A little more power for an 86' GTV6

[hmd]

difference between 106 and 115 could just be in the dyno runs, even on same day you can have 5-10bhp differences in how you tie the car down and tyre pressure etc...

Just quietly i think Beninca's know what they are doing

Yep, but Sheldon said his 115 was a few year ago.

[John Toomath]

difference between 106 and 115 could just be in the dyno runs, even on same day you can have 5-10bhp differences in how you tie the car down and tyre pressure etc...

I'm sure for the purposes of this particular thread, two consistent observations make a fact.  At the dyno day 2 years ago my 2.5 recorded 126hp, yesterday 127hp, so I conclude that Beninca's dyno run technique produces reliable results. 

What I did observe was that a number of cars need a bit of a thrash before they turn up for the run, as under load some cars would not spark cleanly and stumbled towards the top end, often accompanied by a carbon cloud.

[Paul Gulliver]

Yep, but Sheldon said his 115 was a few year ago.

Rest assumed that Sheldon's car usage in the intervening years didn't exactly fall in the "driven by a a little old lady on Sundays category".  It may have been driven on Sundays but most likely At Philip Island , Winton & Sandown. As Sheldon said it was "tired", maybe these Sunday outings made it " more tired".

[Sheldon McIntosh]

106 is pretty averageshit for a 2.5.  I got 115 out of my tired one a few years ago, John Toomath did about 125 in his standard one today, that has a nice exhaust system though.

difference between 106 and 115 could just be in the dyno runs, even on same day you can have 5-10bhp differences in how you tie the car down and tyre pressure etc...

That's true, but John's result certainly shows there is some consistency with the Beninca dyno over different days.  I was also comparing it to some of the other results on the day.  For example it was 12bhp and 25Nm behind a standard Twinspark, which is not very good at all, and is certainly down to more than just external factors.

Sounds like it may be a pretty tired engine, it might not be worth spending any meaningful money on it?  Is it smokey? 

I didn't know you were there Sir Lancelot, I would have introduced myself.

[Paul Gulliver]

Just quietly i think Beninca's know what they are doing

That's true, but John's result certainly shows there is some consistency with the Beninca dyno over different days.  I was also comparing it to some of the other results on the day.  For example it was 12bhp and 25Nm behind a standard Twinspark, which is not very good at all, and is certainly down to more than just external factors.

Interesting point Sheldon and a suppose it begs the question what was your expectation of your car on the day. ( bragging rights ,or  give the car a kick and put it back in the garage.

I couldn't make it yesterday but my Alfetta Twin Spark GTV made 110 rwhp at last years dyno day. I have been back to Beninca's  in the last month or so and with a starting point of 110 rwhp . (exact same figure as 12 months earlier) and they have got the car back to 120rwhp. Where was the improvement ?

1. The nuff nuff owner (me) had retrimmed / carpeted the car and didn't set the throttle bump stop on the floor correctly so i wasn't getting full throttle ( + 5 hp)
2. A fiddle with the AFM  (+ 5hp)
3. They also noted that the engine could reach full horsepower but it fell away pretty quickly when the engine got hot. So some Beninca improvements to the 30 year old radaditor and i'm reasonably sure that i'm getting a reliable 120 rwhp at the track.

As i mentioned earlier Beninca's really do know their stuff and a few hours of dyno tuning is money well spent. It is therfore little wonder that club luminaries like Alan Goodall & Jim Neilson car's have spent time a fair ammount of time on Beninca's Dyno.

[MD]

Could somebody please pursuade the Beninca workshop to move to Brisbane for a short 5 year stint ? Guaranteed tax break incentives provided..

[L4OMEO]

Could somebody please pursuade the Beninca workshop to move to Brisbane for a short 5 year stint ? Guaranteed tax break incentives provided..

+1

[Sheldon McIntosh]

a starting point of 110 rwhp . (exact same figure as 12 months earlier) and they have got the car back to 120rwhp. Where was the improvement ?

Dammit Paul.  Stop finding power, we were pretty close in terms of speed.

Just as well I'm putting in the 3 litre I suppose.....

Nearly ready.

[Sheldon McIntosh]

Thought I might update my experiences of the 3 litre since I put it in, just in case Sir Lancelot is still considering the upgrade.

I got the engine very, very cheap, and I was 99.9% certain that it ran well, and I knew that the belts and water pump were renewed 6 months previously.  I probably spent about $1000 on getting it in, but that included buying an engine crane and lots of shiny new tools, and a new centre bearing.  It's my first engine transplant so I went through it all slowly and methodically, because I was lifting and installing the engine on my own, and it's hard enough doing it once that I REALLY didn't want to have to lift it again.  I'm not too handy with the tools, but I managed to get the thing in and started, so it's not too hard a job.  I'm running the standard L-Jetronic from the 90 in it for now.

The first decent jab of the throttle on it's first run and I was already convinced that every 75, 90 and GTV6 should be like this.  It's a very, very nice engine, and the mid-range is just sooooo much better than the 2.5.  Mid-range is what you feel the most on the road, so the 3-litre really is the way to go.  It doesn't have quite the rush at the top end that you get used to with the 2.5, but that's because you're already going a lot quicker thanks to the much bigger mid-range. I will definitely be putting a 3 litre into my road 90 when I get the opportunity, and I would highly recommend it over doing any serious mods to a 2.5.

The sound is definitely different to the 2.5, but if anything I prefer the sound of the 3.0  It sounds like a bigger, angrier version of the 2.5 at low and mid-range engine speeds.  It doesn't scream quite like the 2.5 at the top end, unfortunately.

One caveat though, I've only driven the 3-litre in my 90 (and a 164, but that's not really relevant here when we're talking about the lighter cars), which has a stripped out interior with no sound deadening, and it's sitting on some polyurethane engine mounts, so every noise and vibration is amplified, and it's lighter than a road car (but not to a huge degree).

[Jekyll and Hyde]

The first decent jab of the throttle on it's first run and I was already convinced that every 75, 90 and GTV6 should be like this.  It's a very, very nice engine, and the mid-range is just sooooo much better than the 2.5.  Mid-range is what you feel the most on the road, so the 3-litre really is the way to go.  It doesn't have quite the rush at the top end that you get used to with the 2.5, but that's because you're already going a lot quicker thanks to the much bigger mid-range. I will definitely be putting a 3 litre into my road 90 when I get the opportunity, and I would highly recommend it over doing any serious mods to a 2.5.

One caveat though, I've only driven the 3-litre in my 90 (and a 164, but that's not really relevant here when we're talking about the lighter cars), which has a stripped out interior with no sound deadening, and it's sitting on some polyurethane engine mounts, so every noise and vibration is amplified, and it's lighter than a road car (but not to a huge degree).

Rest assured that the feeling of monstrous torque increases over the 2.5 is still there in a full trim road car (right Simmo?).  100% agree that every GTV6 should have come with the 3 litre.  Not so sure about the 90's getting it though 

[Simon Aarons]

Rest assured that the feeling of monstrous torque increases over the 2.5 is still there in a full trim road car (right Simmo?).

Yeeeesssssss!!!!!!

[Sir Lancelot]

Sheldon - Thanks very much for the description, i'm a little more inspired, and would definitely love the chance to do the transplant myself. At this stage its a matter of setting aside the time and money, so the project is on hold. When the time comes, i'll seek out your expertise    In the meantime, i'll research what i need and what it takes. I think the biggest unknown for me is exactly what comes from the 3L, what is retained from the 2.5L and what requires serious modification, if anything.

[Sheldon McIntosh]

Happy to help.  There were numerous bits of information I gleaned from various sources on the web which were very helpful, and there're plenty of people in the club and on this forum who have done the same thing and can point you in the right direction.  As I said, if I can get it done (albeit very slowly), anyone can.

The way I did it, keeping the 2.5 plenum and injectors etc, no serious modifications are needed.  It's a bit more involved if you want to keep the 3 litre stuff.  I didn't bother because I'll probably go to a megasquirt or similar eventually.

This link  http://www.alfamilano.com/verde_rebuild/finishingup.htm  will give you some idea of what's involved.

[martym00se72]

Hi,
I have been reading this thread over time - started interesting, digressed to total (but entertaining) BS and has become interesting again...

I want to pose a question - we all want the power & torque of a 3.0 but the sound of a 2.5 right? What are people's thoughts, pro's/con's of going supercharged 2.5 vs NA 3.0? Of course you could go for supercharged 3.0, but if figure the next step from a NA 2.5 is either the 3.0 of to strap on a supercharger for probably around the same number of shekels. My way of thinking is the supercharger - gives power, keeps the sound...
Cheers
Marty

[MD]

The difference between the sound of these engines is both overstated and negligible.

If the plan is to improve performance of the 2.5 by supercharging simply on the basis of engine noises, do not leave out the perceived benefits by ignoring how muich of a pain in the rear all the charger whine is going to impose.(for a street car).

Follow the KISS rule. Strap in a 3 litre. Save bucks and complexity. Keep the true engine noise only by fitting an appropriate exhaust system and open up the intakes. You'll soon be basking in V6 glory.

If you want to improve on the 3 litre, import the 2 litre V6 and strap on twin turbos, take it to 10,000 rpm and measure the grin in feet and not in inches.