Streetable Eight Stack

[PaulProe]

Randy,
You do understand, Want and Need are both four-letter words and completely interchangeable. inj

There are a couple differences in the EightStack and the TBI. The EightStack, the injectors are inside the castings that replicate the body of a Weber 48IDA. The injectors are situated above the throttle plates and inject onto the mostly closed throttle plate at idle and lower throttle openings. That presents a little more work when setting up the system and the Accel/Decel settings. The injectors are not easily accessible as they are buried inside the throttle bodies.

The TBI system has the injectors on the outside of the throttle bodies, held in place by the fuel rail. They inject below the throttle plates onto the backside of the valves. More like a modern-day injection system.

The EightStack is about 8% more in price. The TBI is slightly easier to tune. If you are after all-out performance, the TBI is the better choice. If you are after period-correct looks, the EightStack is the better choice. Either will wow the typical on-looker.

These are shot's of my current build using the EightStack. I prefer a period correct look,

Paul

 

[Randy Folsom]

Randy,
You do understand, Want and Need are both four-letter words and completely interchangeable. inj

There are a couple differences in the EightStack and the TBI. The EightStack, the injectors are inside the castings that replicate the body of a Weber 48IDA. The injectors are situated above the throttle plates and inject onto the mostly closed throttle plate at idle and lower throttle openings. That presents a little more work when setting up the system and the Accel/Decel settings. The injectors are not easily accessible as they are buried inside the throttle bodies.

The TBI system has the injectors on the outside of the throttle bodies, held in place by the fuel rail. They inject below the throttle plates onto the backside of the valves. More like a modern-day injection system.

The EightStack is about 8% more in price. The TBI is slightly easier to tune. If you are after all-out performance, the TBI is the better choice. If you are after period-correct looks, the EightStack is the better choice. Either will wow the typical on-looker.

These are shot's of my current build using the EightStack. I prefer a period correct look,

Paul

Paul, Thanks much for explaining the differences. This is a really hard decision. Both these systems look awesome.

 

[Dave Hood]

The Borla set-up (bottom photo above) is what I have on my car. It works very well. My only complaint was that the flange at the top of the trumpets did not accommodate the KN Filters I wanted to use. So I had to swap them out with trumpets similar to the top photo that have a rounded top edge.

 

[Randy Folsom]

The Borla set-up (bottom photo above) is what I have on my car. It works very well. My only complaint was that the flange at the top of the trumpets did not accommodate the KN Filters I wanted to use. So I had to swap them out with trumpets similar to the top photo that have a rounded top edge.

Dave, I probably was not clear. Both pictures are Borla systems. I wonder if Prestige can order the 8-Stack system from Borla with trumpets from the EFI ITB system. Since air filters will largely hide the trumpets, the difference in looks should not matter that much. I will give Prestige a call. Which K&N filters did you use? Cheers, Randy

 

[Andrew Robertson]

On the subject of filters, I was looking through a datalog the other day from recent fang on the motorway. I don't usually pay much attention to MAP readings because I use Alpha-N fueling but I do have a MAP sensor logged. When wide open starting at about 3k my MAP reading dropped steadily from a flat line at 100kpa to 96-97kpa at 6600. I haven't done a back to back test yet but I'm pretty confident that will be pressure drop across the ITG filters rather than losses in the manifold. At 3-4% loss of air density I'm probably giving up 15-20hp. Those mesh tea-strainers or small individual filters are probably worse - anyone measured them?

Cheers, Andrew

 

[Ian Anderson]

Webber inlet flow study

Since I am basically snowed in, and recently got acces to a CFD package, I thought I would do a little investigation into the inlet side of everyones favorite form of fuell addition, the webber carb. CFD stands for Computational Fluid Dynamics, or as one of my proffessors likes to call it...

www.gt40s.com

Some fluid dynamics from a while back!

Ian

 

[Brian Kissel]

Ian, THANK YOU for reviving this 20 year old thread. For whatever reason, it appears that I did not save it to my files. I certainly will this time. Excellent reading.

THANKS again !!
Regards Brian