Im trying to weigh up the options on my new engine and need some help :2Confused I\'ve got a 13b nikki manifold with a 6 port adapter coming from aus very soon and I\'m looking at using either the nikki on my 12a now or a single Throttle body with my Impco 300a on top.
The big nagging question is what size would i need on a stock ported 13b engine ? Looking on racing beat they say a dual 48IDA which would be 3619mm² while a single 60mm is 2827mm² and a 64mm is 3216mm². The thing that gets me is is the twin 48 a bit on the top limit of size because it fits in-line with a street-port and bridge-ported engine.
Cheers
Shaun
If you err on the small size Shaun you may lose out possibly on the top end but it should make drivability lower down better. Its going to be a learning curve anyway so you may as well walk before you run.
Kevin
Very true, I\'d probably air on the side of caution and go for the 60mm one. A lot of guys on ausrotary said its better for lower end and driveability if you have the smaller throttle body.
I\'d just like to remove as much clutter of the petrol carb as possible. Would like it to look as clean as possible.
Unfortunately with me not running on petrol the questions are definitely going to be a steep learning curve. Although anybody running a custom manifold would have the same issues if they aren\'t running the stock throttle body.
Shaun
Steep learning curves are good for the brain if not social life though Shaun all those hours spent trawling the web.
Kevin
http://www.rx7club.com/showthread.php?t=357916&highlight=60mm+throttle+body+13b
They say about 65mm but the response is a bit iff at low revs.
Looking at a single bore one of these:
http://www.jenvey.co.uk/drawings/S2000.htm
Its a 64mm one with a progressive pickup, slow on initial opening and faster at full open.
Shaun
hrs.......... lol more like days !!!!! Not good for the brain !!! Very interesting though in some respects.
Shaun
Got this today in the post :D Cost about 40quid in total. 65mm throttle diameter tapered to 70mm dia at the top :D
(http://img.photobucket.com/albums/v233/shaunwil/DSCF0177.jpg)
Shaun
nice, that is one dirty mouse shaun!
Mark
Thats an engineering mouse :Giggle
Quote from: BrettThats an engineering mouse :Giggle
it looks like it has been ported and skimmed for a smoother operation!
Mark
Wouldn\'t mind I now sit behind a desk most of the time on CAD. It was clean at one time in its lfe :Giggle
Shaun
Just to say my other mouse is very clean :D
(http://img.photobucket.com/albums/v233/shaunwil/DSCF0179.jpg)
Shaun
thats not a mouse that a mop for doing the car!!
Its a 3D mouse :D
Shaun
Right, Thought I\'d update this thread too on the progress in case somebody else ever trys the mad stuff i\'ve done.
The 65mm throttle is too small for the setup i have !! 1st tune of the car showed good fueling curves from the gas. However it only made 105bhp at the wheels. Looking at stepping the throttle size up to 80mm and trying again.
Car is super at low revs pickup is awesome. My clutch master and slave are a bit duff so can\'t tell completly yet on how she runs but it brings a big grin :D
Can\'t get them quite as cheap, guy on UK ebay sell new ones for about 80quid.
Shaun
good to see its getting there shaun, you need to bring it to pod now!
Mark
Once the 80mm throttle is on then oh yes :D
Shaun