Home Made Plenum

[Ralph Wiggum]

the base plate of the plenum is threaded so the bolts stay in the plenum although I can take them out once welded but its a c*** of a job, I drilled out the thread on the manifold so it slips in and out and I can tighten it down with nuts from the underside of the manifold, how I was going to bolt it down was the biggest issues I had to work out but this seemed the best way

Since you seem too be fairly handy with the tig why not cut some small blocks (2 perth bolt) and tig these either side of the bolt head to lock the bolt. Heating and cooling of the plenum may cause you bolts too loosen and your going to be pulling out your hair if they loosen up and spin!

Option B would be too purchase some 19mm ally bar stock cut into suitable lengths, dirll and tap a blind hole in each one for the stud size you have choosen and weld the over the existing hole (drill out the thread in your lower plenum half obviously) Gauranteed air leaks with way.

[ISL33P]

something like this powerslide

[power_slide]

Yea like that... I had a look at the nitro option as suggested and wonder if much research has been done in to the intake flute lengths,

Sounds like I'm better off with stock for circuit racing

[Adam]

Last time I saw one of those tested in performed worse than stock.

Goldbullet was probably the first customer to use one and his expanded under boost when HPF was tuning it.

You'd expect more for $3.5k. Is that what they still sell for these days?

[IH8TOADS]

Keep the PCV entry away from cylinder 6. It's known to be a problem cylinder and the amount of oil that accumulates in the No. 6 runner on the stock manifold bothers me

[kartman]

Looks cool, I send any we make to Specialty Power Porting to get the flows matched. Last thing you need is flow differences that lean out certain cylinders.

[ISL33P]

I have the flow figures on another computer which is currently out of action. Variance is absolutely minimal at around 1-1.5% from lowest to highest flowing.

Any well designed plenum should not need power porting....but this is typical when using the standard runners and hence the power porting.

[power_slide]

@ISL33P - Did you do a dyno run before and after to see what the performance diffences were, Also what would the difference be if you increased the size of the plenum chamber? what size intercooler did you use with it?

[ISL33P]

the car made an extra 30-32rwkw with the same boost on the same dyno with off throttle response being very noticeable from the first drive. I done the full installations. It used a cheap a$$ chinese inntercooler 600*300*75.

Stock turbo, stock wastegate, just exhaust, injectors and tune.

[icer]

have you put somethign like a nizpro or plazmaman plenum setup swapped to the nitto and seen if there are any/much differences and is it worth the extra $2000+ margin in price?