ITB + manifold build

This was my point, it is very difficult to sort

Mind you it only matters on the road car, not important so much for a track only car

 

And you feel that you can comprehensively tune a map only on the road?
I've heard of someone doing this down in devon and im not convinced that you can properly set it up, you can map the smaller throttle openings well i think.

 

You cannot "see" the holes in the torque plot as the engine traces a line in front of you for a given AFR target or spark angle setting no. But you can get it damn close. Plus on the road, you will determine most of the engine's drive feel.
Things like the fore mentions tip in stumble or tip-in to desired throttle opening, cold start, temp compensation and addtional drive features (ECU dependant) can only be established on road load live as well.
Use the dyno to develop steady state map pionts with rpm held or WOT sweep or if the vehicle is far to powerful to live map on the road.

 

this is just how i do my mapping aswell, i allways map on the road unless its big hp stuff,then i will finish it on the rollers,

also if a engine is mapped to max torque at all throttle openings its horrable to drive on the road, its just to agressive,

the only way ive got it semi there is have load sites in the map of 0% 1% 2% 3% and 5% then the mormal 10% to 100% , but not all ecu's will allow that amount,

 

Yes. If all sites are mapped at MBT or LBT then the engine can make the car become undrivable. Worse if the powertrain is geared very short.

 

Coming back to the linked vacuums losing your individaulity of the throttle bodies this problem could be easily solved with a one way valve fitted into the line out from every body. You still get you vacuum built up for your brake servo etc but no feedback from other cylinders.

 

sweet jules! Can't wait to see these! Wednesday your getting your itb's out for the lads!

 

you cant beat a dyno for getting the main mapping done
sure some road test and trims, and a few iterations of cold start and warm up etc

having only had option of on the road mapping previously, I would not choose to do this now I have a dyno, even for sweep runs, and light throttle settings.. all the sensors in front of you strapped down, coffee in one hand.. lol

 

Heres a few pics of recent progress, its not mega sexy or complicated but it works and holds them perfectly.

 

Update!

 

looks very good, it looks like you've kept the spacing the same as the 16v inlet, how have you got around the linkages on the ITB's, I'm running the same ones but haven't worked out a hassle free way of connecting the linkages between each TB

 

You can just bend the lugs on the linkages between the throttle bodies to suit. The TBs are 80mm bore centres and the on the 16v head they are 88mm. Just bend each side 4mm to make them work perfectly.

 

Bend them!!? Nah just weld on 4mm wide tabs, is what i did and was easy enough.

 

And burn off the lovely cadmium protective coating.

Just posted to let folk know it was a simple option. Did both sets of GSXR TBs I have in a round 10mins.

 

There is a third way, add the tabes by drilling the linage and using nuts and bolts to hold them. Its almost the best of both.

I welded mine but in retrospect would now not and try to damage the coating so would drill and add tabs or try bending them, would be good to see how bending looks when done and how it affects the movement.

 

bending is ok surely? not seen em 1st hand, but these are bent to suit anyhows (on jenveys)

 

Bending is fine. I have actually only bent one side now that I see it again.
The tangs on the levers are actually longer than they need to be, so when bent the balancing springs and screws still sit perfectly on the tang.

Note CNCed 8mm spacers to space TBs out from 80 to 88mm.

 

Looks like the way to do it. I was thinking bending the two sides would put the adjustment screws at difficult to reach angles. This looks good.

 

It works for me. Even without a degree in engineering!

The CNCed spacers were a beauty though. I got all the dimensions with recesses and protrusions drawn up for the machining program and got a couple of batches rattled out in minutes. Longer stainless rods and jobs a good un.

 

Nice one, thanks for the advice guys, next question, would you fancy doing another set of spacers? If so what'd you be looking at for a set?