ALFAGTV6.COM

[Mats]

Have a look at a Corvette transaxle + driveshaft/sideshaft joints and you will understand.

Absolutely massive.

[Micke]

Again not Alfa related but the Poosch transaxles seem to keep the smoke inside even under power. The 951 box is very difficult to mate with Alfa's DeDion but the 928's is much easier.

I helped a friend with his 951. We dynoed it a couple of weeks ago and it's not running well yet. Has just under 400 hp. In this start up phase he's running 1.2 bar boost only.

My point in this is that the weight is more than a GTV and this is how an Alfa will run with true (engine) 350 hp.
http://www.youtube.com/watch?v=XLhA8cYD2IY

[ar4me]

The original poster didn't specify, but I assume this is:
1. for a street car
2. needs to pass CA smog (at least the sniffer)
3. needs to run on lousy quality CA "premium" fuel

Listing all constraints may help suggestions.

Jes

[GarthW]

Yeah mats for sure your right there, i've just been looking in a Street Car magazine which was given to me whilst i was laid up in hospital, and never noticed the article they did on twin turbocharging a corvette, they lifted the whole chassis up and off the car and damn that driveline is massive...got me thinking though...

[cchan]

The original poster didn't specify, but I assume this is:
1. for a street car
2. needs to pass CA smog (at least the sniffer)
3. needs to run on lousy quality CA "premium" fuel

Listing all constraints may help suggestions.

Jes

Hi Jes,

You are correct on the above. Handles really well and stops on a dime. Eventhough the alfa is running strong now but I feel it is still alittle on the slow side for pick up. Not the 0 60 times but 60+. The BMW M5 feels that alot faster and the BMW M3 feels alittle faster. How do you like your racing Milano with the 3.7L? Do you have it tweaked for 425hp and your drive train is holding out? I am not sure what JJ's Race Car is doing but it appears he is still sorting the starter, etc. I am still waiting to see how these two projects turn out.

[cchan]

If I were you and money was not an issue I would leave your 24v GTV6 alone and find another GTV6 to build. I would do a 3.5 24v twin-turbo with front mounted Getrag 6 spd gearbox. This would take serious engineering and modification, so you would need to find someone willing to build for you. Don't expect a bolt-on. I'm considering doing something like that some day...
Jes

Hi Jess,

Your suggestion is valid since I learned from this project and JJ's suggestion to decide what you want (ie: street Car or Track car) before you start your project and then don't change midterm. Stay focused so you can finish your project. When I started my restoration I originally wanted 400 hp but I settled for less since I was thinking to get eveything sorted and running strong at 270hp. At the time, this seemed like a high goal given my starting point. Now that I am done, I was just thinking it cann't be that much more effort or $ to get to the original 400hp goal.

Of course $ is always an issue and if it takes another 20K to do this then I probably won't do it. If I did do another GTV6, I think I would go stock and try for a concourse Alfa. However, I think in the Alfa world it doesn't make sense financially to put $25-$50K in a GTV6. Hopefully one day the GTV6 will be this valuable but I don't think this will be anytime soon. Especially since it looks like a GTV6 is not too popular with Alfa Fans and I see that the Calloway did not sell for $25K which I think is a bargan. I see other GTV6's for sale at $3,500 to $10,000 and no one is buying them. Therefore, from the financial point of view, I should just keep the $ in the safe. If I do restore another Alfa, it probably should be an older model like a 67 GTV or older or even a Guila.

[ar4me]

My 3.7 still has not seen serious track time - been too busy with work, buying new house, keeping my current race car running, and get quality time with family. However, the 3.7 race car is currently in pieces as I'm doing some major changes to it, yes, drive line. I will be running a one piece carbon fiber driveshaft, a race front driveshaft coupling from Alex (Scuderia del Biscione), light weight clutch, lightened transmission with close ratio setup. My main motivation for the carbon fiber driveshaft is safety given the HP. Of course, removing mass benefits as well. It is coming together slowly - only got so much time... Maybe I'll get it together next year...

The Callaway is only recognized in the US. It is not considered an original Alfa in most parts of the world. Of course, recognition in the US may be sufficient for appreciation.

If your 24v GTV6 was my car, I would not start upgrading the engine. I think it will take a lot of $ to get to 400 HP if you want factory reliability, driveability, serviceability, pass smog (sniffer), run pump gas, etc. Not to mention the headaches you will likely face. Enjoy your 24v GTV6 as it is - it is a great car !!!

Jes

[GarthW]

Well cchan, as for the money it really shouldnt matter, as long as it doesnt send you broke though, but if your heart is in the right place, the money factor shouldnt come into it. I put just abit over $12k in getting my car boosted, would have been way more if i didnt do alot of the work myself, and to me there is no other car i'd rather put cash into, i only paid $5k for it nearly 9 nine years ago, and basically its the only hobby/interest i really have at the moment.

Some might say i'm crazy, but guys out there have paid alot more to have a modified N/A 24v under the bonnett and still could only dream about the torque my car produces, what their cars torque range is what mine can produce on very low boost, so to me it has been a worthy exercise. Alfas i love and will continue to do so. Mine will take another few years maybe to have it exactly as i want it, but i'm more than halfway there now...


But on this 400HP subject, the numbers should need not worry you, and they certainly wont once you have the power to weight, and great response. Alot of people out there are so concerned about dyno mumbers and what have you, if you boost the 24v the torque will be so crazy, the HP will be irrelevant. With the torque you reach freeway speeds+ in a short side street with no fuss, ok i would love the sound of a 3.7 24v, but at the end of the day, my little 2.5 will destroy it with light pressings of the throttle in every gear, fact and proven. If you can do alot of the work yourself, boost it and you wont be sorry...

[Greg Gordon]

I agree with everything Garth says.

Since the subject of supercharging, and my kit came up, I will chime in here. First of all my kit (with the MP62) can NOT deliver 400hp, at least I don't think it could do it efficiently. The 62 cubic inch supercharger just isn't big enough. It's sized really well for the 200-300 flywheel horsepower range, and in this range it's awesome.

The most powerful car running my kit has 291 rear wheel horsepower at 5500rpm and 313 torque at 2700. That's a 3.0 running "S" cams, slightly ported heads, a PWR intercooler, expensive engine management and IAP headers. I feel that represents the upper limit of what my kit can do.

To get 400 hp from a supercharged 12v Alfa 3.0 you would need either an MP90, a TVS 1320 (about 80c.i.) or bigger. There are various screw type blowers that could do it as well.

There are various centrifugal blowers that could do it. The centrifugal setup shown in this thread looks nice, especially with the custom manifolds. However, as I have often pointed out centrifugals just don't do much for overall power under the curve. They do give good top end power, but they do almost nothing for the bottom end, and not much in the mid range. It's very common for 350hp Roots/Screw/Turbo cars to out drag 400hp centrifugal cars.

As an example, I was recently doing some dyno work at a shop in Tulsa that specializes in the newer Ford V8s. On the dyno right before us was a Mustang 4.6 with a centrifugal blower and about 550 rwhp. The Milano with about 260 rwhp has more horsepower and torque below 3000 rpm than that Mustang.

Greg

[MD]

..practical as ever Greg !!

it's implied but for some it needs to be said.
Bottom end grunt is what you need for a street car end of story no matter how you choose to get there.

[GarthW]

Thats amazing Greg how the Milano was making more torque than the mustang, that i believe. Even with that HP, the power to weight of the Alfa and better low down torque would give that mustang a good run, nothing like great responsiveness and power to weight..

And yes MD, when she gives it down low, thats how we like it right!!??

On low boost mine was making 350nm at only 3000rpm with the standard fuel pump, and that was with a massive air leak we discovered later, also i used the standard factory rubber elbow air intake thingy which ballooned to the size of a football, literally. The low down torque was staggering. So it would have been closer to 400nm. Why was i running the standard pump...i simply ran out of cash... Same as why i didnt have a full aluminium air intake pipe as i have now...embarrasing it was, but hey i sunk everything i had to get it that far, for i'm single, no kids and i just love my car to bits.. So anyway that gives you guys an idea on what torque its going to produce once i finally sort out a new pump and give it 100% wide open throttle...ooh baby!!

Just hope i get her on the road before Alfesta next year, Alfas 100 year birtday bash.
Should start a thread about that actually on who's coming down to Melbourne for it....arrrgh i'm getting side tracked again...

The car running your kit Greg with nearly 300rwhp would be a hoot to drive, that is plenty in my book, thats nearly 100rwhp more than what a modified N/A 24v could produce. Very nice indeed.

[cchan]

What about the S.A. N.A engines with 425 hp at the crank. This must be at least 340HP at the crank (20% loss in drive train est). This is more than 300 HP so am I missing something?

Of course maybe I have my facts wrong and the Glenwood motors don't really produce this HP?

[GarthW]

Yeah would cost you around $20- $30k for an N/A engine to produce that.

You see thats the beauty of forced induction, you dont have to port, change the cams, things like that, your power adder is the supercharger or turbo. Forcing more air in is the way to go.

There's a guy here in Melbourne who paid that kind of money for his gtv6 to have that HP, and its only suited for the track, yeah its quick, but its very loud and its driveabilty would not suit the street...theres guys getting around in 9sec street cars and they comfortably cruise the streets no problem..damn theres guys with 800hp supras and they drive them daily...

[Mats]

What about the S.A. N.A engines with 425 hp at the crank. This must be at least 340HP at the crank (20% loss in drive train est). This is more than 300 HP so am I missing something?

Of course maybe I have my facts wrong and the Glenwood motors don't really produce this HP?

Have anyone actually seen this? In person I mean?

[GarthW]

No but would like too...

My mechanic here who has the IGNIS gtv6 has or had around abit over 300hp at the flywheel, thats roughly quoting for i dont know the true specs on it, but honestly if one of Glenwoods had over 420 at the crank, driving it on the street would not be practical, and like i said before, would cost you a fortune to have something like that built. Would be a track weapon and thats that.