Found this little beauty for 1500 bucks!, 1974 Porsche 914 build Options

[Andyrew]

That looks really nice!
I'm in the process of designing a hood vent for my LS build and I'm curious to know if you calculated the area of the hood vent opening and accounted for the non-open space of the louver panel.
I'm not challenging the design, just trying to learn as I understand you want to end up with more open area in exit than the intake opening.
Maybe others with knowledge ( @Andyrew @ChrisFoley ) can chime in?

Again, it looks fantastic! You're going to have quite the hot rod there. Can't wait to see it come together.

Hood vent is far more efficient at expelling hot air than going through the fenders.

The math suggests you need 50% more outlet size than inlet size.

How big is your radiator?

[billium01]

That looks really nice!
I'm in the process of designing a hood vent for my LS build and I'm curious to know if you calculated the area of the hood vent opening and accounted for the non-open space of the louver panel.
I'm not challenging the design, just trying to learn as I understand you want to end up with more open area in exit than the intake opening.
Maybe others with knowledge ( @Andyrew @ChrisFoley ) can chime in?

Again, it looks fantastic! You're going to have quite the hot rod there. Can't wait to see it come together.

Thanks a bunch! No I didn't do any calculations for the hood exhaust. The location seemed to fit between the hood structure underneath while still maximizing size as well. My metal guy said he's seen lots of hoods go wonky after changing underlying structure. The grill is just for aesthetics but will possibly end up coming out so as not to restrict air flow. Might see about making the gurney flap bigger too. I'm sure it'll take some fiddling. Somebody in a later post mentioned the exit should be 50% bigger than the intake. I'll see about measuring the exhaust area. Today I found an old school lower valance from Erik at carquip. They are super nice btw. Anyways my guys are going to make the opening for the radiator later this week. I'll definitely post some more. Thanks again! Curious to see what you will come up with!

[billium01]

That looks really nice!
I'm in the process of designing a hood vent for my LS build and I'm curious to know if you calculated the area of the hood vent opening and accounted for the non-open space of the louver panel.
I'm not challenging the design, just trying to learn as I understand you want to end up with more open area in exit than the intake opening.
Maybe others with knowledge ( @Andyrew @ChrisFoley ) can chime in?

Again, it looks fantastic! You're going to have quite the hot rod there. Can't wait to see it come together.

Hood vent is far more efficient at expelling hot air than going through the fenders.

The math suggests you need 50% more outlet size than inlet size.

How big is your radiator?

Thanks! my radiator is an AFCO 80133N. The core is 22.25" wide 15.75" tall and 2.25 inches thick. Double pass radiator with the cap deleted. Thanks for the info too. Going to look into the underlying math for the rest of the design.

https://www.speedwaymotors.com/AFCO-80133N-...nlet,39512.html

[billium01]

LS6 out of a Cadillac CTSV.

Nice !! the shop down the road from me does a bunch of LS swaps,,
they went LS fest in Vegas last weekend there was a red 914 autcrossing

Very cool. Thanks! Cant wait to get it out onto a track.

[ConeDodger]

Just noticed this. Wow! (IMG:style_emoticons/default/welcome.png)

[jd74914]

That looks really nice!
I'm in the process of designing a hood vent for my LS build and I'm curious to know if you calculated the area of the hood vent opening and accounted for the non-open space of the louver panel.
I'm not challenging the design, just trying to learn as I understand you want to end up with more open area in exit than the intake opening.
Maybe others with knowledge ( @Andyrew @ChrisFoley ) can chime in?

Again, it looks fantastic! You're going to have quite the hot rod there. Can't wait to see it come together.

Hood vent is far more efficient at expelling hot air than going through the fenders.

The math suggests you need 50% more outlet size than inlet size.

How big is your radiator?

Thanks! my radiator is an AFCO 80133N. The core is 22.25" wide 15.75" tall and 2.25 inches thick. Double pass radiator with the cap deleted. Thanks for the info too. Going to look into the underlying math for the rest of the design.

https://www.speedwaymotors.com/AFCO-80133N-...nlet,39512.html

I've never gotten where people get the 50% bigger outlet thing from. Radiator outlet duct sizing is a somewhat contentious topic for a lot of aerodynamics engineers even. Lots of disagreement over whether is should be huge or a converging duct (vs. radiator size). Huge is old school, smaller is new school. The overall idea is you want lower pressure on the outlet-huge potentially gets you higher dump-to-ambient efficiency, smaller has lower pressure due to flow velocity. Keeping the same velocity throughout would mean a 33% larger duct than inlet.

Car progress looks great! (IMG:style_emoticons/default/beerchug.gif) Did you make the solid (surface?) model?

[billium01]

That looks really nice!
I'm in the process of designing a hood vent for my LS build and I'm curious to know if you calculated the area of the hood vent opening and accounted for the non-open space of the louver panel.
I'm not challenging the design, just trying to learn as I understand you want to end up with more open area in exit than the intake opening.
Maybe others with knowledge ( @Andyrew @ChrisFoley ) can chime in?

Again, it looks fantastic! You're going to have quite the hot rod there. Can't wait to see it come together.

Hood vent is far more efficient at expelling hot air than going through the fenders.

The math suggests you need 50% more outlet size than inlet size.

How big is your radiator?

Thanks! my radiator is an AFCO 80133N. The core is 22.25" wide 15.75" tall and 2.25 inches thick. Double pass radiator with the cap deleted. Thanks for the info too. Going to look into the underlying math for the rest of the design.

https://www.speedwaymotors.com/AFCO-80133N-...nlet,39512.html

I've never gotten where people get the 50% bigger outlet thing from. Radiator outlet duct sizing is a somewhat contentious topic for a lot of aerodynamics engineers even. Lots of disagreement over whether is should be huge or a converging duct (vs. radiator size). Huge is old school, smaller is new school. The overall idea is you want lower pressure on the outlet-huge potentially gets you higher dump-to-ambient efficiency, smaller has lower pressure due to flow velocity. Keeping the same velocity throughout would mean a 33% larger duct than inlet.

Car progress looks great! (IMG:style_emoticons/default/beerchug.gif) Did you make the solid (surface?) model?

No I bought the model and know enough to tweak things in Rhino 3d. In the books I've read little is mentioned on duct sizing. Yes they do say have a lower pressure creating flap of some kind at the exhaust. From what I know about aerodynamics air through a beurnouli tube should have constant flow with the speed of the air increasing and pressure decreasing when the air is made to go through the narrowed throat. I wonder if the gurney flap accomplishes the same thing as upsizing the duct exhaust. The guys at renegade said they cut 4x6 holes in the wheel wells at a minimum to get the radiator to flow sufficiently. I'm thinking having a channeled duct with baffleing would be a better and more efficient approach. Like how it looks too. My duct in the hood measures 4.5" by 23.5 inches. Looking at making the inlet the right size now. Thanks for the info.

[billium01]

Some tilton pedals will be nice for the quick heel toe.

[billium01]

It appears the 911 rack and pinion input shaft is a bit shorter than the 914. Is that what's going on here? There isn't enough spline to attach the u joint to. Always heard the 911 would bolt right up to a 914 and that the front suspensions were interchangable.

PS not sure why my pics are sideways. If you click on them they show right side up.

[billium01]

So gonna stick with this radiator exhaust minus the grate. Going to open up the bumper and lower front valance for the intake and form the duct work out of aluminum. The radiator is going to mount to the down bars via some tabs and triangulated tubes. More to come.

[billium01]

Got one of the rear hubs that work well for a 5 lug conversion with higher horsepower. It's a rear hub off a 1969 through 1973 Porsche 911. These hubs can be identified in part by the flat flange on the stud side of the hub which has the threads. Not sure if there's any other differences. They are getting harder to find all the time from what I hear. Parts Heaven sent me this one and some bearings as well. Was also able to stop by Carquip in Boulder CO the other day and pick up an old school front valance. Both those outfits have super nice people and are good places to source parts. Just keeping an eye out for another hub.

[Luke M]

It appears the 911 rack and pinion input shaft is a bit shorter than the 914. Is that what's going on here? There isn't enough spline to attach the u joint to. Always heard the 911 would bolt right up to a 914 and that the front suspensions were interchangable.

PS not sure why my pics are sideways. If you click on them they show right side up.

The 911 racks (69-89) will bolt up to the 914. The steering shaft from 911 to 914 are different. At least by the part numbers they are..

914 : 91434721000
911 : 90134721004

You may need to pull the rack to swap the shaft out for a 914 one.

[billium01]

It appears the 911 rack and pinion input shaft is a bit shorter than the 914. Is that what's going on here? There isn't enough spline to attach the u joint to. Always heard the 911 would bolt right up to a 914 and that the front suspensions were interchangable.

PS not sure why my pics are sideways. If you click on them they show right side up.

The 911 racks (69-89) will bolt up to the 914. The steering shaft from 911 to 914 are different. At least by the part numbers they are..

914 : 91434721000
911 : 90134721004

You may need to pull the rack to swap the shaft out for a 914 one.

Thanks! I found this thread on 914world too. Says in addition to input shaft length being different between 914 and 911 racks, the hardness of the 2 rack splines are different as well.

[billium01]

Mocking up the radiator and mounts.

[billium01]

[billium01]

Been scouring the internet for wheels. Looked at many manufacturers and finding the right size with the appropriate offset, bolt pattern etc has been a challenge. So far I think I like these the best. Might do 17" fronts and 18" rears.

[dan10101]

Been scouring the internet for wheels. Looked at many manufacturers and finding the right size with the appropriate offset, bolt pattern etc has been a challenge. So far I think I like these the best. Might do 17" fronts and 18" rears.

I feel your pain. Still looking for my wheels. But, I like those Momo wheels.

LS6 and Boxster S trans. I'll be watching closely!
Keep up the great work. It's looking to be a very nice build.

[billium01]

Been scouring the internet for wheels. Looked at many manufacturers and finding the right size with the appropriate offset, bolt pattern etc has been a challenge. So far I think I like these the best. Might do 17" fronts and 18" rears.

I feel your pain. Still looking for my wheels. But, I like those Momo wheels.

LS6 and Boxster S trans. I'll be watching closely!
Keep up the great work. It's looking to be a very nice build.

Thanks! Yep type in 5x130 and watch the selection drop sharply. These are called the heritage 6 wheels. The prices are quite resonable too. Lots of history there and look cool. The ratios on the boxster S trans are pretty close. A bigger overall rear tire diameter will give it a little more speed. Always like the look of staggered wheel sizes. It'll give it a slammed raked stance and plenty of ground clearance too.

[Andyrew]

Always like the look of staggered wheel sizes. It'll give it a slammed raked stance and plenty of ground clearance too.

(IMG:http://www.914world.com/bbs2/uploads_offsite/a1.sphotos.ak.fbcdn.net-172-1321246691.9.jpg)

Agreed.

[billium01]

Always like the look of staggered wheel sizes. It'll give it a slammed raked stance and plenty of ground clearance too.

(IMG:http://www.914world.com/bbs2/uploads_offsite/a1.sphotos.ak.fbcdn.net-172-1321246691.9.jpg)

Agreed.

Looks awesome! Is that your car?