I right know I have a PTE52 with there hole setup. Fully built motor, Stage 3 Vortec from McCoy along with his camshaft, Ported and polished uppers and lowers, 50lbs injectors, and 2800 stall 9/11. How streetable is a 72BB turbo. I don't go to the track alot it will mostly be driving on the street. How will the spool up be compared to the 52, alot slower? Can i run the 72bb with 50lbs injectors? Will it also bolt on to the truck with the ac installed? Anybody with a 72bb tat can inlighten me would be great. tell me the good and the bad about it.
How streetable is a 72BB turbo?
- Thread starter Syclone2882
- Start date
if you run high boost, you will run out of fuel with the 50s, at low boots, you could be ok
streetable - depends on the tuning, the buildup, and the stall converter
i drove a truck that had a 72, NON ball bearing, and had a great combo (ported Vortecs, 500+ lift cam, 3000 stall or so). The drivability was *great*. I was really surprised.
With your buildup, i think that turbo would work great. It will come down to the tuning past that point (chip calibration, your datalogging etc). That is assuming the stall is working well; 3000 or so stall should work fine in that buildup IMO.
streetable - depends on the tuning, the buildup, and the stall converter
i drove a truck that had a 72, NON ball bearing, and had a great combo (ported Vortecs, 500+ lift cam, 3000 stall or so). The drivability was *great*. I was really surprised.
With your buildup, i think that turbo would work great. It will come down to the tuning past that point (chip calibration, your datalogging etc). That is assuming the stall is working well; 3000 or so stall should work fine in that buildup IMO.
Brian,
I went 12.3 on 14psi with the 52, My goal is to run no more then 16 or 18psi. would the 50lbs injectors be okay for that amount of boost? with the BB will it spool better then the non bb that you were in?
I went 12.3 on 14psi with the 52, My goal is to run no more then 16 or 18psi. would the 50lbs injectors be okay for that amount of boost? with the BB will it spool better then the non bb that you were in?
The ball bearing will spool faster, no doubt.
As far as providing fuel from the 50s... hard to say.
That is a 72 series compressor map. A ratio of 2.0 on the y axis is ~15psi (at 15psi you are running about twice the pressure the atmosphere exerts on us, or 2:1). The x axis #'s are lbs/min of air. Multiply that value by 10 for the amount of horsepower supported. 15-18psi will supply 500-600hp, and will be in the turbo's peak efficiency "island". This is one reason I think this turbo will work well for you. As long as your converter stalls up well, and the turbo is a ball bearing unit, you should be happy. What intercooler do you have? That will play a part as well. The truck I tuned had the 512 cam, stage 3 vortecs, headers (dunno if that is good or bad for response), a 72 non ball bearing turbo, and a Dequick air-air. It responded *very* well and felt like a mid 11 second truck once it was tuned at 16psi. This truck ran a FAST ecm, so it was dialed in pretty well. Not saying yours won't be, but a custom calibration will only make things better. If I had your goals (11s on pump gas, low boost, very responsive, 50# injectors), I'd probably run a slightly smaller turbo, but running across a deal on a ball bearing 72 is something to take into consideration.
As far as providing fuel from the 50s... hard to say.
That is a 72 series compressor map. A ratio of 2.0 on the y axis is ~15psi (at 15psi you are running about twice the pressure the atmosphere exerts on us, or 2:1). The x axis #'s are lbs/min of air. Multiply that value by 10 for the amount of horsepower supported. 15-18psi will supply 500-600hp, and will be in the turbo's peak efficiency "island". This is one reason I think this turbo will work well for you. As long as your converter stalls up well, and the turbo is a ball bearing unit, you should be happy. What intercooler do you have? That will play a part as well. The truck I tuned had the 512 cam, stage 3 vortecs, headers (dunno if that is good or bad for response), a 72 non ball bearing turbo, and a Dequick air-air. It responded *very* well and felt like a mid 11 second truck once it was tuned at 16psi. This truck ran a FAST ecm, so it was dialed in pretty well. Not saying yours won't be, but a custom calibration will only make things better. If I had your goals (11s on pump gas, low boost, very responsive, 50# injectors), I'd probably run a slightly smaller turbo, but running across a deal on a ball bearing 72 is something to take into consideration.
hamrhead
Donating Member
For what it's worth, my Sy has McCoy's supermotor w/ Stage3 Vortecs, 512 cam, 1.6 rockers, KB Headers, KB Air2Air, FAST w/ 83lb. injectors, 72BB turbo with a 3000 stall converter. I think it's great on the street! It definitely idles a bit 'lopey' with this cam (which I like), and the turbo response is real good. Jerry McCoy said it runs better than Gilberts truck did. All I know is it flies! The time in my sig was with a 4# launch(1.67 60'), 15# into 3rd gear, where I turned it up to 19-20 for the rest of the run. Jerry figures a full 20psi run and the truck will be in the 10's. Which is what I plan on trying as soon as Winter breaks. 
*And at highway speeds, the boost response is killer! As the guy in the SS Camaro found out the other day. :wink:
*And at highway speeds, the boost response is killer! As the guy in the SS Camaro found out the other day. :wink:
I have a 76Q trim on my steet gn, with a 224/224 pte comp cam. It is totally streetable and is a nightmare for most cars I meet up with on the street in the Detroit area. My Sy has the same cam and turbo and will be unveiled this spring, I am thinking about going to a new pte 76gt it is suppose to be worth 50+ hp over the q trim turbo.
Anyway, the 72 is definitely streetable.
Mike B
St.Clair Shores,MI
Anyway, the 72 is definitely streetable.
Mike B
St.Clair Shores,MI
ghettosled
SYTY SUPERSTORE
you'll need a 3000 stall converter, and it will probably spool a little slower then the 52 (but like BG said there are alot of variables). With a good tune, who knows it might spool better then your current setup.
IMHO it will be worth it. With your build, it is begging for a 72
IMHO it will be worth it. With your build, it is begging for a 72
myclone
Donating Member
Ive been running the numbers on the below compressor map just to see if Ive been doing it right. Am I correct in saying that a pressure ratio of right about 2.60 is about the highest pressure you should run? Am I also correct in saying that at the above 2.60 pressure this turbo is good for about 625hp before it starts getting out of its efficiency "island"?
TIA for any thoughts/advise
TIA for any thoughts/advise
You are understanding it right, but it is difficult to find turbos that are run in peak efficiency all the time. Usually it's a compromise. You can map an acceleration run, or a 1/4 pass on a compressor map to see how well your turbo matches your buildup. Typically you'll have a horizontal line as you flow more air. If you can stay within peak efficiency (or nearly) for a good amount of time, you have a well matched setup.
Let's do a quick experiment. Tony's Syclone.
Before I look at the map (too late), raw data
Syclone (est 3800lbs) 10.7 @ 128, 27psi (or 2.8 pressure ratio) on a 72 (same map shown)
HP calculators say 610-620hp for this (we are just talking ballpark)
This is at the wheel, so we'll say 750hp at the crank.
So assuming peak hp of 750, guesstimate from his truck accelerating 4000-5500, the map is a line going from 550-750hp, or 55-75lbs/min at a pressure ratio of 2.8.
Damn, that put his truck right in the broadest section of the ~76% efficiency map. Nice eh? 8)
Let's do a quickie for my old Syclone buildup.
assume 3800lb 11.0 @ 125, 21psi (or 2.4 ratio), in a 63 turbo
Gives me ~570hp, at the wheels. Crank, we'll say 650hp.
Assume same scenario of engine acceleration from 4000-5500, hp goes from 450-650, or 45-65lbs/min at 2.4 ratio.
Here's the map for a 64, which I was told is the same map for a 63.
Based on my numbers above, I was in peak efficiency for much of the run, but at the tail end/high rpm area, it starts to drop off quickly. I saw my MAT temps increase some, as well as boost level dropping off during these passes. This was the main reason I stepped up to a 72 that winter after my passes, thinking that it'd support my engine better than the 63 did.
Let's do a quick experiment. Tony's Syclone.
Before I look at the map (too late), raw data
Syclone (est 3800lbs) 10.7 @ 128, 27psi (or 2.8 pressure ratio) on a 72 (same map shown)
HP calculators say 610-620hp for this (we are just talking ballpark)
This is at the wheel, so we'll say 750hp at the crank.
So assuming peak hp of 750, guesstimate from his truck accelerating 4000-5500, the map is a line going from 550-750hp, or 55-75lbs/min at a pressure ratio of 2.8.
Damn, that put his truck right in the broadest section of the ~76% efficiency map. Nice eh? 8)
Let's do a quickie for my old Syclone buildup.
assume 3800lb 11.0 @ 125, 21psi (or 2.4 ratio), in a 63 turbo
Gives me ~570hp, at the wheels. Crank, we'll say 650hp.
Assume same scenario of engine acceleration from 4000-5500, hp goes from 450-650, or 45-65lbs/min at 2.4 ratio.
Here's the map for a 64, which I was told is the same map for a 63.
Based on my numbers above, I was in peak efficiency for much of the run, but at the tail end/high rpm area, it starts to drop off quickly. I saw my MAT temps increase some, as well as boost level dropping off during these passes. This was the main reason I stepped up to a 72 that winter after my passes, thinking that it'd support my engine better than the 63 did.
myclone
Donating Member
Welp, least I am reading the comp maps right.
More questions…. Using the below map would it be correct to say “to make ~650hp more efficiently (as far as the turbo is concerned) would require a pressure ratio of 3.0 but… youd would need to kill of some of the airflow at lower boost to stay close to the efficiency island (using the cam and/or timing?) at lower air flow”? Im assuming this by drawing vertical lines from the lower lb/min scale upwards through the map and noting the intersecting number horizontally. Does what Im asking make any sense or should I try to splain it another way??
More questions…. Using the below map would it be correct to say “to make ~650hp more efficiently (as far as the turbo is concerned) would require a pressure ratio of 3.0 but… youd would need to kill of some of the airflow at lower boost to stay close to the efficiency island (using the cam and/or timing?) at lower air flow”? Im assuming this by drawing vertical lines from the lower lb/min scale upwards through the map and noting the intersecting number horizontally. Does what Im asking make any sense or should I try to splain it another way??
I know what you are trying to ask, but from what I've seen, you don't worry about that. You are saying that if you wanted to make that 650hp at 3:1, let's say at 5500rpm, that you'd try to make 500hp at 2.4:1 ratio, maybe 4500rpm, to keep it in peak efficiency (and avoid compressor surge).
Would it be worthwhile to scale the boost, if you had all the data needed to make such a calibration possible? I don't know. That's a question I'll pose to the experts I work with. Possibly you'd stay in peak efficiency at the lower boost, but you'd make more hp/tq at higher boost while still at a less efficient turbo condition.
Would it be worthwhile to scale the boost, if you had all the data needed to make such a calibration possible? I don't know. That's a question I'll pose to the experts I work with. Possibly you'd stay in peak efficiency at the lower boost, but you'd make more hp/tq at higher boost while still at a less efficient turbo condition.
dave, i think what your seeing is that at 650hp, a T63 would be better suited for a small displacement (4cylinder) drag car running BIG boost. where as a T72 would be better suited for a syclone since we will make more HP at lower boost levels.
also, i dont see how scaling the boost would affect what dave was asking about. the way i see it is you would want to affect airflow without affecting boost. so...... basically designing a motor around the compressor map of the turbo you wish to use? is this right?
BTW. this is a GREAT post to put into the vault. i feel like i learned something today other than how another chicks boobs look.
e
also, i dont see how scaling the boost would affect what dave was asking about. the way i see it is you would want to affect airflow without affecting boost. so...... basically designing a motor around the compressor map of the turbo you wish to use? is this right?
BTW. this is a GREAT post to put into the vault. i feel like i learned something today other than how another chicks boobs look.
e
Tommyquest
The Member's Member
This is a good thread. Lot's o' good info