Hp range for Towing Twins

D

dieselduck

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I have a 06 CR auto, and was wandering what range the typical "towing twins" have at the bottom? I was looking at the set from Source Automotive, they say 650hp at the top of the range (most towing twins are rated about the same at the top HP). My question is how low or a street tune if you will, will twins like these operate reasonably eficiantly? 400hp maybe? How big an injector and CP3 would I need to run a 400hp street tune and 600+ at the track? would an aftermarket intercooler be nessasary? I plan on diching the Banks and switching to a Smarty in the future, as well as a fully built Trans. Any suggestions are welcome.:thankyou2:
 
your stock turbo over a ht3b or s400 would work for what you are looking for. 400hp might be a little low for a street tune because the primary will hardly be lit. You can cool an easy 500hp on the street and tow with it but crank it up for 600+ at the strip. Just because you have the ability to cut loose 500hp does not mean you have to use it on the street but it will be there if you put it to the floor. cp3 and injector advice is not my forte, I'm running a 12v.
 
Is their some kind of formula for efficancy? Say 80% of twins max hp rating or something? How do you know that it takes 500hp to keep the primary "lit" as you say? I assume the max cfm of the setup factors in somehow, can you show me a formula?
 
I ran Rip's twins on my 02 and they did great towing with about 450hp and even ran great with the truck running stock injectors and no chip. I would see about 19psi and never get over 1000* EGT's. The twins were slower to spool than a stock turbo, but they still work and you can light the primary, but not very much.
 
I have Source Automotive twins on both of my trucks. The twins on my 05 are hardly what you would call a towing set (66/16SS over a S480), but the ones on my 02 do work for towing. The 02 has a 62/65/14 over a S400, and it makes 648hp, 1283tq. EGT's at the end of the 1/4 mile are around 1350 on hot days.

When we take both trucks to the track, the 02 tows the 05 on a flat bed trailer. Combined weight of the 05 and trailer is right at 9500 lbs. With the electronics off on the 02 it is still able to make about 500hp, but that is more hp then is usuable when towing. You just have to control the power output with the right foot. It is not an EGT problem. It's more a traction problem. The cooling system will actually overheat before the EGT's get to high.

At 15psi of of total boost the 02 is making 3psi out of the primary. This is pretty close to what it runs when pulling the trailer/truck at 65mph on flat ground. If I keep the rpms above 1700, EGT's are never a problem.

The twins on the 02 have been on there for about 108,000 miles, and have not been off since I put them on. If I remember correctly I've made about 1100 1/4 mile passes since I put the twins on. The truck has over 1800 1/4 mile passes total.

Combining the right size turbos, with the right size injectors, is key. Give Rip or Bill a call at Source Automotive, and they will get you setup with a good combo.

Oh, and I have towed the 02 on the trailer with the 05. It works, just have to keep the rpm up, and plan on washing a little smoke off. :hehe:

Paul
 
thats the same set up i am doin, but with a 13ss housing. at 650 hp do you think the smaller passages in the cast housing are starting to be an issue? whats ur max boost vs drive?

thanks don

ps - is your 02 a dually?
 
PaulB: your running 500hp with no electronics. You must be running good sized injectors. How's the smoke on the 02? I have always thought that making HP mechanicly rather than electronicly was the key to longevity, it sounds like you have proven that. Their are pages upon pages in another forum about burnt pistons in late model cr running twins and high HP. Honestly this scares me to burn up my motor runnig twins. I think those other guys stacking tuners and pressure boxes is simply too much.:thankyou2:
 
paulb said:
I have Source Automotive twins on both of my trucks. The twins on my 05 are hardly what you would call a towing set (66/16SS over a S480), but the ones on my 02 do work for towing. The 02 has a 62/65/14 over a S400, and it makes 648hp, 1283tq. EGT's at the end of the 1/4 mile are around 1350 on hot days.

When we take both trucks to the track, the 02 tows the 05 on a flat bed trailer. Combined weight of the 05 and trailer is right at 9500 lbs. With the electronics off on the 02 it is still able to make about 500hp, but that is more hp then is usuable when towing. You just have to control the power output with the right foot. It is not an EGT problem. It's more a traction problem. The cooling system will actually overheat before the EGT's get to high.

At 15psi of of total boost the 02 is making 3psi out of the primary. This is pretty close to what it runs when pulling the trailer/truck at 65mph on flat ground. If I keep the rpms above 1700, EGT's are never a problem.

The twins on the 02 have been on there for about 108,000 miles, and have not been off since I put them on. If I remember correctly I've made about 1100 1/4 mile passes since I put the twins on. The truck has over 1800 1/4 mile passes total.

Combining the right size turbos, with the right size injectors, is key. Give Rip or Bill a call at Source Automotive, and they will get you setup with a good combo.

Oh, and I have towed the 02 on the trailer with the 05. It works, just have to keep the rpm up, and plan on washing a little smoke off. :hehe:

Paul
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Great answer Paul. I too have Rips Twins and I tow my Toy Hauler 12,000+ lbs. i am running Smokem's 5 x .014 injectors and things do get hot, but like Paul said control with your right is a must. when pulling long steep grades
 
Our other '05 has twins like Paul's 2nd Gen - except with a 13SS housing.

The motor has every airflow mod possible (and then some:Cheer:) and drives pretty well with the F5.1 sticks - 17mpg hwy, which is pretty good for only clearing the smoke halfway and still pumping out 738HP.

As said above, the limiting factor is the cooling system more than the EGT... you can hot-lap it all day, but E.T. falls off with the 3rd pass.

More than anything else, drivability hinges on operating RPM and the skinny pedal.
 
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