Turbocharger manifold advice

[womble]

Hi All,

I'm in the planning stages of a turbocharger conversion of an N/A engine. This is the first time I've tackled one of these as I've only worked on N/A engines before. I need some advice regarding a turbocharger manifold suitable for high performance use.

1. Regarding pipe lengths, is it worth designing them for a tuned length as N/A applications. And what rpm band would be most suitable, eg. low rpms where the turbocharger is in low boost (would this help widen the torque spread) or higher up the rpm range.

2. Equal lengths. Are turbocharged engines particually sensitive to differences in pipe lengths between cylinders. What tolerence in lengths would be acceptable.

Turbochargers currently being considered are garrett GT32 (twin entry, I understand this can use the exhaust pulses better) or T3/T4 hybrid (single entry). Engine is 1998cc 4 cylinder with operating rpm 3000 - 7000rpm. Please ask if you need more info.

Advice from automotive professionals with turbocharging experience would be most welcome!

Regards,

Womble

 

[Retracnic]

Womble,

I'll attempt to address your questions:

1. Helmholtz resonance tuning is not a requirement for a forced induction application. In fact, the varying inlet charge pressure, and the pressure pulses induced by the compressor make such tuning very difficult.

2. For most forced induction applications you will want to keep intake runner length as short as possible. Due to the increased density of the charge, long intake runners can result in poor throttle response and decreased high RPM performance. Where space and packing allow, all runners should be kept to an equal functional length.

Good Luck,
Bryan Carter

 

[patprimmer]

There are several previous threads where this subject is discussed at length. Do a search and save us all the trouble of doing it again, and again and again.

There is discussion there re manifold volumes and response times, and on manifold surface area and heat loss and on the effects of variations in air temperature and density on the tuned length

Regards
pat

 

[womble]

Retracnic,
Thanks for your comments on the intake, I'll bear those in mind.

Pat,
Sorry for not searching first. I've done a search and now have the answers I need.

Regards

Womble