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100mm T/B + GREDDY PLENUM (RB26) does it work???


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Hey all...

Does anyone know if using a 100mm throttle body with the Greddy plenum for an rb26 will work well???

Will the flow be enough to support over 1000hp??

I have heard that the greddy plenum has been designed for the 6 butterflies but will it still be effective with the 100mm T/B??

Need information about this asap...

Cheers

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I dunno about the extent of your testing, but i know that nissan has gone out of their routine to do a 6 butterflies job for the gtr for response, as for other manufacturers that uses multi throttle bodies on there cars with great results are The m series BMW all porsche-ferraris-maseratis-lamborghinis-lotus-elfins- and most of the alfas and lancias.

the reason the japanese went for the single t/b is that originally they had issues with tunning it as the smaller t/b as the airspeed and pressure some how cause anomalies between cylinders which then inturn made it much harder to tune and a way to solve the problems was go a big single t/b. But Time have taught them a few thing most notably is MOTEC which nails the anomalies on the head, The reason single t/b are still around cause old habits are hard to kick, and if it's on the shelf why not use it.

But as S/K said is true, instant response is a non event for a drag car.

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Multi throttles is old hat and race teams know the problems they cause and have slide and barrel setups to now. Wol,f Autronic and Motec all have TPS V MAP for the pulsing problems in tuning but they cant solve the turbulance and restriction this old skool setup causes in ports and as modern multi throttle setups cost HUGE single is next best.

My tested opinion but feel free to have your own.

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As usual Steve is right, there are better methods than horizontal throttle butterflies. The SuperTourers use barrell throttles so that there is no spindle in the way at WOT. The V8Dinosaur uses slides, again so that there is no spindle in the way at WOT. I do some work on a car that has verticle spindles, they line up with the port divider between the 2 inlet valves. It shows a small gain in power over the horizontal spindles. The current generation of BM's don't even have a throttle as such, they use variable valve lift to control engine power.

Barrell throttles are expensive to make. Slides don't work very well on forced induction engines, the pressure on the closed slide makes it very difficult to open them. Changing an RB to verticle spindles would be a nightmare to equalise the flow to each cylinder, it is hard enough on a 4 cylinder.

But what design of throttle control device is really secondary to this discussion (which we have had a number of times in numerous threads), the real question is how big and where.

The bottom line for me is pretty simple;

1. For a circuit race car, multiple throttle butterflies close to the inlet valves give better response than a single throttle body many litres of airflow away. This is both logical and well proven in the field. Up to the power levels we have used (~650 bhp) there is a noticeable loss of instant throttle response when a single butterfly is used. I have seen the same result on SR's as well as RB's.

2. For a drag car, I would be chasing every single horsepower, so removing the turbulance and restriction of the multiple throttle butterflies would be on my list. But I am not sure where it would rank on that list, there are so many other things that would rank higher. I have seen a number GTR's in Japan run low 9's using the standard throttle bodies and standard plenums. Theo here has run many, many 9's with the standard throttle bodies. So if I was building a 9 second capable car, then there is an argument that says spend my time and money on the other things on the list first. If I was building an 8 second car, then there is really no question, I would have a large plenum and a big single throttle body. And it would feature pretty early on my list.

3. For a road/combo car I see no reason to give up even the slightest amount of throttle response. Personally I hate lethargic engines (or chassis for that matter), they need to respond to my inputs instantly. Probably comes from too many laps around circuits.

As Steve said, everybody is entitled to their opinion and that's my 20 cents worth:cheers:

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If 1000+ horsepower is the goal, a single large throttle body is the way to go. When that much air is being forced into each runner, each individual throttle butterfly and post is a great restriction for such a small area. Like we discussed earlier, I would be more than happy to help you out with a custom plenum. I could machine it to fit any throttle body. I would also knife edge the butterfly blade and rework the butterfly post for you to allow for even greater cfm. I'm not sure what price I quoted you, but pm me again and we'll talk. Odds are it was too high. Like I said before, I would see to it that it out-do anything else out there.

To give you an idea of what it could look like, heres a plenum were doing for a 1000+ hp supra.

http://www.supraforums.com/forum/showthrea...threadid=250040

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If 1000+ horsepower is the goal, a single large throttle body is the way to go. When that much air is being forced into each runner, each individual throttle butterfly and post is a great restriction for such a small area. Like we discussed earlier, I would be more than happy to help you out with a custom plenum. I could machine it to fit any throttle body. I would also knife edge the butterfly blade and rework the butterfly post for you to allow for even greater cfm. I'm not sure what price I quoted you, but pm me again and we'll talk. Odds are it was too high. Like I said before, I would see to it that it out-do anything else out there.

To give you an idea of what it could look like, heres a plenum were doing for a 1000+ hp supra.

http://www.supraforums.com/forum/showthrea...threadid=250040

I reckon the toaster would work better :D .....can i order one of those off you?:)

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