Dyno Results - Twin Turbo SBC 427
06-25-2002, 03:13 PM
#1
Le Mans Master
Thread Starter
Dyno Results - Twin Turbo SBC 427
We made our first dyno pull today during my lunch hour. I snuck out a little early and finished installing the oil pump and oil pan. I'm sure I looked kinda funny to some some of Jeff's customers working in the dyno room in chinos and a polo.
Anyway, the oil pressure issue is resolved and we made one pull just to verify that everything was cool. This is with the initial tune, overly safe - a rich A/F ratio and minimal timing, and we only took it to 6000 rpm, I'll set the rev limiter at 7000 again, but we'll probably take it up to 7500 later today when I go back and we start tuning it.
This is all on pump gas, no tuning, with less than 10 psi of boost:
RPM........TQ.........HP
4100......757.9.....591.7
4200......759.7.....607.5
4300......757.1.....619.9
4400......755.6.....633.0
4500......757.9.....649.4
4600......773.2.....677.2
4700......789.4.....706.4
4800......801.5.....732.5
4900......822.5.....767.4
5000......843.5.....803.0
5100......859.3.....834.4
5200......871.4.....862.8
5300......873.5.....881.5
5400......878.0.....902.7
5500......888.5.....930.5
5600......905.5.....965.5
5700......904.0.....981.1
5800......910.0.....1005.0
5900......917.4.....1030.6
6000......922.3.....1053.7
As you can see, torque was still climbing at 6000 rpm when we stopped the dyno run, and horsepower was still climbing almost 30hp every 100 rpm, so there's still alot left in it, just the way it's tuned if we ran it up to 7000rpm or more. We're going to lean out some of the fuel map and add a couple degrees of timing. The way it looks, I could probably get somewhere around 1000-1050 ft lbs, and around 1300hp with tuning and a little more boost, and taking it all the way up to 7000 rpm or so - maybe more.
I'm going back to Fast Times today at 3:30 and we'll start tuning and turning up the boost controller. Right now boost is set at it's minimum setting, which is 9.8 psi
Anyway, the oil pressure issue is resolved and we made one pull just to verify that everything was cool. This is with the initial tune, overly safe - a rich A/F ratio and minimal timing, and we only took it to 6000 rpm, I'll set the rev limiter at 7000 again, but we'll probably take it up to 7500 later today when I go back and we start tuning it.
This is all on pump gas, no tuning, with less than 10 psi of boost:
RPM........TQ.........HP
4100......757.9.....591.7
4200......759.7.....607.5
4300......757.1.....619.9
4400......755.6.....633.0
4500......757.9.....649.4
4600......773.2.....677.2
4700......789.4.....706.4
4800......801.5.....732.5
4900......822.5.....767.4
5000......843.5.....803.0
5100......859.3.....834.4
5200......871.4.....862.8
5300......873.5.....881.5
5400......878.0.....902.7
5500......888.5.....930.5
5600......905.5.....965.5
5700......904.0.....981.1
5800......910.0.....1005.0
5900......917.4.....1030.6
6000......922.3.....1053.7
As you can see, torque was still climbing at 6000 rpm when we stopped the dyno run, and horsepower was still climbing almost 30hp every 100 rpm, so there's still alot left in it, just the way it's tuned if we ran it up to 7000rpm or more. We're going to lean out some of the fuel map and add a couple degrees of timing. The way it looks, I could probably get somewhere around 1000-1050 ft lbs, and around 1300hp with tuning and a little more boost, and taking it all the way up to 7000 rpm or so - maybe more.
I'm going back to Fast Times today at 3:30 and we'll start tuning and turning up the boost controller. Right now boost is set at it's minimum setting, which is 9.8 psi
06-25-2002, 03:22 PM
#3
Melting Slicks
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Re: (scorp508)
OMG, thats wicked.... How in the heck could you even leave that thing before pulling her up to 7500! You must have some excellent self control!
Congrats on getting the beast running..... We are hoping for some video so we can hear the engine at full song.
Congrats on getting the beast running..... We are hoping for some video so we can hear the engine at full song.
06-25-2002, 03:35 PM
#4
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Re: Dyno Results - Twin Turbo SBC 427 (Monty)
yeowie..... :eek: :eek: :eek: :eek: :eek: :eek: :eek: :eek: :eek: :eek: :eek:
06-25-2002, 03:37 PM
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Re: Dyno Results - Twin Turbo SBC 427 (Monty)
Congratulations Monty! It's been a tease waiting for your dyno numbers. Sounds like 1300 hp is easily there with a little more rpm & tuning. I'm glad you figured out the oiling problem. The .080" oil restrictors fixed it?
06-25-2002, 03:53 PM
#7
Le Mans Master
Thread Starter
Re: (MikeC)
I'll take some .megs this afternoon when I go back, and scan the dyno sheets later tonight. Believe me, the thought of not going back to work crossed my mind, but I had a conference call I had to be at. Anyway, Jeff was busy trying to get an engine assembled for a customer and I didn't want to inconvenience him. Although I've been doing 90% of the work/troubleshooting on my motor while it was in his shop and on the dyno, he's been very helpful.
All I did was swap out the .200" restrictors for .080", and gave the pressure adjustment on the Titan pump a couple of turns.
[Modified by Monty, 1:55 PM 6/25/2002]
All I did was swap out the .200" restrictors for .080", and gave the pressure adjustment on the Titan pump a couple of turns.
[Modified by Monty, 1:55 PM 6/25/2002]
06-25-2002, 04:21 PM
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Re: Dyno Results - Twin Turbo SBC 427 (Monty)
nice numbers man! :cheers:
did ya change your shorts after that first dyno pull? lol
anyway, how much money do you have invested in this engine?.. just curious to see how much something like that costs so i can sell my soul.
did ya change your shorts after that first dyno pull? lol
anyway, how much money do you have invested in this engine?.. just curious to see how much something like that costs so i can sell my soul.
06-25-2002, 05:01 PM
#10
Le Mans Master
Thread Starter
Re: Dyno Results - Twin Turbo SBC 427 (blue_stingray)
Thanks, I am pretty excited. I've been planning/building it since last November, so today is the culmination of over 7 months worth of effort.
The engine was initially built last summer naturally aspirated, and it made 650hp/580tq on pump gas. I ran it for a month and then decided to turbocharge it. If I were to build it from scratch as it is today, without the intermediate NA phase, it would probably cost about $35k, but it could be done cheaper with different components.
The engine was initially built last summer naturally aspirated, and it made 650hp/580tq on pump gas. I ran it for a month and then decided to turbocharge it. If I were to build it from scratch as it is today, without the intermediate NA phase, it would probably cost about $35k, but it could be done cheaper with different components.
06-25-2002, 05:21 PM
#12
Burning Brakes
Re: Dyno Results - Twin Turbo SBC 427 (Monty)
Congratulations on your astounding numbers! How hard do you plan to push it on pump gas? Any plans to *really* push it on race gas???
Also glad to see the oiling issues were not serious.
What tires are you running again? :)
Take care,
Mark
Also glad to see the oiling issues were not serious.
What tires are you running again? :)
Take care,
Mark
06-25-2002, 05:24 PM
#13
Melting Slicks
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Re: Dyno Results - Twin Turbo SBC 427 (Monty)
excellent Monty! Glad to hear the oil pressure problem was a relatively minor fix and you didn't have to rip it apart. I can't wait to see the post-tuning numbers!
06-25-2002, 07:01 PM
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Re: Dyno Results - Twin Turbo SBC 427 (Coupe89)
:cool: The curve to 7500 should be pretty interesting. How early did the boost come all the way in ? Those numbers are mental on 10 psi.
06-25-2002, 07:28 PM
#16
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Re: Dyno Results - Twin Turbo SBC 427 (SloRvette)
Way to go!!! Congratulations!!
Man, boost is a wonderful thing isn't it?
Can't wait to see it all in the car and some track times. That is going to be insane!
I'm sure there were some times you were wondering if it was all worthwhile, but today removed all doubt! There's nothing like a dyno test to start the heart pumping!
Congrats again!
Jim
Man, boost is a wonderful thing isn't it?
Can't wait to see it all in the car and some track times. That is going to be insane!
I'm sure there were some times you were wondering if it was all worthwhile, but today removed all doubt! There's nothing like a dyno test to start the heart pumping!
Congrats again!
Jim
06-25-2002, 09:24 PM
#18
Re: Dyno Results - Twin Turbo SBC 427 (tntcorvette)
Monty, I have been thinking, any reason why you guys did not start the dyno curve in the lower rpm range? I am currious to how it is down low?
Also, is ther eany way to graph out the boost curve related to RPM's on the dyno pulls?
[Modified by bill mcdonald, 5:25 PM 6/25/2002]
Also, is ther eany way to graph out the boost curve related to RPM's on the dyno pulls?
[Modified by bill mcdonald, 5:25 PM 6/25/2002]
06-25-2002, 11:05 PM
#19
Le Mans Master
Thread Starter
Re: Dyno Results - Twin Turbo SBC 427 (bill mcdonald)
Thanks for the compliments and congratulations, it really has been a challenging, drawn out project. There were certainly times when I thought it was a waste of time and effort, but now I'm pretty excited.
The neat thing about it is that it really is "mild", the fuel ratio is on the safe side and the timing is conservative. Jeff and Mark at Fast Times said it's got 1400hp in it, but I'm skeptical about that, becuase Precision only rates each of the PT-52's for 600 hp. We still haven't even touched the boost controller. It's on the minimum setting, relying in the spring in the wastegates only. Curiously, the wastegates only have 10 pound springs, and we amxed out a 2 Bar MAP sensor, 15 psi. It's probably making about 17-18 lbs, we guess, with no signs of detonation. Jeff thought the plugs looked awesome, reinforcing his opinion that there's alot more left in the engine, and that it's a very conservative, safe tune.
We only ran it on the dyno 3 more times. I got there at 3:30 and we weren't able to start dynoing it until after 5:00 because Jeff was so busy. I felt guilty keeping him longer because he was at the shop until 10:00pm last night and he had alot of work left to do today before he left.
We only spun it up to 6600 rpm on the last run, and it made 1151hp at 6600rpm, and still climbing more than 10hp/100rpm, and peak torque was 970 at 6000rpm. It's probably a 1200hp motor at 7000 rpm with the current tune, and we weren't even pushing it hard. It only has 23.5 degrees of timing and it's still on the rich, safe side. I could probably get 1300 hp if we pushed it, added some more timing and leaned it out, but since it's a street car I want it to be reliable on pump gas in any weather. Needless to say, I think turbos are friggin' COOL! My intake air temp was only 126F with nothing more than a little fan going over the intercooler.
We tried to start the dyno run at a lower rpm but the dyno wouldn't hold it, the engine makes too much torque at low rpms for the dyno's "brake" to hold it. I think that's kinda cool too!
RPM....TQ......HP
4100...771.1...602.0
4200...768.5...614.6
4300...770.8...631.1
4400...777.7...651.5
4500...778.9...667.4
4600...788.4...690.5
4700...803.2...718.8
4800...821.7...751.0
4900...850.0...793.0
5000...874.8...832.8
5100...883.3...857.7
5200...901.7...892.8
5300...903.5...911.8
5400...927.2...953.3
5500...926.4...970.1
5600...945.3...1007.9
5700...946.6...1027.3
5800...960.4...1060.6
5900...963.2...1082.0
6000...970.2...1108.4
6100...964.2...1119.9
6200...956.0...1128.6
6300...952.6...1142.7
6400...937.2...1142.1
6500...922.7...1142.0
6600...916.1...1151.2
We just dyno'd with 93 octane pump gas, I was tempted to ask Jeff to fill the tank with some race gas but it was getting late and I could tell he was tired and had more work left to do before he went home. I plan to keep it traction limited by sticking with street tires, something like Michelin Pilots. Hopefully, that will allow me to maintain the IRS, albiet upgraded with better parts.
I wish we could have gotten the dyno runs down to 3000 rpm or so, that's where Precision said it would start making significant boost, but as I mentioned the dyno wouldn't hold the torque below about 4000.
Bill, I would ahve to put together an EXcel spreadsheet, but that's an interesting idea. That's one reason I was really disappointed that we could get the dyno to grab at lower rpms. I wanted to see the affect in power as the turbo's spool up and the engine goes from vacuum to boost.
[Modified by Monty, 9:25 PM 6/25/2002]
The neat thing about it is that it really is "mild", the fuel ratio is on the safe side and the timing is conservative. Jeff and Mark at Fast Times said it's got 1400hp in it, but I'm skeptical about that, becuase Precision only rates each of the PT-52's for 600 hp. We still haven't even touched the boost controller. It's on the minimum setting, relying in the spring in the wastegates only. Curiously, the wastegates only have 10 pound springs, and we amxed out a 2 Bar MAP sensor, 15 psi. It's probably making about 17-18 lbs, we guess, with no signs of detonation. Jeff thought the plugs looked awesome, reinforcing his opinion that there's alot more left in the engine, and that it's a very conservative, safe tune.
We only ran it on the dyno 3 more times. I got there at 3:30 and we weren't able to start dynoing it until after 5:00 because Jeff was so busy. I felt guilty keeping him longer because he was at the shop until 10:00pm last night and he had alot of work left to do today before he left.
We only spun it up to 6600 rpm on the last run, and it made 1151hp at 6600rpm, and still climbing more than 10hp/100rpm, and peak torque was 970 at 6000rpm. It's probably a 1200hp motor at 7000 rpm with the current tune, and we weren't even pushing it hard. It only has 23.5 degrees of timing and it's still on the rich, safe side. I could probably get 1300 hp if we pushed it, added some more timing and leaned it out, but since it's a street car I want it to be reliable on pump gas in any weather. Needless to say, I think turbos are friggin' COOL! My intake air temp was only 126F with nothing more than a little fan going over the intercooler.
We tried to start the dyno run at a lower rpm but the dyno wouldn't hold it, the engine makes too much torque at low rpms for the dyno's "brake" to hold it. I think that's kinda cool too!
RPM....TQ......HP
4100...771.1...602.0
4200...768.5...614.6
4300...770.8...631.1
4400...777.7...651.5
4500...778.9...667.4
4600...788.4...690.5
4700...803.2...718.8
4800...821.7...751.0
4900...850.0...793.0
5000...874.8...832.8
5100...883.3...857.7
5200...901.7...892.8
5300...903.5...911.8
5400...927.2...953.3
5500...926.4...970.1
5600...945.3...1007.9
5700...946.6...1027.3
5800...960.4...1060.6
5900...963.2...1082.0
6000...970.2...1108.4
6100...964.2...1119.9
6200...956.0...1128.6
6300...952.6...1142.7
6400...937.2...1142.1
6500...922.7...1142.0
6600...916.1...1151.2
We just dyno'd with 93 octane pump gas, I was tempted to ask Jeff to fill the tank with some race gas but it was getting late and I could tell he was tired and had more work left to do before he went home. I plan to keep it traction limited by sticking with street tires, something like Michelin Pilots. Hopefully, that will allow me to maintain the IRS, albiet upgraded with better parts.
I wish we could have gotten the dyno runs down to 3000 rpm or so, that's where Precision said it would start making significant boost, but as I mentioned the dyno wouldn't hold the torque below about 4000.
Bill, I would ahve to put together an EXcel spreadsheet, but that's an interesting idea. That's one reason I was really disappointed that we could get the dyno to grab at lower rpms. I wanted to see the affect in power as the turbo's spool up and the engine goes from vacuum to boost.
[Modified by Monty, 9:25 PM 6/25/2002]