RacerXtreme7

iTrader: (2)

Like the tittle says, whos running a .84 a/r divided turbine housing? Reason I ask is I'm going full T04 (to4e 60 with a P trim turbine) and I cant decide to go .84 or 1.0 on the hot side. I'm sure Im gonna hear go 1.0, but Im looking for a quick spool, I'd like 7-10 psi by at least 3000 to 3200 rpm's. My target max hp level @ 8500rpms is any were from 350-400 at the wheels. I'll be running a series 5 large street port with series 6 upper manifold, stainless divided turbo manifold, IC, Wolf 3d, etc. etc. I know the .84 will give me excellent spool but whats the approximate hp level max before its the bottle neck? I'll be running a very good high flowing external wastegate. There getting 350 whp out of hybrids with the tiny stock turbine housing so I would think 400 out of a to4 .84 would be sufficient for 400hp, I just want real world answers from people who HAVE DONE IT. I know the 1.00 will be more then enough for 400hp but whats the spool characteristics like?

Thanks, ~Mike.......

turbostreetfighter

the .84 will do nothing for you and believe it or not a 1.15 will spool faster due to the velocity of the exhaust, especially since you have a street ported engine. i am confused about the a/r' you mention..does that turbo use a t3 hot side? if so then you may want to go even larger. even if you get away with it on the dyno it will not work on the street/strip , save yourself alot of grief and go with the larger hot side.


MWW

1FastT2

iTrader: (1)

I beg to differ. Im running a TO4B with a 0.84 hot side with a P-trim and a 60-1 compressor and am quite pleased with it. It pulls way past 8,000rpms without any noticable drop off running 15psi of boost. I also have a quite big street port. I was thinking of changing it out with a bigger A/R just to see if there were any differences. I'm pleased with the turbo and would recommend it to anyone who asks.

RICE RACING

Be a man ! Use a 1.32 a/r rear housing. You know they have invented these amazing things called "gearboxes" that actually allow you to use the power range of the engine as it was designed

Seriously though, I imagine that the 0.84 will choke the F*CK out of that engine at any revs above 6k. Sure you can rev to 9k still if you wish but it will be running on a combination of exhaust fumes and fresh air ! This small housing may work with std exhaust ports and street port with the opening timing not altered from stock, anything more than that and it will be a detonation time bomb waiting to go off once you start pushing over 400bhp especially on pump gas.

Jesuscookies

iTrader: (1)

question. what is going to give you the quickest spool rate. 1.0 or an .84?

If most of the driving is being done in the 2500 to 6500, with the occasional 8500, RPM range wouldn't it benefit him to have a smaller A/R?

I am asking this question because Iam in the same boat as racer extreme7.

I have been reading map after map, and studying those damn A/R rates. None of it is telling me if I am going to have full boost by 2500 to 3000 RPM though.

Why not just use the straight 60-1 and bring the hot side down to .84 for quicker spool up?

RICE RACING

Jezus, man if you want full boost by 2500 or 3000 rpm you need twins ! If you want max power up to 6k then you are realy wasting the potential of going to a large single turbo.

You maybe want a hybrid or something like that instead ?

Jesuscookies

iTrader: (1)

Okay then, based on what I want to do, I was thinking that the straight 60-1 or T61, would be the right turbo.

Are these good choices? Would a different turbo be better?

What A/R should I go with?

What Trim?

when is the soonest I can expect boost to come on with any of these selections?

RacerXtreme7

iTrader: (2)

Keep in mind here I'm NOT looking for 500 + hp, this isnt a drag racer, its a street car that I will occassionally auto cross. I'd like good linear throttle response. I also want 400 hp when I turn the boost up also to spank those pesky stroked / bored Cameros in my area . I'd love to run a 11 sec. quarter with a streetable car.

I thought I was on-track, according to what 1FastT2, im spot on, but I'd still love some #'s of real world experiences....... 1FastT2, what kind of response are you getting from that combo since its very close to what I wanna run? Whens boost come online? Give rpm vs. boost.

[QUOTE: turbostreetfighter] the .84 will do nothing for you and believe it or not a 1.15 will spool faster due to the velocity of the exhaust, especially since you have a street ported engine.

I respect your answer and your knowledge given your a racer and make considerable hp levels. But being a engineer, I tend to think that the smaller A/R housing would have a FASTER exhaust velocity then the larger A/R. Hense smaller housing = faster spool due to faster exhaust energy. Now unless the logic is that the engine is exhausting so much exhaust energy that the .84 chokes it to a given exhaust velocity and flow, that going larger allows more energy to flow there by increasing both flow and velocity, but I honestly do not think that .84 T4 housing is that restrictive. I mean come on, seen those tiny stock housings and the hp levels from a hybrid?

[QUOTE: turbostreetfighter] i am confused about the a/r' you mention..does that turbo use a t3 hot side?

These are standard Garrett T4 housings, maybe your used to hearing the non-divided a/r's, which would be .84, .96 etc. I will be running a full T04 / t4 turbo charger.

Still undecided......anyone running a 1.0 divied P-trim 60 trim T04 that could describe to me the responsiveness of it?

amemiya

first of all If you want your cake and eat it to you have to go with a GT series turbo like the GT35/40 would be perfict for what you want. I have a friend with a 60-1 with .84 A/R, yeah it spools up fast but he only made 325rwhp another friend has a 60-1 with 1.15 A/R and he made 407 rwhp. if you want the best of both worlds get the GT35/40 you will be happy. full boost by 3500 rpm and 400+ hp. If $1400 is to expensive that you are going to have to lower your standards cuz those are your choices. well I hope I have helped. good luck man

1FastT2

iTrader: (1)

I only had it dynoed at 8psi so far when I first got the engine broken in and I had not turned up the boost yet. The car had 270rwhp with 8psi. I since turned up the boost to 15psi and was extreamly impressed with the amount of HP gained from the extra boost. I also ran an 11.81 with 14psi. The boost comes on realitivly quickly reaching full boost by 3,500 - 4,000 rpms in 3rd gear. Hope that helps you out, if you have anymore questions ask away.

Jesuscookies

iTrader: (1)

Where can I find out some more information on the GT35/40 Turbochargers?

turbostreetfighter

why in the hell do you care what boost you make at 3k rpms? if you are full throttle where do you shift at....5k? if you are shifting that low with a ported engine why did you waste the time porting? porting is not done to increase midrange it is done to increase upper midrange and high end so why not match the turbo to the port? also if you are only running 8-10 psi you can pretty much run whatever housing you want but you suggested that you wanted to make around 400 h.p. and the .84 is going to choke the engine....it is called BACKPRESSURE!!! and that is the rotary enemy on ported engines with overlap. as Rice said, on a stock motor you can get away with it and it will probably work ok but if you take a ride in a car with a 1.15 or even 1.3 and then turn around and in a car with a .84, the MAD power the bigger housings make will make up for the 1500 rpm later spool up! be a man, dont go against the grain!!


on my race car i am able to make FULL boost (30 psi) by 5700 rpms and this is with a T-76 and a 1.3 turbine housing!! since i dont shift until 9500 i am going to a larger setup.

MWW

680RWHP12A

i use a .81 on the exhaust side.... 28psi, no problem.....i had a .96 bot the problem i had was the engine would fall off boost between shifts, causing too much turbo lag....slower et's.... why use such a large hot side with a p trim??? the restriction is going to be the p trim at high rpm's so you should definatly go with a smaller hot side!!remember... you want 'useable' power !!!!

sub-zero

Turbostreetfighter, I have a large street port and just bought aTurbonetics T-72 BB with a small .83 or something hot side. I have to pick a larger housing and was just wondering what You would recomend for A/R and should I go Tang/divided . I dont care to much about lag and will run moderate high boost with some water injection. I keep reading and hearing dif. things from dif. People but thought a .96 might work. Is that to small of a housing?

Thanks

turbostreetfighter

i went 9.38 with that setup at only 22 psi and that 'p' trim has a clipp which also reduces BP. is your motor bridgeported? how big is your exhaust port? my car is automatic with a transbrake so i have to make sure it gets 'on tha brake' and since it is auto there is no boost drop between shifts so once it is spooled it stays spooled!!! i now realize that the 'p' trim is the restriction but when i first started the project my 'grunt' engine was not as healthy as the one in the car now and it worked fine but as i increased overlap it became the restriction which is why i am going to twins now, if i go with the larger 'q' trim it will not spool fast enough for the .400 (pro light). on my street kits that go on ported motors i use .96 'p' trims with the clipped wheels and they pull to 8.5k with a 4k full spool and a 1:1 BP ratio. i find it hard to believe ( not calling you a liar, just judging from my experience) that you make that much power with only a .81!!! the hondas run 'q' trim .81's and i KNOW you have more exhaust than they do!!! have you measured your backpressure at 28 psi?


MWW

RICE RACING

**** me ! That is unreal

I have usable power ! Full boost by 5k and holds to 8.5k, with very minimal back pressure, on the engine.

I shudder to think what the pressure ratio is between your exhaust and your inlet.

how much NOS were you using on the 680rwhp run ?

turbostreetfighter

halarious Rice!!!! i was thinking the same thing he must know something we dont. or has almost no overlap!!





Sub Zero since you have a BB turbo i would suggest the 1.3 divided (i dont use divided so i dont know what the exact a/r is ). what turbine wheel do you have?


MWW

680RWHP12A

no nos....thats why i use a small hot side., my turbo is ball bearing also and its a Q trim... it still takes 4,500 to make full boost and is still pulling when i shift at 9600 rpm's! i havent checked my backpressure yet but i plan on checking it soon...p/s your car would NOT come on boost slower with a Q trim either the wheel design allows the boost to come on faster due to having more surface area on the blade for the exhaust to push on...

680RWHP12A

pss my motor is bridgeported!!! check out my dyno sheet at www.rotaryshack.com/dyno

turbostreetfighter

but weighs substantally more and it takes more energy to turn a larger diameter heavier wheel no matter what it flows!!


MWW

680RWHP12A

How much power did your car make? (turbostreetfighter)

turbostreetfighter

i have got to get my kid asleep and will catch up with y'all tomorrow.

680 what comp wheel do you use? your dyno sheet shows that you are dropping off at around 8500 and i am just wondering why, especially on an inertia dyno i would think it would keep rising with that small a/r. i have noticed that even on my car i got 8 psi less BP on the dyno than on the track. what kind of ET/MPH does your car run? also a 5200 i notice that your angle changes slightly and starts to get rough, i would definately like to know what kind of BP readings you have.


MWW

turbostreetfighter

i cannot get an accurate dyno reading due to my 6400 stall convertor that is non lock up, i dont know if you have ever dyno'd an automatic but it is quite useless.i do not believe in dynos for anything more than just making sure the car does not blow up!! the trackis my dyno!!!! i did run 119 in the 1/8 and the car is 2295 lbs so the math comes out to around 645h.p. and that was with horrible BP and anything over 23 psi the car would slow down.

680RWHP12A

my friends supra is automatic and his dyno #s were around 800 whp.... his car goes 940 et's.... he has a .81 housing and an "r" trim BB with a 80mm compressor also uses nitrous (80 HP) ps...do you have any idea why my graph might have the surge around 5000rpm, we tuned the fuel up/down with no change to the dip...the injectors all come on at 12psi, so we are well past the staged area....its a Haltech f9....thanks

RICE RACING

Well the numbers figure out to.......

795 odd bhp
8900rpm
IC eff 85%
VE 91%
BSFC 240 g/hp/hr
std temp pressure corrected
A/f in the 11.0 region.
28psi boost

I am making some guesses but it seems logical. That is excellent power, I think you would make a bit more with a larger a/r rear, but anyway you gotta be happy with almost 800bhp from a 12A without NOS !

I assume you are into drag racing ? give us some details, does it perform the same on the track as on the dyno run? I am a drag racing novice but with that amount of BHP it would pull some serious MPH in anything smaller than minibus or SUV !