Less hp than I am hoping for, but at 15 psi of boost here's what it predicts.



At 20psi,





[Modified by Monty, 12:27 PM 5/16/2002]

 

Am I reading that correctly over 1300 pounds of tourque at 2500 rpms :eek: I am buying stock in BFGoodrich today :chevy

 

Yes, that's what it says. The turbo stuff in DD2000 is kind of weak, and I don't know how accurate it is. I'm not even sure if I'm entering the data in right because I'm kind of confused about the Flow input. DD2000 says it's for CFM, but the input parameters seem like it's really wanting lbs/minute. My turbo's (60-1 compressor) are rated at 900 cfm each, or about 60-65 lbs/min.

Honestly, I hope it's wrong, I don't want that much torque that low, i'd like peak torque to be aorund 4500 rpm and peak hp around 6500-6800 rpm. I'd like to get around 900 ft lbs and around 1200hp, but it's predicting just the opposite.

 

Monty, your turbo input data is incorrect. 120 cfm = tiny turbo. You should contact your turbochargers' manufacturer and find out what it really flows, and multiply that by 2.

Some don't take much stock in DD2000, one guy even told me it's "Nintendo"-stuff. I don't think so. You have to be able to estimate somehow, and be able to somewhat accurately compare cam grinds, etc.
I have always thought it was a little bit optimistic, myself, but it's worth mentioning that Hot Rod magazine compared DD2000 to an actual dyno pull and the numbers tracked remarkably closely.
I have always thought DD's turbo program was a little whacked. They don't have anything for number of turbos, sizes of downpipes, etc., things that I think are kind of important. So my guess would be to double the cfm of the turbo to get some idea of peak power. The problem with that of course is that then DD2000 is going to probably increase turbo lag too, so I wouldn't put too much stock in anything but the peak power and torque, because you know turbo lag will vary using two smaller turbos rather than one huge one.

By the way, your name came up in the C3 forum under a thread, "Who has the strongest C3". I asked you a question on there, what does it feel like to hit the gas at 120 mph and actually go sideways.
We're politely awaiting your answer.

 

Intercooler efficiency only 40%???

Marck

 

Like I mentioned above, I agree, the Turbo portion of DD2000 is weak. The range of input is .1 to 1000 cfm. Each one of my turbo's flow 900 cfm, so I can't even input 1800cfm. Also, say you put 999cfm, the engine actually makes LESS hp than if you put 100 cfm... That's why I was thinking that the number they really want is the flow Rate in lbs/min, which is about 120-130, each is rated for around 60-65 lbs/min. I don't know for sure, and the User's Manual is no help.

I'm a believer in the potential of DD2000. If you model your engine correctly, at least naturally aspiraed, it is amazingly accurate.
Here's a comparison of how my NA SBC 427 fared on a Superflow 600 engine dyno vs. what DD2000 predicted for it. Amazingly accurate.



I haven't driven my car yet with the new TT setup, another 6 weeks or so, we don't dyno until June 8, and if I'm satisfied with the results, then I'll put the motor in the car, which will only take me a day or two. I don't really like to get into those types of discussions, being the "king of hp hill" or whatever is not of interest to me. There are too many great cars on this forum to rank one over another. But when I drive it, I'll let you know. I will say that when I drove it with the 650hp SBc 427, it was a real handful, but it put a huge grin on your face, as well as a big lump in your throat. Too much throttle in a turn and it would easily come out from under you.

Twinnie, 25-40% Efficiency is typical of a air/air intercooler. Water/air can get up into the 70-80%, and ice water can get you close to 100% or more.





[Modified by Monty, 7:53 PM 5/16/2002]

 

Monty, I wonder if DD2000 wants the island cfm - cfm at peak efficiency not max cfm. That's what engine analyzer pro wants. I'll run your combination on engine analyzer pro if you're interested - it has a lot more detail on turbochargers.

BTW where did you get your TIG welder and what was the price? I know the list price but wonder what the street price is.

Edit: I ran your combination. Engine analyzer pro predicts:

14.7 PSI
892 ft-lb @ 4800 rpm
1058 hp @ 7200 rpm

20 PSI
1029 ft-lb @ 5000 rpm
1190 hp @ 7600 rpm

All on race gas or else severe detonation - I can back the timing off - running 20 degrees max for these runs.

I had to make assumptions - intake runner length 3.5", headers 2" o.d. & 14" long, & ceramic coating on pistons and combustion chambers. I used a compressor map from this web site for the 60-1
http://www.turbocharged.com/catalog/compmaps/fig9.html

Otherwise I think I have everything from your web site.

The torque curve goes up a cliff from 2500-3000 rpm and is fairly flat from that point on with the above mentioned peaks. I hope this is more accurate than DD2000 as it seems in line with your goals. let me know if you want me to make any changes and re-run or post a graph.



[Modified by torquejunky, 7:20 PM 5/16/2002]

 

Torquejunky,

Thanks for taking the time to run it throught EAP. I used the compressor map for the 60-1 from Turbonetics' catalog, you may be onto something regarding the Island flow, not peak flow. The DD2000 User's Guide doesn't say though.

My headers are 1 7/8" diameter. The primaries average around 18", and the intake runners on my manifold are 5". My heads are at Fast Times, but I'd guess their runners are about 3.5". Those rpm points are higher than I had hoped, I was hoping for peak TQ at around 4500rpm, and peak HP at around 6500-6800rpm. I also ordered a 248/248, .653"/.614", 115 LSA, 111 ICA mech roller cam. We're going to try it, as well as the 256/256, .660"/.621", 115LSA, 111 ICA mech roller cam

I bought my TIG welder from a local BOC Gases store. I paid $1350 for the Lincoln Squarewave 175 Pro, which I've found seems to be a good price. There is a local welding supply store that was advertising it for that price on their website, but they didn't have t in stock. The BOC store was nearby, so I stopped in and they met the price. They didn't really even question the price, even though they had a sale price of $1600 on it. I guess it goes to show what the markup is on this stuff, either that or due to the slower economy, especially in manufacturing, they were willing to deal. It seems to be a good all around welder, especially for the home shop/garage and can weld up to about 3/8" steel/stainless, and about 1/4" aluminum.

 

Not much work here - I'm always playing around with EAP and already had your basic engine in my library. Thanks for the info on the TIG welder.

I ran EAP again with the correct exhaust and intake + the smaller cam. It now predicts:

14.7 psi
916 ft-lbs @ 4000 rpm
1047 hp @ 6800 rpm

20 psi
1057 ft-lbs @ 4400 rpm
1185 hp @ 6800 rpm

The HP is pretty flat from 6000 rpm to 7600 rpm for both boost levels. I'm calculating in 400 rpm increments so the peak may be a little higher or lower.

One parameter in EAP that has a pretty big effect on turbocharger performance is the turbine nozzle diameter - minimum area in the nozzle section as the exhaust first enters the turbine. Basically if it's to large the boost won't build until high rpm, to small & the boost is almost instantaneous but it becomes a restriction at high rpm. I let EAP size it. If you can measure yours I'll re-run EAP. Playing with it I can see it is critical - the rpm at which peak torque & hp occur changes drastically with its size (as well as peak HP quantity).

 

What pricing have you found on the Squarewave 175 Pro?

I like your number better. Doug Hegge has been helping me run numbers through EAP as well, I think it handles turbos much better than DD2000. I could live with 900+ ft lbs and around 1050hp, especially at those rpm points. Now the question is will it make it on pump gas? The HKS wastegates have 20# springs in them, but I don't know if I can make that much boost on 93 octane.

The turbine inlet tapers from 2.5" to about 1.75". It tapers from round to oval so it's kinda hard to say what the minimum dimensions are, I'd guess 1.75" x 1.25" or so.

Precision told me the PT-52's with their .85 turbine hosuing should spool up by 3000 rpm on my 427. That's one thing DD2000 doesn't even ahve an input for, turbine A/R, which makes a huge difference in terms of when the trubo spools up and makes boost.

 

I'm ordering EAP tomorrow. Doug was kind enough to run my setup through EAP and her's what it predicted. This chart shows both his TT SBC 375 (CURRENT) and my TT SBC 427 (LAST). Turbos are pretty cool! Now the only question is OCTANE......







[Modified by Monty, 12:13 AM 5/17/2002]

 

Monty - You had better hope those torque numbers are wrong or you are in worse trouble than I am!! I think torquejunky's numbers looked a little closer. The torque curve seems to shoot up to soon & then drop off too soon on the one you ran. Either way, it's fun to guesstimate. You're gonna be making more power than you can ever use. Maybe like Momo said, we should have a contest to see who can get sideways the quickest! Can someone run one of those software tests for me? I've never had one run & I'm curious. What numbers do I need to provide?

 

Steve,


Bore, stroke, head flow in cfm(intake and exhaust) at various lift points, valve diameters, compression ratio, cam specs (lift, duration, LSA, ICA), spca on your superchargers and intercooler, intake cfm, etc....

I'm betting your jaw will drop when we run your setup through it. Do you really have any idea of how much power your caris going to make??? I've got a feeling you're gonna scare the crap out of yourself the first time you drive that thing. Me too!!! I've got no clue either....I figure it can't be any worse than leaning on your knee at 120mpg on a motorcycle...

Next year, we've all got to meet up at the Forum Cruis-in and drink many beers! Hopefully someone will be smart enough to take our keys from us ahead of time!

 

I haven't really researched the pricing on the 175 Pro yet. I just know the list is $1,743 so you did really well. $1,350 sounds a whole lot better to me.

I think you're going to like EAP Monty. The only thing I don't like is the hardware key you have to install on the parallel port

Based on a 1.75x1.25 oval dimension (smaller than I had been using) the turbo comes on sooner but HP is down a little. I think the original was likely more accurate as this is predicting high boost at 2400 rpm vs. the original that didn't get to high boost until 3000 rpm like Doug's. Here's the latest graph at 20 psi & 14.7 psi:



Merlin I didn't realize you're so close. I'm about 10 minutes from Issaquah. It would be :cool: to see your car sometime. I'll run EAP for you if you supply specs but I can't get to it until the weekend.


[Modified by torquejunky, 2:00 AM 5/17/2002]

 

 

Torquejunky,

I was told by Precision that the PT-52's should really start making significant boost at about 3000 rpms on my 427, so it sounds about right.





[Modified by Monty, 9:14 AM 5/17/2002]

 

Monty,
Have you ever run a sim on Turbo Calc? Here is a sim of my motor for example. I just used (Half) 4 cylinders to simulate twin turbos and mult X2 for the final number when your done. It also maps the compressor curve for you.
Frank

 

Frank,

I've never heard of that application, where do you get it. Is it basically like DD2000, but for turbo engines?

 

Monty,

Just visit, http://www.turbofast.com.au/software.html I've received some very good info from them about my application. I used the DD2000 to simulate my combo (normally asperated) to calculate the Volumetric Efficiency / RPM points and input the data in TurboCalc. Like all desktop software it has limitations but it's very close for a ball-park. I also like the EFI fuel portion of the software. I did some number crunching for a buddy of mine before we dyno'd his combo and TurboCalc was only off by 14HP! You can also use it to compare different compressor trims for maximum efficiency through the peak torque curve...

Frank


[Modified by Stingraycrazy, 6:49 PM 5/18/2002]