1984 throttle body upgrade / paint

[jim ross]

Whats up 928 lovers?..i just finished up my little project...installing a 1985 throttle body in my 1984 engine..and inspired by MPDANO i went ahead and painted spider black and refreshed the block with new paint as well. Thank God is started and runs super..only drove around the hood..didnt get out of second, i cant wait to get on the freeway! i dont know how many extra horse i got but i can feel just more overall power thru entire RPM range. "spider distributor' modified to 4" opening, throttle body was modified to hold throttle switches and linkage slightly modified...

[rhjames]

looks very nice--

know probably know this, but that fancy intake/air filter setup will be sucking in a lot of hot air....not what you want.

--R

[jim ross]

thanks! yes..but if you look to the right of the filter you can barely see a little white..thats a ram air intake from brake duct...and as we speak i am installing a heat shield...J

[Mrmerlin]

nice work your doing only suggestions I have,
make sure you have a new heater control valve and short hose, replace the fuel lines, ditch the alternate air intake and run the factory system it will provide cooler air and more of it.
The current system you will notice a power loss once the engine bay is hot
Goodluck with your project

[928worldwide]

Very Nice Jim,
now make a ram air with that tube and seal out the hot underhood air... The stock airbox is pretty efficient if you ask me (not that you asked) but since you already made something up, why not give it the best coldest air you can. If don't want to cut the hood, put it in the bumper cover. I'll give you a hood to use, to help if you want...Best scoop design? In the hood, not above it... like the factory did with the 962 intakes.

[MPDano]

Wow, nice job! The Throttle body and Spider Intakes look awesome. Glad this mod is helping. Get it on the freeway and report back.

[jim ross]

thanks everyone, heres a shot of the air filter w/ heat shield-white tube is ram air from brake duct in spoiler. any ideas how to seal off the filter even more?

[MPDano]

I wonder if you fully enclose that heat shield around the filter with its only input coming from the Brake Duct, if it would help better.

[chesireIsugaree]

This photo gives a better Idea of what we're looking at.

[chesireIsugaree]

It is well ahead of the motor, and at speed SHOULD take plenty of cold air..... But IMO nowhere near as efficient as stock...SOOOOO if you're gonna do it.... shoot cold air in DIRECT from outside. Either seal up the PVC and enclose the filter in a casement or build a casement on the hood and put in a scoop.... Or leave it like it is LOL

[XLR8928]

Looks really nice Jim! Let us know how it runs. Would have been cool to have a before, and after dyno run.
-Kerry

[jim ross]

Originally Posted by MPDano

I wonder if you fully enclose that heat shield around the filter with its only input coming from the Brake Duct, if it would help better.

that was my thought as well...im wondering what material?..more sheet metal..plastic..fiberglass? im thinking some fleible plastic rivetted to the shield, top and bottom.... leaving ends open---or as others noted a full enclosure to duct. HHHMMM..i wish there was enough clearance over the radiator to put a filter right in front. i did try placing a filter in the area inside the drivers side wing...great when dry...BUT there was NO way to keep it dry in rain because of leakage around the headlight.

[chesireIsugaree]

aluminum flashing roll $10.00 lowes
rivets...voila!

[chesireIsugaree]

That's the kinda stuff the factory did in the race program as it grew up, before all the realtime media pressure. Seen the shop photos of them building moby dick? A freakin mess all over the place.... greasy tools, bits and pcs everywhere.

[jim ross]

Originally Posted by chesireIsugaree

aluminum flashing roll $10.00 lowes
rivets...voila!

sounds super...whats the best way to cut it?

[jim ross]

Originally Posted by chesireIsugaree

That's the kinda stuff the factory did in the race program as it grew up, before all the realtime media pressure. Seen the shop photos of them building moby dick? A freakin mess all over the place.... greasy tools, bits and pcs everywhere.

sounds like fun! thats what its all about! what was "moby dick"? a 911--917 lemans racer?

[Mrmerlin]

Jim FWIW the ducting your making though it looks cool is going to reduce the amount of air that can reach the engine,
if you think about it the 2 ducts have a much bigger cross section than the single down tube just before the throttle plate.
Plus the mixing of the intake air near the throttle plate will be more uniform if the factory inlet is used
Others have done experimenting and also come to the same conclusion the factory air routing really is an efficient way to move intake air.
Additionally, your filter is also going to reduce its surface area creating more reduction in airflow
And the inlet to the engine compartment in thought may seem like a ram air it can in fact be charged to have the air moving the other way since the engine compartment will be filled with a higher volume of incoming air.
Lastly the metal tubing will also act as a pre heater to warm up the intake charge, plastic tubing will convey less heat.
Kind of a shame to make all these cool mods to the intake just to strangle it
Why not try doing some Dyno work with the factory inlet system the swap it over or viceaversa
Just a few observations on your plan.

More info and some videos of higher HP 928s
http://forums.rennlist.com/rennforums/928-forum/515653-ocic-dyno-day-videos.html?highlight=ott+intake

[XLR8928]

Originally Posted by Mrmerlin

Jim FWIW the ducting your making though it looks cool is going to reduce the amount of air that can reach the engine,
if you think about it the 2 ducts have a much bigger cross section than the single down tube just before the throttle plate.
Plus the mixing of the intake air near the throttle plate will be more uniform if the factory inlet is used
Others have done experimenting and also come to the same conclusion the factory air routing really is an efficient way to move intake air.
Additionally, your filter is also going to reduce its surface area creating more reduction in airflow
And the inlet to the engine compartment in thought may seem like a ram air it can in fact be charged to have the air moving the other way since the engine compartment will be filled with a higher volume of incoming air.
Lastly the metal tubing will also act as a pre heater to warm up the intake charge, plastic tubing will convey less heat.
Kind of a shame to make all these cool mods to the intake just to strangle it
Why not try doing some Dyno work with the factory inlet system the swap it over or viceaversa
Just a few observations on your plan.

More info and some videos of higher HP 928s
OCIC Dyno Day Videos - Rennlist Discussion Forums

I've noticed a lot of people eliminating the horns on the intake tubes. Is there any advantage to running a constant diameter hose all the way to the intake scoops atop the radiator?
-K

[Mrmerlin]

the reason for the air horns is to reduce intake noise it acts as a venturi decreasing the pressure and thus reducing the transmittance of noise

[morriss]

Sh** Merlin, you are a freakin' wizard. A walking 928 encyclopedia.