If you had to do it all over again..., convert to a flat 6 or v8 Options

[stevenhaas]

Ok!!! So here is the million dollar question!!!! If you had to do it all over again would you convert to a flat-6 or a V-8? What is easier to convert? Seems like the V-8 maybe a little cheaper. However it seems like you have to cut your firewall out… is that also true? (Please note I am no wheres close to it yet but I need a plan!)

What Trans is the best to go with? I was think of a 73-76 side shift 901 with a billet heavy duty intermediate plate from a 70-72?

(this would be built as street car… NO-auto cross….)

[914GT]

A Chevy V8 conversion is relatively easy and straightforward for someone who's done it before, and has used a tried-and-true set of conversion parts, whether those have been purchased as a kit from the various suppliers (RH, DH, etc.) or built by the person doing the conversion. But for a first-timer there's a learning curve, which is further complicated if your're experimenting on your own (home-brew radiators, water pumps) or trying to save money. What I'm trying to say here is that once you have a well-performing design, you can improve upon it and/or duplicate it fairly easily. You learn from your mistakes the first time. The V8 cutouts to the firewall are minimal, to clearance the distributor. The smaller distributors do not need as big a cutout as the GM HEI unit. A small cover is built to close the opening.

[tat2dphreak]

if money was no object... I would go 6 (big 6) or a Raby 4...

I wouldn't put a wasser in my car... that's just me. the Chebbies are hella fast, I'm sure... but I don't want one. if I wanted a SBC, I'd have a camaro... probably on blocks, in front of a trailer... like most of them are (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

no, I would love to do a chevelle 396 resto, but a chebbie engine in a 914 is just not what I want.

[riverman]

QUOTE (stevenhaas @ Apr 26 2005, 10:54 AM)

What Trans is the best to go with? I was think of a 73-76 side shift 901 with a billet heavy duty intermediate plate from a 70-72?

Sorry, slight hi-jack (still on topic though).

Can you give some details on the heavy duty intermediate plate on the early transmissions? I am doing a V8 conversion and I happen to have a few trans laying around (2 side shifters and one tail shifter). I have read in other places that the weak point of the 901 tranny is the intermediate plate, but I had no idea that the early transmissions had a beefier one.
Does the intermediate plate you're refering to come out of a tail shifter and are they a direct swap?

[MattR]

Im not sure I wouldnt go with a 4 again, if i could do it all over. I was looking for a driver with good milage, quiet, and simple. Yeah, i ended up spending $3k on doing a 2056 "right" and it wont be some rediculous six or v8, but the 8s ive seen arent very reasonable for a daily driver, which is what my 914 is.
If I had a project/fun car, I'd go six. No questions asked.

[Kerrys914]

Who has done BOTH conversions? (IMG:http://www.914world.com/bbs2/html/emoticons/idea.gif)

From my reading on this topic the two cars are VERY different. To me is seems like the better bang for the buck is a SBC V8 (install and maintenance).
BUT
the flat 6 has a nice appeal to it and you can never go wrong with a nice SIX in your teener (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)


Either way (IMG:http://www.914world.com/bbs2/html/emoticons/driving.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/driving.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/driving.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/driving.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/driving.gif) like you stole it (IMG:http://www.914world.com/bbs2/html/emoticons/aktion035.gif)

[stevenhaas]

QUOTE

I would go 6 (big 6) or a Raby 4...

My first thoughts where to go with a Raby 4. I just am not sure if 200 hp is enough.. I know that doesnt sound right... "Like what does this guy want???" so ... Here is what I want!

I want to beat a GT Mustang or Vette. I want to be able to do 140 mph if I want. I did email Jake about one his motors asking questions. I just really dont know. I have always had old Z28's with LT1's, 6.6 Trans Am a corvette or 2 along the way. I want the car to be quick and fast. A souped up 4 mayb e alll i need.

Cost is something that is important but if took me another year or so to get the right car togather then I would take the time. The engine cost between Jakes 4 and a flat 6 from Mes... are about the same cost. (240 hp) it is only 3K for a turn key v-8 with 330 hp.... see my delema??? I mean the best thing would be the four.. it is the easiest to do! but I have never been in a 914 with 240 hp nor raced agaisnt one. Dont get me wrong... I am older dude (40 this year! (IMG:http://www.914world.com/bbs2/html/emoticons/barf.gif) ) and I have no intensions of racing everynight, but I do want to blow away the young punk next to me when I have to!

[MattR]

If you want a drag car, dont buy a porsche.

Remember, the 901 gearbox isnt designed to handle lots of HP, so you're looking at a 915 tranny to handle the power, which is expensive.

[stevenhaas]

Again.... I am not nor do I have intension of taking it to the drag strip. I simply want that type of power. If I am at a light and some kid wants to run it, I want to win. Hell my wife is the same way... she drives a big old caddy and wil nail it when the light turns green if some one is trying to push her out. I guess what I am trying to say is I want the same acceleration or close to.... that of a new corvette. I have also have been involved with other folks that have twin turbos and thought nothing about racing light to light. everyone does a little drag racing from time to time. I am building the car for fun.

My understanding on trans is that a 901 would handle 330 hp.

[nebreitling]

a 901 will handle power depending on how it is applied. if you have a habit of dropping the clutch with the engine reved up in order to beat that 'vette or ricer next to you, it won't be long before you leave a nice pile of parts behind you....

doing what you're talking about (TORQUE!) is gonna take a serious tranny and axles. go for it, but leave the 901 at home.

[nebreitling]

btw, a 180hp hot 4 will seriously motivate your car, w/out needing to laden it with a radiator or a heavy V8. i doubt it would beat a vette off the line, but you should blow most of the imports away.

[tat2dphreak]

you probably COULD do 140 in a 200 hp 914, but why? it's a 2000 lb car it doesn't take much to push it, and 200 hp is mor than DOUBLE the stock hp (almost double the hp of a stock 6!) and very light!

there is NO where you can drive any car at 140(legally)... and no where and no time you SHOULD!!

I have been in a car that was doing 145 ONCE... I won't do it again... it was a 87 300zx twin turbo... and that is a scary feeling to go that fast with no helmet and roll cage!

[ewdysar]

So I've got a V8. If you're gunning for new Corvettes on the street, a SBC is probably the lowest $ solution, though this is not a cheap undertaking. If you want to do it right, once the engine and cooling is in, you've got other things to address, brakes, susp, chassis and more rubber to the ground. Of course, any hp increases of more than 100%, should probably have all of those things considered.

The thing that I did not take into account before my conversion is gas mileage/range. One of Raby's 4's can keep your range around 450+ and I hear that Scott's suby conversion delivered more than 30+ mpg over thousands of miles. I'd keep that in mind if (when) I do it again.

For whatever reason, I consider a Raby 4 with 911 5 lugs as keeping the car stock (IMG:http://www.914world.com/bbs2/html/emoticons/screwy.gif)

Eric

[MattR]

Would you really want to do 140 in a 914? Have you done 110? These cars are aero limited.

If you feel comfortable at 140 in a 914, top speed is all gearing. HP just helps you get there faster.

[MattR]

QUOTE (stevenhaas @ Apr 26 2005, 09:26 AM)

My first thoughts where to go with a Raby 4. I just am not sure if 200 hp is enough..

http://www.filebox.vt.edu/users/anbowden/Bluebonic.AVI

~ 200/200 at the wheels.

[stevenhaas]

well to be honest... no I have never done 140 in a car... (156 on motorcycle ...hehhehehe)

Suspension wise, I have full intension converting the suspension over to a complete 911 front end and doing heavy springs in the back along with big brakes whether I go with a big 4, flat 6 or v-8.

[anthony]

I think the major flaw in many conversions is the lack of planning for the transmission and gear ratios. With a typical 3.2L six conversion (230hp), ideally you probably want a 915 transmission with a limited slip, and Wevo treatment. If you want to win drag races then some shorter gears would be in order. (This is easily a $8K upgrade.) This is especially true if you are staying with a narrow bodied car and 205 tires.

With a V8 conversion you ideally want to go with the 930 turbo transmission. You probably also have to tweek gears if you want a drag racer since the 930 transmission has a such a tall 1st gear.

[stevenhaas]

damn, looks pretty quick!!!

[nebreitling]

i've seen 150 and 160 mph in cars more than a few times (IMG:http://www.914world.com/bbs2/html/emoticons/cool.gif) , and depending on the car, it doesn't have to be a completely puckered experience. however, at 100+, my 914 starts feeling a little twitchy and light. but i think that with the right suspension, chassis, tires, and aero development, a 140mph 914 should be no big deal.

but then maybe it ain't really a street car...

[lapuwali]

Following up with Anthony's thoughts, the 914 gearbox is very "short". With just 140-150ftlbs of torque, first gear becomes mostly useless, it's so short. My first 914 had a 2.4 911 engine in it, and it would spin the tires in first WITHOUT popping the clutch. Just start slow, roll on the gas, and by half throttle, the tires would just light up. A Big Four or a Six will also tolerate (perhaps even prefer) the high revs at freeway speeds you get with the 914 gearing, but a V8 will not. Most SBCs like to cruise around 1700-2000rpm at freeway speeds, not 3000-3500.

As for how much is "enough", a little math will tell you what you need to know: 2000lbs with 200hp = 10lb/hp. A Z06 Corvette weighs 3200lbs, and makes about 380hp, or 8.5lb/hp. An '05 Mustang GT weighs about 3500lbs, and makes 300hp, or 11.5lb/hp. Thus, a 200hp Big Four will put you squarely between those two. Note that a Six will weigh more than a Four, and a V8 still more. Also factor in chassis stiffening and bigger wheels and tires.