dupulup FTW!!! I'm getting a new race gas tune on my T-61 in about a week and planning to run 26 lbs, but I've been under the impression one could run up to 28lbs on the T-61. Planning to post it up on the forum if motor survives. It'll be on a really low reading dyno, so that should be fun trying to make comparisons! (LoL)

 

I've always heard 22 is the sweat spot with not much more gain the higher you go.

 

J-Rat- What type of port work are you flossin'?
T-61 BB Q-trim

+ Racing Beat Race Port

=

 

thats the same port I've got. How does that t61 feel with it?

 

See last picture in series above

 

The port I have is a proprietary one that Glen @ AZrotaryrockets built.

For comparison, I made 407 wheel at 14 PSI, so the motor FLOWS.

At 490 Hp, the car is FRIGHTENING... I turned the boost back down because I like traction..

 

I love your car...good luck on the sale
Its a great price

 

very impressive numbers. sure sounds like fun ... any video clips?

 

lol, nice!

he's not selling his car is he?

 

I know of a stock motor T-61 that put down 420 at 17lbs, and ran 11.1 @ 122. Is your proprietary port an average sized street port? Not sure how the comparison at lower PSI is evidence that the exhaust port is LARGE.

Your dyno graph shows precipitous torque losses relatively early. What does it take to keep torque production up a bit longer thru the range? I don't think that's because the T-61 is running out of breath up there. What is your turbine housing's a/r? Nevertheless, I do not doubt that the car is absolutely FRIGHTENING on the street.

I'm just a huge fan of the T-61 and it's my opinion that it's the best all around t-series hair dryer for street use. If or when I have to replace it, however, I'm going with a GT series and probably the A-Spec 500-R.

 

No, I am not selling.. Not sure where that came from.

 

At 17 PSI I was pretty much in the 460 range. I am not the turbo specialist, so I am not sure what to make of all the data, but as far as the AR goes, its a .96 turbine.

 

motor dowled yet? nice power! congrats

 

dowling is a waste of money IMO. I've talk to several pro builders that agree, but everyone has their argument.

 

Dowling is not a waste of time if you don't have the best tuning skills. If you do have great tuning skills then yes it would be a waste of time. I prefer to dowel just as an extra measure if I can prevent my rear plate from cracking hell all the better. Easier for me to replace a damaged rotor than it would be for me to port and replace a rear iron and would cost me a lot less. And doweling a motor is simple. A pic of extra dowels.

 

Dowling is not a majic force feild from poor tuning... it is only a way for the rear plate to transfer the forces of rotational acceleration to the rest of the engine.

Dowling is neccssary for anything more than about the 500-520 whp mark, at least if you want it to last in a racing senario for any length of time....

 

yeah either going to dowl my motor or get the stud kit, not sure. I think if your building an expensive setup that you want to last, every little piece of insurance is a good thing. At what, 250 bux if you get someone else to do it, it's not all that bad of a price.

 

i wasnt putting the question whether to dowl or not up for discussion, i just asked him if he had dowled it or not

 

I have a customer that made 513whp on dynopac hub dyno with T-61 @18psi using WI, The t-61 will reach its flow limits at about 17-18 psi on 13b at high rpm, increasing boost more than this will only give you more torque at mid rpm. I beat your boost had droped from 25psi to about 18psi at max rpm. this why your peak torque drops also as it follows the boost drop with rpm increase.
Good work on the power figures, it will be gd to see the new number with the race fuel.

 

Great info! How much do you think the whp would be at 18 lbs without the W/I tune? THanks!

edit- I still don't get how there is such a huge drop in pressure at high rpm. Don't the specs say it can flow up to 650 cfm? The power production is not demanding that much air, so why doesn't the turbo hold boost by simply increasing rpm with the motor? (it's late in the morning and I hope this question makes sense when I get up tomorrow (lol))

 

A lot less, Id imagine you will easily loss 50-100hp as you pull the ignition back and add more fuel to cool things down.
The t-61 is supposed to flow aprox 60-65lbs/min which equates to an aprox 660-700hp. The problem is max hp is made with aggressive ignition tune, but once boost is added to the equation the ignition needs to be pulled back to far to keep thing under control.

In most applications because of conservative tunes If you could measure the turbo flow of lbs/min you will find that the turbo reaches its peck at a hp figure that seem shy of the turbos true limits. Adding the WI will allow a more aggressive ignition and fuel tune that will more efficiently convert the lbs/min into raw hp.


BTW good nite haha

 

so your saying to keep the psi down to 17 or 18. I was planning on running 22psi but if that is out of it's efficiancy range than I will back it down to your suggested limmits.

 

No, run the 22psi that your thinking, This will give you a heap more mid torque. The t-61 performs well at high boost application, Its just that at high rpm the engine consumes a lot more than at low rpm. Since the turbo will reach its assumed flow limit of aprox 22psi at 6 rpm on 13b then after that point boost has to drop because the engine will demand more cfm at 7000 and 8000rpm .
A larger turbo like t-64 or t-70 will hold the 22psi higher in the revs, A t-70 could probably hold 22-25psi all the way to 8500rpm.

Efficiency and flow are two different things. Rule of thumb is....
small trim gives high boost efficiency.
Large inducers or large trim gives high flow.

High flow is what’s required to hold boost at high rpm.
High boost Efficiency is what’s required to give good compressor performance at hi boost.

Think of ot this way... Run twin T-61 on a 13b. The compressor maps of the t-61 show it favoring high boost applications. Running twins will allow huge cfm flow that will enable you to hold aprox 35psi at high rpm on your 13b. And the compressors will love it. 35psi is a walk in the park for a T-series type compressors.

 

cool, sounds great, thanks. Can't wait to see what it can do but building the hole setup to support one of your t70's or even mp gt45's maybe later on But not really sure if I even want to do that due to the slower spool etc... I think once I get this t61 where I want it I may start asking you about the t64, sounds like a pretty cool turbo as well. Thanks again.

 

haha i think you will be more than happy with the t-61, I know i was. Im fitting the t-64 now.... i hope i dont regret it.