Background: 363 Ford CSU carb'd engine, Vic Jr intake, mild hyd roller cam at .540, 560, with a 110lsa. MSD btm box [I just couldn't get the MSD 6al2 programmable to work]

Two T4 turbos [I can't remember the specs they were on my old hard drive that got toasted] I do remember it was something like a T trim impeller 55mm, with a stage 3 turbine. I can look at the housings tomorrow if necessary for the housing sizes.


At the present time I have two 3" pipes going from the header collector to the turbos in the front of the bed of the truck with an H pipe in the middle [small truck like an old Ranger, or s10]. Then 3 inch pipes to the end of the bed.

As of now the boost starts to come on about 6500 rpms which is waaaay to high for street [for which this truck is driven].

Would a two inch be about right to get the turbo spool up a bit quicker, like say around 3k?

I do know from reading here that the turbines are too big for a remote setup, but I just want to start driving the truck so different turbines will have to wait.

 

smaller tubing should help and maybe try heat wrap too,, maybe consider blocking half of the turbine inlet if that might be an option

 

What heads on the 363? If they are stg 3 turbines that would make them t3's which should be workable with a good running 363. If they are t4's they're most likely p trims which are larger, but possibly workable. Post some pics of the turbine housings, and a/r numbers. A drop from 3" to 2" is the place to start. Also check for leaks on the hot, and cold side.

 

Ok thanks guys. I will give it a try, and save this thread for update.

Oh, and the heads are AFR185's with the big chambers [too lazy to look it up right now].

 

Something sounds off. 3" is a poor choice for that setup, but 6500 rpm is ridiculous. Even with 3" pipe it should spool sooner. I'd be building a boost leak test rig and double checking WG's are staying closed. I really think something else is off.

2" 16g tubing is plenty for around 900 crank. I run it on a 370, and I'm hitting some sort of wall around 1000 crank. Not sure if it's the piping or what. But if your goals are below 900 crank I'd go 2". If above shoot for 2.25".

Gotta remember though 2" exhaust tubing is only 1.86" ID or so. I'd go with 2.25 16g tubing if you want 900 or more.

#ad

 

I'm curious about setups like that. How much heat energy does the system lose, and how much restriction does the long pipe between the engine and the turbo add?

It seems moving the turbo back away from the header can't be very good. Maybe once the exhaust gas gets rolling through the pipe when it is under boost, but I don't understand why taking initial heat out and having to pressurize all that pipe length couldn't slow spool down.

 

I dont know what a stage 3 turbine is. That could be different for various manufacturers. Which could hugely affect spool up in a rear mount setup.

Honestly though, 6500!! What is your timing out of boost.
Sounds like its more in the over all tune though.

 

Closer to the manifold the better. There is a difference between slowing spool times say 500-1000rpm which is normal with a remote mount, to not making boost till 6500rpm. If the turbo wheels are really 50-55ish MM they are small units and something else is off. I'd guess WG's arent' working correctly or there is a large leak.

 

I'm going to say its the wastegate tubes. I used the hard plastic lines like the air lines found the big trucks.

Problem is that if you don't cut the ends fairly straight they won't seal, and let air escape.

The reason I know is that I also have these lines on the Shockwave shocks.

I think I will go back and just use rubber vacuum lines. Not as high tech looking as the hard plastic, but I won't have to worry about leaks.

 

I will say this.

If you're not building a vehicle for all out racing [like my truck], and just building a street machines, remote turbos are a good way to go IMO.

For one its easier to work on the turbos, as you have more room [trunk, or truck bed].

The exhaust plumbing is easier to fab.

The engine compartment stays cooler.

I would also say that you have less back pressure as in running full length headers without major turns etc [just a theory here, not a fact].

Less weight over the nose of the car to better balance the F/R weight bias.

The draw backs as I see them is:

You will have to run some type of return pump setup, which equals extra plumbing, and cost.

Slower spool up times. Of course that, like most things can be tuned.

Thanks for all of the help, the truck is running great since I got the turbine seals to seat. I wish I had the specs on the turbo, but like I said they are on an old hard drive that I took out of a dead computer.