<p></p><p>Gracias</p>

 

That pic makes me wish I pained my block a dark grey or matte black, it looks super sharp like that.

I see lots of teeth sticking out from behind that damper, still 3 teeth on the intake cam?

 

TBD

 

Motor is in. Looks like John still has a few more days left on it. 45mm TWM. Can't wait to here this thing in all it's 13.5:1 big cammed, ITB glory.

 

 

Hubba hubba.

 

Looks nice! Just curious, how big are the 'big cams'? Is it somewhere around the specs of mine? 260+ duration @ 0.05".

My engine is only around 11.5:1 compression so I'm very interested to see your results.

 

Closer to 280 and 440 lift I think. They are one off. I will publish the specs when we publish the dyno numbers in a few weeks.

 

That must be advertised duration surely... I don't think I've ever heard of a cam spec'd at 280 @ 0.05".

I'll shut up and await the specs!

 

Hopefully you won't consider this going off topic.

So my mickey mouse ITB set-up is 42mm, and from head flange to trumpet the runners are 11" long in an un-opened '01 engine. It makes power out to 7400 at least. No real trade off in torque to a stock VTCS manifold but it takes off after 5700.

Would you consider the 45mm a better option for this engine? Or is 45mm a better choice for an engine that has better breathing capacity?

Have you found the TWM's better than the other's? By better I mean performance wise and by others I mean Jenvey, but Maruha also comes to mind.

Have you had any cars come in with the Club Roadster Special I have which is 20V Silvertops with Techno Toy Tuning manifold? Opinions? Or are ITB's just ITB's as long as you size them right?

Edit: looks like you chose to use the injectors on the head instead of on the TB. Have you found an advantage to having the injector closer?

 

We are not a repair shop so we don't see a constant flow of other peoples cars like you might think. We just sell parts and have an R&D facility out back.

Only our second ITB car and on the same set of TWM's. Our experience there is limited so I can't comment on comparisons with other ITB options.

Manifold was adapted from something else so you can ignore those bosses. Port fuel is best location.

Feel free to start a new thread discussing your build so more people will see it and can chime in.

 

ITB's require a lot of balance to get them to work right. Small changes in any variable can change the airflow harmonics. The sizing in both diameter and length will greatly affect torque and power at different points in rev range. Also, how well the head flows air will then change all the variables above, so really it entirely depends on the engine and target rev range as to which throttle body sizing and trumpet lengths will work. Even just adding filtration or airboxes changes things. The other issue is a race build like this will be different to a street build as you can pretty much disregard anything below 5000rpm.

Any ITB setup for race will ideally require lots of dyno time tweaking trumpet lengths to figure out the optimal power curve and tune out harmonic dips. Emilio's engine will no doubt need the largest diameter ports due to the flow of the head and large cams but total runner length will depend on the target rev range and whether the aim is for high 7000+ rpm power or more upper mid range power.

In Australia we can't really run longer trumpets due to the brakes getting in the way so if you run ITBs you're pretty much building an engine that will make power to over 8000rpm.

 

No dyno yet. Just a rough street tune. SOTP feels like about 190whp. We'll dyno it next week. Gonna autocross it down in San Diego this weekend and see if it ejects anything important. Pulls past 8 like it needs to. 6 x 4.875 gears for all the go kartitude.

Every Miata geek needs to drive a 200whp ITB car at least once.

 

<p>Will it be at Miatas@MRLS?</p>

 

That is the reason we built it

 

<p>Nice, i will definitely be lining up for a ride </p>

 

6 + 4.875 feels just right with ITBs and cams.
The 6-3 downshift needs some training though.
My build is not supposed to rev that high but the feeling when shifting at 8.2 is soo nice.

 

 

I'd love some short gears myself... Those freeway revs though because streetcar

 

They actually aren't as much worse than i thought they would. Only an extra 300rpm @ 80mph. I think i need to get on this train. Also found that 5.125 and possibly 5.38 are available. o_O

(That said i'm already rolling a 6spd/4.3 combo.)