that tears stock components apart. Not "boost". This is why its not really the best idea to try and tell your tuner what boost pressure level you want. If you're not familiar with the way that particular turbo will behave with that engine, you may be doing yourself a disservice without knowing it. Let the tuner do his/her job with fuel and ignition timing. If he or she is that good, they'll know when to stop appropriately, because they can see that fuel/air/ignition information as they're tuning that car , and will have already asked you the right questions prior to getting on the dyno. .

Adding static compression is a great start to help with the goal of recovering exhaust energy quickly in between shifts, and reach your effective compression more quickly, but don't look at is as the only way to use as little boost pressure as possible, or you still may wind up outside the efficiency range of the turbocharger that you're selecting. (meaning you're running too low of a boost pressure for a given turbo to work properly.. you still may experience some lag where you don't want)

Contrary to popular opinion, turbochargers like pressure, so to continually limit them down to below their effective range can easily affect the way that you want the turbo to behave; which is in effect, a larger engine with more torque than what the engine can originally give.

For the type of racing that you're doing, torque is what matters more than even power. You can have both, but that's the challenge in finding the right balance. Other areas like camshafts and even transmission modifications can help, but in this case, there's no reason to focus too hard on the camshaft for the levels you're trying to achieve here; especially in autoX where you'll barely get past optimal VTEC points anyway.

375whp is for the days on the street. Just be prepared either way to increase boost pressure on those days. But to think you'll just be at ONE boost pressure level to satisfy all these requirements of AutoX, circuit, AND street use, won't happen. (This is exactly why people pick a turbo too large for their application 70% of the time, so that they can "grow" later and not have to reevaluate their turbo choice. *snicker*). This is where your driving ability and supplemental equipment really have to come into play here.

TheShodan

iTrader: (14)

But that's not just because of the bearing package. Both the configuration of the compressor/exhaust wheels and the right balance ratio between compressor/exhaust sizes are what make the bigger differences. Better "spool" up from the ball-bearing package is more of a by-product than its initial designs.

I've had plenty of people with T3/T04E 50 trim journal bearing systems get converted to a ball-bearing cartridge, and not ONE bit of response was increased using the same boost pressure level in one gear. Recovery response was only slightly improved, but the biggest gain was the durability of the cartridge because it was less dependent upon the oil to both cool and lubricate the center cartridge.

This is why I like even journal bearing turbos to use water lines (as does the OEM), because it allows the oil to lubricate that turbine shaft effectively without being subjected to as much "coking" effects that could occur without it. The oil then doesn't suffer as much thermal breakdown, and can continue to lubricate the shaft properly even after shutdown, where the effects of "coking" are highest.

m4xwellmurd3r

^^^this guy always has good stuff to say.

I completely agree with everything you said. On my build im dead set on getting a gtx2867r. I want under 400, boost to build up decently early, with a broad power band mostly for daily driving and the occasional mountain sprint. Im running an 81.5 ls engine, with a mildly ported ls head with decent cams, plan on running a skunk 2 pro intake, an spfab quick4 manifold.
I estimate ill be in the mid to upper teens for boost, which from the map should put me right around the widest efficiency area without running out of puff too high. Idealy id like around 350-380hp, but tuning for torque is more important to me.
I dont want more power. Itll be a daily, and with stock sleeves I dont want to push it.

Theres still a lot of variables, I havent even begun to look at intercoolers

Does my setup sound like itll deliver what I want?

redlinetuning

Boosted fwd with high hp are exciting to play with. Depending on the gear ratios, autox will be in either 2nd or 3rd. But you will have issues with traction, so good tires will be necessary.

I was using a t3/t04e 50 trim before I upgraded and loved the low end power/torque band because it was quite responsive. However i had this in a top mount manifold configuration.
I'm in the process of rebuilding but my pte5831 .63 A/R is more than enough power. She makes ~260-270 foot-pounds of torque on a 4.7 LSD equipped transmission.

wantboost

iTrader: (2)

No gt28 based turbo will make 300+hp at just 7psi... you're well above 14-15 just to break into 300.

Learn the motors and you'll know a proper range to suggest for a given power production. boosted vtec motors have VEs of well over 100%

And anyone here with turbocharger experience knows you run whatever psi it takes to make the power wanted. not stay at 7 because it's safe... if a tuner can grenade a motor at 7psi on a small gt28xx turbo then he probably sucks at it and needs to quit.

turbomaniac

i will speak with facts:

this is a b16 a2 with GT3071R, 9-1 cp pistons and eagle rods, completely sock head (not even ported), sstock throttle and inlet manifold. I made all the exhust and i did the set up for the entire mod my self. pressure is 15 psi..
at 4300 rpm we have almost full boost and 15 lb/ft torque.


i cant see why a GTX3071R is big for the b16 engine if the target is an 600hp sreet racer (assuming that GTX3071R has better response and flow than GT3071R)... of course i agree that for a time attack car or a stock internals car the GTX3071 is big.

And also why i have to use a GT2871R turbo to a b16 engine to produce 500 hp at 30-35 psi (and have increased inlet temperature and useless low and mid rpm torque), and not have the 500 hp with a GTX3071R at only 20-25 psi (and lower inlet temperatures)?

IMO the torque and the high inlet temperature (if we assume that the AFR would be ok) kils an engine so i believe that we have to focus to that.

turbomaniac

i agree i made wrong for the 7 psi (wrong convertions)

for b18c and B18c5 (not any other b18) at 9 psi, 76mm exhaust and complete stock engine GT2860 will make about 300 and GT2876 will make about 330.

try it for your self....

look guys i am not trying to be a smart *** or sg else.

i just present the things i know from my little expirience without telling lies because i believe that experience and knowledge must be free.

if i have done wrongs each one of us can judge me and keep only what he thnks its right.

i cant force no one to do as i suggest, each one has free whill (or better free wheel.. lol)

turbomaniac

the water cooling to journal bearing is sg i never took seriously but i was wrong as i can see now.

have you mesured how much is the burden to the cooling system if we use water lines to the turbo? Do we have to use biger radiator ? this is sg i always had question and never got answered