Ok ive narrowed by drivetrain options to a
northstar with a 915
or
a GM 4.3 v6 with a boxster 6 speed
Ive seen the 4.3 done before but never a northstar.
Mind you the 915 trans is getting hard to find , or at least thats the way it seams...
Full Version: Drivetrain thoughts
I wouldn't do either one... But if I have to choose from your list, go with the Northstar for the cool factor.
Interesting choices . . .
4.3 - why bother, it's as much work as a V8'
915 - I don't believe it has any advantages over the 901 and it's a bunch of work to convert.
4.3 - why bother, it's as much work as a V8'
915 - I don't believe it has any advantages over the 901 and it's a bunch of work to convert.
Has anyone put in a boxster 6 speed successfully.
QUOTE(914nola @ Apr 3 2015, 09:25 PM) 
Has anyone put in a boxster 6 speed successfully.
I have. It bolts right to my Audi motor...
Will the boxster bolt to the audi v8?
A couple of folks have done the Boxster 6 spd in with an LS1- ask around. Also see if Kennedy makes an adapter for your Northstar. Being a GM, it may be already done thinking it's all in the family.
QUOTE(Bruce Hinds @ Apr 3 2015, 09:48 PM)
Will the boxster bolt to the audi v8?
Yes but you would be better to use the 01E. Same bellhousing pattern. The FWD Audi V8 uses the 01E 6 speed. You can find them for around $3500.
Why would you want a 4.3 they are nasty motors. Low reving crap power output and they sound like a asthmatic with emphysema
why 4.3 ?
Cuz I have one sitting on my garage floor.
And 300 HP from a 4.3 is easy as pie.
I do see the Northstar being much cooler with DOHC heads.
Under everything ive read the 915 can handle much more than the 914 transmission
Cuz I have one sitting on my garage floor.
And 300 HP from a 4.3 is easy as pie.
I do see the Northstar being much cooler with DOHC heads.
Under everything ive read the 915 can handle much more than the 914 transmission
If the 901 is treated well, it will handle power. 1st gear is weak. I ran a 500hp turbo rotary on a 901 without issue. I always made sure not to stab the gas pedal until I was in third gear.
The Boxster tranny ($3500) is the same transmission as the Audi/VW 012 tranny ($400). They are all made by Audi. The Boxster S tranny ($1000-$5000) is built by Getrag. This tranny is also available in FWD Audis for less money. The difference is the Boxster comes with linkage compatible with cable shifters.
Make sure you consider your chassis if you are putting 300hp in a 914. You will need suspension, wheels, tires, brakes, stiffening kit or roll bar, etc... This gets expensive.
There is also the respect factor. An American engine is fun but you will get sneers from most Porsche owners. 914 owners (NARP) are a little more forgiving. A Japanese engine (like a rotary) will almost get you laughed at. I can say with my Audi motor most PCA members seem to like it. With that said, the 914 chassis is a great platform for an engine conversion. I don't really give a fuch what people say so ridicule don't bother me.
I'm not sure how an engine choice can effect resale value. Like me, you will only be able to sell to another conversion owner or a newbie. Most 914 owners particularly like Porsche motors even if it's a conversion 6 cylinder. Buying a complete V8 conversion will most likely be cheaper than building one.
I bought mine for $7k (5 years ago) but that included: roll cage, stiffening kit, 930 brakes, suspension, sway bars, V8, etc. Since I bought it, I swapped in 3 or 4 different engine tyoes before settling on my Audi turbo motor. I absolutely love the Audi motor. I'm making about 325hp.
The Boxster tranny ($3500) is the same transmission as the Audi/VW 012 tranny ($400). They are all made by Audi. The Boxster S tranny ($1000-$5000) is built by Getrag. This tranny is also available in FWD Audis for less money. The difference is the Boxster comes with linkage compatible with cable shifters.
Make sure you consider your chassis if you are putting 300hp in a 914. You will need suspension, wheels, tires, brakes, stiffening kit or roll bar, etc... This gets expensive.
There is also the respect factor. An American engine is fun but you will get sneers from most Porsche owners. 914 owners (NARP) are a little more forgiving. A Japanese engine (like a rotary) will almost get you laughed at. I can say with my Audi motor most PCA members seem to like it. With that said, the 914 chassis is a great platform for an engine conversion. I don't really give a fuch what people say so ridicule don't bother me.
I'm not sure how an engine choice can effect resale value. Like me, you will only be able to sell to another conversion owner or a newbie. Most 914 owners particularly like Porsche motors even if it's a conversion 6 cylinder. Buying a complete V8 conversion will most likely be cheaper than building one.
I bought mine for $7k (5 years ago) but that included: roll cage, stiffening kit, 930 brakes, suspension, sway bars, V8, etc. Since I bought it, I swapped in 3 or 4 different engine tyoes before settling on my Audi turbo motor. I absolutely love the Audi motor. I'm making about 325hp.
QUOTE(Mike Bellis @ Apr 4 2015, 07:53 AM)
An American engine is fun but you will get sneers from most Porsche owners. 914 owners (NARP) are a little more forgiving. A Japanese engine (like a rotary) will almost get you laughed at.
True, and I actually like this part, when people kind of self-identify themselves.
QUOTE(DBCooper @ Apr 4 2015, 07:24 AM)
QUOTE(Mike Bellis @ Apr 4 2015, 07:53 AM)
An American engine is fun but you will get sneers from most Porsche owners. 914 owners (NARP) are a little more forgiving. A Japanese engine (like a rotary) will almost get you laughed at.
True, and I actually like this part, when people kind of self-identify themselves.
Me too! It's really all about the driving and making it fun. Value and pretty show cars are really nice, but if you can't drive it in the rain or snow why bother. Wait! I have to clarify here - the snow thing - I was in Colorado where they don't use salt!
Opps, I digress, back to the sneer thing - When I built mine too many years ago it was really a new thing and where I lived, PCA would have nothing to do with us, so any activities were strictly SCCA - they were fun!
The best experience, in this regard, was when I first put it together, it still had fairly narrow wheels and tires, a true sleeper. I'd pulled off the highway and a brand new 944 turbo pulled up along side. We were both going to turn left in both lanes, he rolls down his window and tells me my VW really sounds funny! We stayed together through his first gear and as he shifted to second, since I was already there I just put my foot down.
I often wondered if he took it back to the dealer and complained.
Well...
The Northstar don't fit so good because of the large dohc heads.
The 915 box isn't worth the expense to flip it.
If this is your first conversion then the 4.3 to the 914 box might be a good way to cut your teeth. Plus you will be up and running sooner.
You will throw a bunch of money at the Box6 for 2 extra gears and smoother shifting.
The Northstar don't fit so good because of the large dohc heads.
The 915 box isn't worth the expense to flip it.
If this is your first conversion then the 4.3 to the 914 box might be a good way to cut your teeth. Plus you will be up and running sooner.
You will throw a bunch of money at the Box6 for 2 extra gears and smoother shifting.
Click to view attachment
Some links for your perusal,a latemodel Caddy N* or castiron 3/4 350.
A good source of bs-free info on the mid placement of a 4-cam.
A few different installs with unique takes on mid power.
http://www.fiero.nl/forum/Forum3/HTML/000007-77.html
http://www.fiero.nl/forum/Forum3/HTML/000121-4.html
http://en.wikipedia.org/wiki/General_Motor...C2%B0_V6_engine
http://www.hotrod.com/how-to/engine/hrdp-0...v6-performance/
A simple install with a KEP bellhousing,more room up front,for turbos,etc.Heavy tho.
P#=1700 Chevrolet 90° V6, 3.8 & 4.3 Liter.
Shortened small block V8. Some Chev's use Buick engines so verify rear distributor (over flywheel).
https://www.google.ca/#q=gm+4.3L+aluminum+heads
What should be on top.
The more sophisticated engine of course is the Caddy,for a reasonable cost.Mated to a 4k$ 6spd Boxster tx you would have a decent combo.
P#8400 Cadillac Northstar & Aurora V8. DOHC 4.0 & 4.6.
Computer contolled. Easily damaged if overheated.
Either way it's a long process of building and customizing the 914 to a more powerful car with bigger brakes and a working cooling system that flows.
Reinforcement has to be considered and suspension mods made to compensate for the weight changes and distribution,a rear sway bar no doubt mandatory with the castiron choice.Have fun.
Some links for your perusal,a latemodel Caddy N* or castiron 3/4 350.
A good source of bs-free info on the mid placement of a 4-cam.
A few different installs with unique takes on mid power.
http://www.fiero.nl/forum/Forum3/HTML/000007-77.html
http://www.fiero.nl/forum/Forum3/HTML/000121-4.html
http://en.wikipedia.org/wiki/General_Motor...C2%B0_V6_engine
http://www.hotrod.com/how-to/engine/hrdp-0...v6-performance/
A simple install with a KEP bellhousing,more room up front,for turbos,etc.Heavy tho.
P#=1700 Chevrolet 90° V6, 3.8 & 4.3 Liter.
Shortened small block V8. Some Chev's use Buick engines so verify rear distributor (over flywheel).
https://www.google.ca/#q=gm+4.3L+aluminum+heads
What should be on top.
The more sophisticated engine of course is the Caddy,for a reasonable cost.Mated to a 4k$ 6spd Boxster tx you would have a decent combo.
P#8400 Cadillac Northstar & Aurora V8. DOHC 4.0 & 4.6.
Computer contolled. Easily damaged if overheated.
Either way it's a long process of building and customizing the 914 to a more powerful car with bigger brakes and a working cooling system that flows.
Reinforcement has to be considered and suspension mods made to compensate for the weight changes and distribution,a rear sway bar no doubt mandatory with the castiron choice.Have fun.
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