Anyone ever try to run sequential turbos?? Does any company make a sequential kit for f-bodies?? Will they make any more power than other TT kits??

Adam

 

There are only a couple of companies making kits for the fbody right now. There are single and twin kits, but no sequential kits. There really isn't a need for a sequential system.

 

he is right...........with a v8, there is absolutely no need to sequential turbos.

not to mention, in a V configuration, a sequential setup would require more exhaust/intake piping than you could ever fit in your car.

 

If you are referring to series plumbing or sequential, there is no need for this in any application under 30# boost. This is needed when 1 turbo cannot efficiently compress the air enough in 1 stage, so it is done is 2 or more stages. Based on their compressor map, many turbos are capable of 30-40# boost, so this is rarely needed in any automotive application.

 

A lot of twin cars run a sequential setup since it gives you boost acrosst the entire rpm range. A supra running out of sequential doesn't make full boost until 4k rpm.

 

Exactly that was my feelings. I saw a dyno graph of a TT setup on a LS1 and it looked like someones heart beat.

 

You can make twin turbos, non sequential, have steady boost throughout the entire rpm range. The turbos I am adding to my 427 small block, will spool fully at 2500, and keep full boost all the way to the moon, or until my bottom end gives.

The reason Supras and smaller engined twin turbo cars use the sequential setup is that since they have less displacement, the turbo's take alot longer to spool up than in a large displacment engine. They have a smaller turbo for the first stage to get the boost started, and the turbos spining. As soon as full spool is on the smaller turbo the larger turbo kicks in and this allows a smoother, and quicker spool up time than a twin turbo, non sequential system would on their engines.

I think that unless you were going to run over maybe 30-35 lbs of boost on a V8, and still wanted to have it keep full boost throughout the entire rpm range, then the sequential setup would be the way to go.

Hunter

 

So what system do you guys recommend for a daily driven, but big power wanted turbo system?? I want it to spool fast and pull throughout the RPM band.

Adam

 

How wide of a torque/boost curve do you want?

My TT SBC 427 starts making boost at 2500rpm and is already making 700 ft lbs by 3000rpm, peaking at almost 1000 ft lbs at 5000 rpm, and doesn't fall below 800 ft lbs until past 7000 rpm. this is on 93 octane. With a 3200rpm converter, you're into boost anytime you want it. I can tell you from first hand experience that it's a pretty good amount of power and torque and is barely manageable with anything near street tires. It pulls hard everywhere, even when it's not under boost the ci's still help it generate good off-idle torque and power.

You do not need sequential twin turbos unless you're planning on running something like 50+ psi of boost, which ain't happening on any engine running anything less than full racing gas, and even then you'd probably start thinking about running alcohol.

Heck, a single T88 starts making boost at a little less than 33,000 shaft rpm, which is not too difficult to achieve at relatively low engine rpm with the right setup. Don't forget that the Supra guys only have half the engine dispalcement of less to motivate their turbos that we do. A single T88 will support up to 1200 hp or so by itself.b

 

I plan on just running a forged 355 so I wont be running the kind of ci's you are. I would like the turbo/turbos to spool by 2500-3000 and have a good amount of power until the 7000 rev limiter. Do you think a single or twin system would be best??

 

A larger single turbo will almost always be more efficient than a pair of smaller twin turbos and on a 5.7L V8, spooling it up won't be a problem. Don't confuse yourself with what you read or hear about regarding the 3 liter, big single turbo Supras.

It seems to be a popular internet myth that two smaller turbos spool up quicker than a single larger turbo, but what people forget is that you are dividing the exhaust energy in half for twins. Consider that even a T88 starts to make boost at a little under 33,000 shaft rpm, while a 60 or 60-1 takes over 46,000 rpm to make boost.

The main advantage of twin's over a single is tupically packaging, especially with a V engine, however, a single turbo system can be desinged and built very efficiently. Another reason TT's are more poular is that they are generally considered more "trick". Obviously I have a TT system and I like it alot, but the facts are the facts. In reality you can easily make more power either way than you can ever hope to use and they will both work very effectively.