A little more power for an 86' GTV6

[Sir Lancelot]

Hey all, it's been some time since I've been on the forum. There have been times lately where I would definitely like a little more power in the engine, and a couple of mates have upgraded to 3.0 12v and 3.0 24v engines, and won't shut up about it! Sounds great.

Basically my car is standard with the exception of upgraded suspension (thicker torsion bar, yellow konis). As such, I've been very content to leave it standard, I quite like it that way. In part, I'd like to do something to the motor to get more out of it, on the other hand, perhaps i should be maintaining the car as original as possible?!?! Anyway, i guess that's for me to decide.

So, how practical are the following options, and does anyone have an idea of cost?

- 2.5L, different cams
- 2.5L, extractors
- 3.0L 12v
- Any other ideas?

I've left out the 24v 3.0L for now since i know it's quite expensive, particularly a new computer. I'm also under the impression modding the 2.5L will really only benefit higher rpm - is this correct?

I think a major question is - should i get to work on the 2.5L 12v, or get the 3.0 12v and then improve that? Also this is predominantly my road car, with minimal track use at the moment.

[BradGTV]

for best power and value for money:
http://www.hiperformancestore.com/superchargerkit.htm

[dehne]

get the 2.5 chipped my one is auto delta chiped and have had it up to 250kph but if you call monza they can tell you who to use to chip it i think they are called powerchip good performance for less money

[dehne]

a nice long straight road in central vic no cops for days i may have had a tuned exhaust under it to, but not sure if i had removed it due to epa regs was at 110db's a little to loud for todays standards

[Sheldon McIntosh]

get the 2.5 chipped my one is auto delta chiped and have had it up to 250kph but if you call monza they can tell you who to use to chip it i think they are called powerchip good performance for less money

250 km/h.  From a chip and an exhaust. 

[Sheldon McIntosh]

Sir Lancelot, the 2.5 is a lovely engine, and sounds better than the 3.0.  I wouldn't bother spending too much money on it though, when you can get a 3 litre for around $1000. 

But if you did want to keep the 2.5, maybe go for a set of Vin's extractors, they're an extra 9bhp, then you could play with a bigger AFM, like the BMW mod which is pretty common.  Maybe 20bhp all up there, and around $1200 and lots of time.

A 3 litre (12v) should be an extra 30 bhp, as well as loads more torque, and can be made to look exactly the same as your 2.5, so at least keeping the appearance original.  Then you can do the same mods as above, for another 20bhp or so. 

50bhp is nice, but you'd still be about 50bhp behind dehne and his amazing chipped 90 which can do 250km/h. 

[Paul Gulliver]

250 km/h.  From a chip and an exhaust

Sheldon , You forgot the 25 Y.O wildly optimistic Alfa speedo

[Brad M]

All entrants must arrive by 8:30 AM to check in and prepare their cars. Scrutineering of cars in will take place between 8:45 AM and 9:30 AM.

8:30	ENTRANT SIGN IN – DOCUMENT CHECK
9:30	OFFICIALS BRIEFING & DRIVERS BRIEFING (Attendance is compulsory)
10:00	MIN 4, 8 X TIMED TESTS CONDUCTED.
16:30	VENUE VACATED

Hope you can fit this into your day.

[Neil Choi]

Hey Brad,

That's a bit rude to hijack this thread!!!!!!!

Neil

[Davidm1600]

I actually suspect he was just a little lost !!   unless he has an ulterior motive, which isn't quite obvious.

Gully I can well imagine you are dead right there re the 25 yo over optimistic alfa speedo, that is unless the blue stripe and bright yellow paint can account for some extra gee gees 

[dehne]

other than its a black stripe, and its not that car either please do remember that a standard 90 is good for 220-230 anyway a little mod is only gaining 20 more kpm so its not that disbelievable that this can happen and my speedo is only 4km out as have tested at 60,80,100,and 120 and its consistant

[Brad M]

All entrants must arrive by 8:30 AM ... Hope you can fit this into your day.

I was wondering where that went

I actually suspect he was just a little lost !!

Yeah I was

Gully I can well imagine you are dead right there re the 25 yo over optimistic alfa speedo

Accuracy didn't get better in the next 20 years ... my 147 says nearly 110, yet the Tom Tom says 100.

[Sheldon McIntosh]

please do remember that a standard 90 is good for 220-230 anyway

No it isn't.  Please show us your evidence for this.  All the tests I've seen say that just over 200km/h is top speed, 205km/h being the highest I've ever seen quoted.  And I've published most of these in the Cross & Serpent.

a little mod is only gaining 20 more kpm

Assuming your 230 km/h was correct, it would take a lot of horsepower to go from 230 to 250 km/h, not just a 'little mod'.  To go from 205km/h to 250km/h would take at least 100bhp at a guess.

But, prove to me that a standard 90 can do 230km/h and I may be more inclined to believe the rest of your claims.

[Neil Choi]

Interestingly (which is a bit off topic),

A 156 GTA has a reported top speed of 241km/h and that's a tad under 250 bhp.

An Alfa 90 has 154 bhp and top speed of 203 km/h.

An Alfetta GTV 2L has 122 bhp and a reported top speed of 190 km/h.  Pretty tough to see 190 km/h, try as I may, most is about 180 km/h in good conditions.

So 100 odd bhp needed to get 50 km/h more on a comparative basis.

So to get more towards top speed, it almost becomes inversely proportional with power ie a few km/h more requires a huge amount more power.

This is not taking into account weight, of course.

Make sense and true or have I over-analysed.

[aggie57]

For everyday use it's not absolute power you're wanting but mid-range power and torque.  For that a set of Vin's extractors will help, you'll get an even crisper exhaust note and they can be moved to a 12v 3.0 later on with the same benefits.

Something else worth considering is opening up the intake runners and cleaning up the bottom of the plenum.  In the early days of V6's one of our well known club members did that with excellent results.   Likewise if you are fitting extractors take the time to make sure that it is bolted up clean and the ports are well matched.