Why run twins if new singles are so good?
06-07-2007, 01:19 PM
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Why run twins if new singles are so good?
Trying to figure out if I am better off running twins or just a good single(like a SPS62) for a truck I am about to build. I keep hearing mixed stories and don't want to regret anything. Looking to use a Smarty, pressure box and maybe injectors to be in the 550-600hp range. Obviously all the tranny and fuel mods will be done, but I can't get a straight answer on the turbo(s). The truck will be used as a daily driver and I will tow on the weekends at elevation(5000-7000ft) during the winter, but only like 2000lbs. If money was not an option, what are the pros/cons of each? Thanks.
06-07-2007, 01:23 PM
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Trying to figure out if I am better off running twins or just a good single(like a SPS62) for a truck I am about to build. I keep hearing mixed stories and don't want to regret anything. Looking to use a Smarty, pressure box and maybe injectors to be in the 550-600hp range. Obviously all the tranny and fuel mods will be done, but I can't get a straight answer on the turbo(s). The truck will be used as a daily driver and I will tow on the weekends at elevation(5000-7000ft) during the winter, but only like 2000lbs. If money was not an option, what are the pros/cons of each? Thanks.
i personally run a sps66 from II and couldent be happier
06-07-2007, 01:47 PM
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Firstly, You won't be able to tow at 600hp with a 62.....with twins you will. The volume of air is what is important. With a 62 you can make big dyno numbers and run good times on the strip but you won't be able to tow at high power without the EGT's hitting the aluminum melty stage. Add a big bottom turbo to that same 62 and you get a least double the volume of air and you can tow at 1200egts and be making more power. All of the great singles are limited by the total volume of air you can push. Take a K-31 hybrid/Aurora 5000.... run it as a single ....make 700 hp...run a s500 below it and make 1200hp.... Take a k31 put it on the bottom of a twins below a good 62 make 775hp. The singles are great for hot rodding, sledpulling, and towing occasionaly. The twins are good for everything and generally will do all of the above a little cooler at lower drive pressures which will make you engine last longer. The downside of pushing a single to its max is that you run drive pressure way up and EGT's way up and you get engine damage guaranteed. There are people on here think that running EGT's over 1350 everyday is cool....it is till the pistons melt and the exhaust valve seats drop the valve guides and seals self destruct and you get that little tick in your engine. Of course running a set of twins to 90psi every day can have the same effect....lesson learned
Everything has its limits.ks
Everything has its limits.ks
06-07-2007, 02:28 PM
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Firstly, You won't be able to tow at 600hp with a 62.....with twins you will. The volume of air is what is important. With a 62 you can make big dyno numbers and run good times on the strip but you won't be able to tow at high power without the EGT's hitting the aluminum melty stage. Add a big bottom turbo to that same 62 and you get a least double the volume of air and you can tow at 1200egts and be making more power. All of the great singles are limited by the total volume of air you can push. Take a K-31 hybrid/Aurora 5000.... run it as a single ....make 700 hp...run a s500 below it and make 1200hp.... Take a k31 put it on the bottom of a twins below a good 62 make 775hp. The singles are great for hot rodding, sledpulling, and towing occasionaly. The twins are good for everything and generally will do all of the above a little cooler at lower drive pressures which will make you engine last longer. The downside of pushing a single to its max is that you run drive pressure way up and EGT's way up and you get engine damage guaranteed. There are people on here think that running EGT's over 1350 everyday is cool....it is till the pistons melt and the exhaust valve seats drop the valve guides and seals self destruct and you get that little tick in your engine. Of course running a set of twins to 90psi every day can have the same effect....lesson learned Everything has its limits.ks
Everything has its limits.ksLOL, Good answer!!
06-07-2007, 03:42 PM
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Excellent writeup
Firstly, You won't be able to tow at 600hp with a 62.....with twins you will. The volume of air is what is important. With a 62 you can make big dyno numbers and run good times on the strip but you won't be able to tow at high power without the EGT's hitting the aluminum melty stage. Add a big bottom turbo to that same 62 and you get a least double the volume of air and you can tow at 1200egts and be making more power. All of the great singles are limited by the total volume of air you can push. Take a K-31 hybrid/Aurora 5000.... run it as a single ....make 700 hp...run a s500 below it and make 1200hp.... Take a k31 put it on the bottom of a twins below a good 62 make 775hp. The singles are great for hot rodding, sledpulling, and towing occasionaly. The twins are good for everything and generally will do all of the above a little cooler at lower drive pressures which will make you engine last longer. The downside of pushing a single to its max is that you run drive pressure way up and EGT's way up and you get engine damage guaranteed. There are people on here think that running EGT's over 1350 everyday is cool....it is till the pistons melt and the exhaust valve seats drop the valve guides and seals self destruct and you get that little tick in your engine. Of course running a set of twins to 90psi every day can have the same effect....lesson learned Everything has its limits.ks
Everything has its limits.ksNow let's look at how this hot rodder was equipped. He has a long bed dully. He's a contractor and it said on the side of the truck he does bobcat work,... getting a clue? He is running a brand new A5k (the big single),... nothing wrong with the A5k, it's just how it was being used here. He had a TST and CLDL stacked (enough timing???) Can you imagine the heat built trying to get something close to 10k load moving and that's if he has no other equipment on his truck or the construction trailer complete with bobcat, and then if he failed to turn down both the TST and CLDL to towing levels. It was total junk when he got done with it. And believe it or not,... he drove it into the shop????!!!!! Wow. There will be a totally new complete motor in his future and he has NO warranty.
I'm with ABC and will run my twins. Sweet.
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06-07-2007, 03:43 PM
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Firstly, You won't be able to tow at 600hp with a 62.....with twins you will. The volume of air is what is important. With a 62 you can make big dyno numbers and run good times on the strip but you won't be able to tow at high power without the EGT's hitting the aluminum melty stage. Add a big bottom turbo to that same 62 and you get a least double the volume of air and you can tow at 1200egts and be making more power. All of the great singles are limited by the total volume of air you can push. Take a K-31 hybrid/Aurora 5000.... run it as a single ....make 700 hp...run a s500 below it and make 1200hp.... Take a k31 put it on the bottom of a twins below a good 62 make 775hp. The singles are great for hot rodding, sledpulling, and towing occasionaly. The twins are good for everything and generally will do all of the above a little cooler at lower drive pressures which will make you engine last longer. The downside of pushing a single to its max is that you run drive pressure way up and EGT's way up and you get engine damage guaranteed. There are people on here think that running EGT's over 1350 everyday is cool....it is till the pistons melt and the exhaust valve seats drop the valve guides and seals self destruct and you get that little tick in your engine. Of course running a set of twins to 90psi every day can have the same effect....lesson learned Everything has its limits.ks
Everything has its limits.ksNot true I have a 66 with ton of fuel and pull every weekend either my mules (15k-18k) my boat, or a 45ft flatbed with two race trucks from Salt Lake to Seattle. On that trip I never hit 1400 degrees and went through several steep long mountain climbs. Yes I want twins but the singles can perform. On the other hand my buddy truck has close to the same setup and can't keep from hitting 1600 degrees??????
06-07-2007, 03:50 PM
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But,....
Not true I have a 66 with ton of fuel and pull every weekend either my mules (15k-18k) my boat, or a 45ft flatbed with two race trucks from Salt Lake to Seattle. On that trip I never hit 1400 degrees and went through several steep long mountain climbs. Yes I want twins but the singles can perform. On the other hand my buddy truck has close to the same setup and can't keep from hitting 1600 degrees??????
06-07-2007, 03:50 PM
#11
I hit 1400 yesterday with a smarty on 6 and tst on 3/0 empty. I kinda wonder if my turbo cools as good as it is supposed to. I have 2 pyros and they are fairly close so I doubt it is the guage(s)
06-07-2007, 03:55 PM
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Well my truck has never hit 1600 and I have pulled on crazy larry and it completly powder coated my trailer and I did hit 1450. On that trip to Seattle I had the chip set on tow my truck never stoped smoking and I pulled up a couple 8% grades going 85mph at 2600 rpm's in 6th gear. I will agree with you, you can do more with twins and do it better.
06-08-2007, 12:51 AM
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I really wish I could get my twins to work right. A stock 7.3 beat me BAD off the line tonight....but after I got spooled, it was like he was standing still. We raced from 50...he got a half lenth ahead of me before I got spooled, then it was over. From 60 i flat left him in smoke. I waved him over and we talked a bit. I was disappointed to see his wife and kids with him 
Anyhow...I've been doing a little towing even though my twins aren't working correctly. I tow with the same settings I run on the street.... easily 550+hp (judging off of how my SPS 62 ran with its dyno # of 579hp). I only have to watch EGT's if I'm lugging it. Down gear to 3rd to pull a long hill to get boost up and EGT's stay at 1200* while accelerating from 65 to 80...lug it and EGT's can hit 1400*. Passing cars with twins vs a big single while towing is totally night and day.
what totally baffles me is towing or not, EGTs are only about 300* difference. Granted, i tow light (4k) but still...
I've contacted Jim Fulmer about helping diagnosing my twin issues...such a nice guy. I'll be on the phone with him this weekend concerning my issues.
Even though my twins arent working correctly, they are still worth it to me and when I do get them working right...I'll be the happiest DTR member ever
Anyhow...I've been doing a little towing even though my twins aren't working correctly. I tow with the same settings I run on the street.... easily 550+hp (judging off of how my SPS 62 ran with its dyno # of 579hp). I only have to watch EGT's if I'm lugging it. Down gear to 3rd to pull a long hill to get boost up and EGT's stay at 1200* while accelerating from 65 to 80...lug it and EGT's can hit 1400*. Passing cars with twins vs a big single while towing is totally night and day.
what totally baffles me is towing or not, EGTs are only about 300* difference. Granted, i tow light (4k) but still...
I've contacted Jim Fulmer about helping diagnosing my twin issues...such a nice guy. I'll be on the phone with him this weekend concerning my issues.
Even though my twins arent working correctly, they are still worth it to me
and when I do get them working right...I'll be the happiest DTR member ever
06-08-2007, 12:54 AM
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ATS, II, Piers, Artic air twins? I have heard good and bad about all of them. Give all of them a call and see who wants your buisness and is most willing to help you decide.
Only one I personally would steer away from is shied and thats just cause I felt there plumbing that I saw on there dispay unit was very poor. Grind and hack marks, choppy paint, and cut into the radius with heavy schedule carbon pipe fittings,yikes. No offense to their fans but if its your display ya know make it look GOOD. I also hear that Artic Air is the cheapest way to do twins but that has been debated before. My .02
Only one I personally would steer away from is shied and thats just cause I felt there plumbing that I saw on there dispay unit was very poor. Grind and hack marks, choppy paint, and cut into the radius with heavy schedule carbon pipe fittings,yikes. No offense to their fans but if its your display ya know make it look GOOD. I also hear that Artic Air is the cheapest way to do twins but that has been debated before. My .02