quad trottles differents on 20v

[NA Drifter]

Heard that the trottle body of 20v Silvertop got 45mm and the blacktop got 47mm?
IS there anychance that silvertop cameout with 47mm?

[MattrickMotorsport]

NO

[NA Drifter]

ic...
funny that i brought some came with a silvertop head and 47mm trottlebody on them.... might been swaped somewhere in it life.... also how can i tell if that is a silvertop head??... apart from the cover itself cos they interchance able....

[Mr Revhead]

it may be possible.....

there is a change in 9301...... and iv heard the later silver top ones are bigger than the earlier ones.... but the change maybe shape i cant remember

[MattrickMotorsport]

silvertop exhaust ports are smaller as far as i know

[spencer]

yea exhaust ports also blacktop has an open combustion chamber
like this


and the silvertop has squish areas like this badboy



should be pretty easy to tell! if the head is off

[RedMist]

The TB's are measured at the butterfly. The silvertop are 43mm and the blacktop 45mm. From memory they are 47 and 49mm respectively at the inlet. There are two different types of MANIFOLD on the silvertops and one only on the Blacktop. The Blacktop TB's are tapered in the floor of the TB itself then the taper continues through the manifold (head end is like a D with the cutout on the bottom, Silvertop retain the O shape). I very much doubt that Toyota ever created a set of 45mm TB's and yet another manifold for the silvertop. Becides the taper would be all wrong unless Toyota pushed the butterfly's much further from the head.

The Silvertop manifold change is to do with the head end. It changes from an oval shape with a slot in it for the injector to a teardrop shape (which flows sygnificantly more).

In regards to exhaust ports, yes the Blacktop are dramatically larger (almost 20% bigger in volume) than the Silvertop.

Inlet side of the Blacktop is also dramatically larger, and flows fantastically well, but velocity is crap and the pathetic port deviders push all the air through the center valve! Sounds like a job for a grinder and a Turbo!

They also revised the cam bucket oil retainers, Blacktop allow for more lift before you have to grind out the bucket retaining lip.

[vvega]

blacktop and silvertop airbox are not interchangeable
the blacktop is massive in compasision
also the blacktop trumpets make the silvertop ones look like toys


v

[RedMist]

I thought the Blacktop ones were terrible... rubber!! I'd love to have a camera in the airbox to watch them collapse under heat and vacuum.
The airbox is much larger in capacity, however remember Heimholtz, they are attempting to alter the RPM to make peak power!

[yolk]

RedMist,
I'm running a hybrid silvertop ie blacktop wiring with blacktop head and blacktop plenum with blacktop ITB's and recently went for a dyno test and I got more power than an almost stock silvertop 20v and my power and torque at the low revs are way much better than his .. any idea as to why ? Both of us has the usuall filter/exhaust mods but he is running fgk or was it hks extractor while i was using the stock 20v extractors

[vvega]

I thought the Blacktop ones were terrible... rubber!! I'd love to have a camera in the airbox to watch them collapse under heat and vacuum.
The airbox is much larger in capacity, however remember Heimholtz, they are attempting to alter the RPM to make peak power!

totally agree
i think the trumpets are a afterthought (how the $&#$% do you get a resonance from rubber :S) and the airbox is just strait out to large

have to remember with quads the airbox is not a plenum
more a still airbox

dont like the shape ethier but hey thats another disscussion


v

[MattrickMotorsport]

so what do you guys suggest to use other than factory trumpets and airbox which will still be able to kepp or improve horsepower?

[NA Drifter]

thanks for the replys guys...
I'll go and check again what stuff i got.... is hard to compare(between the 2) since I only have an item here.. which I'm trying to find out what are they more technically.
with a ruler, the inlet and outlet of the quad trottle are 47mm. the gasket is 50mm. The "trumpet" is bend shaped and 2 is redish colour, and 2 is black. they all plastic. and got different numbers on them 1#4# and 2#3#.. something like that.... Will look on the head to check if it is a Silvertop head or a balcktop... thanks for the pic ke70wagon20v

[RedMist]

NA Drifter - It's a silvertop head.
MattricMotorsport - I've the benefit of having a custom made car so I have no firewall restrictions. Although I currently run a factory airbox and trumpets I have an airbox waiting to be dynoed. I run 70mm straight trumpets however I have a 50mm spacer between the manifold and the 16 valve head so my total intake length is approx 17 inches from valve to bellmouth. For intake length tuning look here.. http://www.grapeaperacing.com/GrapeApeR ... ystems.pdf
When you tune intake length try not to boost max HP but fill a torque hole and flattern your curve within your RPM range. You'll find it makes a much faster race car.

VVEGA - Too bloody right!

Yolk, interesting. The silvertop pistons aren't as good as the blacktop and I had thought (until you made your post) that the reason the Blacktop was more powerful was the raise in compression. I'm not an open combustion chamber fan, especially as it's hard to promote swirl with 3 inlet valves (so I don't think that's why your faster) You do have a bigger intake cam which will account for some power difference. But it might be car weight or even driver. I think the other power advantage you have is the exhaust manifold. You'll probably find you develop more mid range torque which will make your car faster, whereas most aftermarket extractors are designed to make peak HP to show off figures (which is little more than rice) Would be interesting to dyno!

[yolk]

RedMist,
I have created a new topic regarding this hopefully you can share your experience and give some insight on the matter. Thanks

[NA Drifter]

checked the head... look like a Silvertop.....
so, i guess the quads also belong to the silverstop engine too... just 2mm bigger..?

I don't think the silvertop head is any use to me... so if anyone looking for one, please do let me know...

[RedMist]

Could be 47 and 49mm mouth dimentions. I can't remember off the top of my head.