How many rwhp can it make if i got 19psi at 15degree @ 7000rpm with a 20b engine that is extended streetported with a greddy T-78 turbo???

I know that u peeps dont like the greddy T-78 on a 20b engine, but I hate the turbo lag..... so dont be hard on me

 

Look at the dyno comparison chart provided by catenet.

http://www.rotaryheads.com/dyno/

 

I didnt find anything that compares to 20b 19psi T-78 and whp.

 

I'm running a greddy t88-34d and I make 16psi by 3,000rpms on cleaned up stock ports. I think anything much smaller than that will chock the motor. Is that laggy?

-Destin

 

I made 587rwhp @ 7,000rpms. I had stock primarys and 1000cc secondarys and running low on fuel. When I get it retuned i'm hoping for 600 with the new rail and 1600's.

-Destin

 

How big is your exhaust A/R? 16psi at 3,000 rpm? I wouldn't call that laggy at all especially given the 20b's added punch down low when compared to a 13b.

 

Airflow is airflow.
Why does it matter if it's on a 20B or not?

On a 13B, the T78 would do about...what...450 to 470 at the wheels or so on a DynoJet?
Slapping the T78 on a 20B isn't going to make it miraculously make more power...

It would be very hard for a T78 to hit 500 at that boost level...I think...


-Ted

 

Mitsubishi turbos don't use "A/R".
They use some kinda area measurement like "7 cm^2" or something weird like that.


-Ted

 

Well, here's a T72 20B hitting 600hp @ 14 PSI.

http://www.catenet.net/graph.php?car...1&SUBMIT=GRAPH

T72 looks like a good match.

 

The greddy t88 uses a 72mm wheel, similar to the t72.

-Destin

 

And my exhaust housing is a 22cm.

-Destin

 

Here u can see more turbo info:

Turbo Compressor ..(inducer / major)..Turbine (exducer / major).....Notes

Turbonetics T72...(72.1mm / 102.4mm)...Q-Trim (68.4mm / 79.0mm).. .81 A/R

GReddy T88H (34D)..(69.7mm / 95.0mm)..T88 (72.3mm / 85.0mm)

GReddy T88 33D..(66.0mm / 90.0mm)..T88 (72.3mm / 85.0mm)

GReddy T78 33D..(66.0mm / 90.0mm)..T78 (65.0mm / 74.0mm)

HKS T04R..63-Trim (66.7mm / 84.0mm)..76-Trim (64.7mm / 74.2mm)......81 a/r

Turbonetics T66..(65.5mm / 91.0mm)...Q-Trim (68.4mm / 79.0mm)....... .70 a/r

HKS T51R KAI..(70.3mm / 94.0mm)..76-Trim (71.4mm / 82.0mm)


Ok! can u tell me how much power this turbos can make....and why the greddy T78 cant make more than 500hp on 20b?

 

Oh ok. I'll give you the secret on what turbo works best.

 

I made 760HP at 18-19PSI and 15deg
big street ported engine with 100mm piping and custom big intake.

 

Find the compressor maps...
It's all in there.


-Ted

 

correct me if i'm wrong, but a turbo cant make more hp just because it sits ona bigger engine... right?
but! there could be more N/A power on a bigger engine. But the turbo will not produce more air to the engine. So if a turbo can make 500hp on a 13B it could make 500hp on a 20B to... right? Or else the 20B will not need so much air to breath, but that sounds odd...

Am I right??

 

That was my point.
Airflow is airflow.
The restriction is the turbo, not the engine...

Eliminating really extreme cases, X model turbo on a 13B should produce just about the same power as on a 20B...



-Ted

 

Exactly. Except the power is alot more usuable on a 20b. The powerband is alot broader on a 20b and not as peaky as a 13b.

-Destin

 

Are those numbers from earlyer dynode cars?????
Or is those number from Greddy compresor map???

And those folks that got 500whp....was there target 500whp, or did they want more but the turbo couldnt make more, or they didnt want to boost more.?

If we dont have the compressor map then nobody can say how much the turbo is abel to make....
But I can see that supras has made more then 500whp and thats odd!

My point is not that a big engine makes more power with same turbo...I want to know exactly how much the greddy T78 can flow air thats all and then we can tell if it can make more power or not!

But remember that a engine that is all stock and can make 400hp with 20psi and u make it 50% biger, then the engine that is 50% biger will make 400hp with less psi.
So the turbo dont need to work att higher boost to produce more air flow, what it does is that it spins faster so it can deliver more air flow...

Now u can corect me if I am wrong...

 

Piston engines make more hp with the same given turbo's. Take the amount of air the turbine flows and multiply it by 10 and you'll have a rough estimate of what the turbine is capable of on a piston engine. Do the same for a rotary and then divide by 1.3 and you'll have a bit less. But good luck finding a compressor map for a greddy t78 or any other information posted by them on it.

-Destin

 

So u mean that eqution (30% less) works on all turbos???? then u do mean that there is only one turbine model for all turbos but they are in diffrent sizes???
Come on man I wrote that if we dont have the compressor map then we cant estimate anything....maybe the Greddy T78 is the worst turbo or maybe its the best one for the street/drift on a 20b engine???
What I see here is that no one have info about the greddy T78 33D turbo and no body wants to try if it can flow enough air.

I didnt say that I am going to find any compressor map.....I know that I wont find any compressor map.....

But how can u just say that it cant flow more then 500whp?
On wich circumstances do you base your answers on?

 

I never said it can only flow enough for 500whp. Read my posts and let me know where I stated that.

I have a greddy t88-34d and it's fine. I wouldn't want anything smaller than that. First time I drove it it surprised me how responsive it was.

-Destin

 

If XX turbo flows 70lbs of air then multiply that by 10 and you get 700. Divide that by 1.3 and you get 538. You will not get the same hp numbers from a rotary as you will on a piston engine with the same turbo.

-Destin

 

Yes! if it flows XX.lbs, but we still dont know how much it flows.

 

Yea. If greddy wasn't such bastards they would post some info on there turbo's. It would be nice.

-Destin