[Jamhot77]

Is there a sensible reason why you would convert your engine to 3.8 for between 8-10k rather than add a supercharger for 5k to the standard 3.2?

The supercharger gives either 320 or 340 bhp and the conversion is just over 300 bhp.

I have got my GTA to a good state and the next thing I will be looking at is to increase the power a bit. It has already has a basic remap by Angel tuning and that is meant to add approx 16BHP with CDA. Recently added the awesome wizard exhaust and would like the car to go a bit quicker like it sounds.

What are peoples opinions?

 

[Joss]

Is that autdelta's price by any chance? I don't think autolusso charge that price

 

[Jamhot77]

Is that autdelta's price by any chance? I don't think autolusso charge that price

8-10k was taken during convo with Ned about the 'FULL' autolusso engine rebuilt with all the extras. I dont know what they start at to be honest.

 

[Guest]

Is there a sensible reason why you would convert your engine to 3.8 for between 8-10k rather than add a supercharger for 5k to the standard 3.2?

The supercharger gives either 320 or 340 bhp and the conversion is just over 300 bhp.

I have got my GTA to a good state and the next thing I will be looking at is to increase the power a bit. It has already has a basic remap by Angel tuning and that is meant to add approx 16BHP with CDA. Recently added the awesome wizard exhaust and would like the car to go a bit quicker like it sounds.

What are peoples opinions?

Yes there is actually at least one very sensible reason.. If your engine has done more then 35.000 miles, then no Tuner in their right mind would or should fit a S/C less a rebuild of the engine is part of the job.

brgds
peter

 

[Jamhot77]

Yes there is actually at least one very sensible reason.. If your engine has done more then 35.000 miles, then no Tuner in their right mind would or should fit a S/C less a rebuild of the engine is part of the job.

brgds
peter

Rebuilt this year!

 

[Guest]

Then all stations should be green for a S/C coversion! Enjoy!

 

[Guest]

Depends what you want out of the car. The 3.8 gives you huge slugs of torque but not much extra bhp (think 280 - 300 max). The 3.8 needs work on its breathing to release more power at the top end but the thing I like about it is that the power you get is usable in everyday driving. Peak torque is now 290 ft/lb and peak torque and bhp come in about 1000 rpm earlier than on the 3.2.

I would compare that to the power delivery of an s/c conversion and see what you think makes sense for what you want out of the car compared to the cost. I've not driven any s/c cars so can't really comment on how they drive.

Ned always discouraged me from a 3.8 conversion because of the cost relative to the "return", I only had it done because I needed an engine rebuild. But I do love it!

Of course you could always do both

Cheers,

Nigel

 

[Guest]

Rebuilt this year!

So you have GTANigel's opinion. Try messaging an AOer with the username C8BUK. He has a 156 GTA 3.2 Supercharged. He may give you the other side of the coin. He's a thoroughly decent chap, I'm sure he'd be happy to chat about it.

 

[Captain Slow]

A supercharged 3.8, now that would be impressive!

 

[LJ_GQV]

Isn't there a supercharged 3.7 147 GTA? pablos i think

 

[Autolusso]

Isn't there a supercharged 3.7 147 GTA? pablos i think

When it is running (3 days in 3 years :tut

Ned

 

[Autolusso]

Is there a sensible reason why you would convert your engine to 3.8 for between 8-10k rather than add a supercharger for 5k to the standard 3.2?

The supercharger gives either 320 or 340 bhp and the conversion is just over 300 bhp.

I have got my GTA to a good state and the next thing I will be looking at is to increase the power a bit. It has already has a basic remap by Angel tuning and that is meant to add approx 16BHP with CDA. Recently added the awesome wizard exhaust and would like the car to go a bit quicker like it sounds.

What are peoples opinions?

James stop it you have spent enough money this year!!!!!

Ned

 

[Joss]

8-10k was taken during convo with Ned about the 'FULL' autolusso engine rebuilt with all the extras. I dont know what they start at to be honest.

Ah fair enough then:thumbs:

Yes there is actually at least one very sensible reason.. If your engine has done more then 35.000 miles, then no Tuner in their right mind would or should fit a S/C less a rebuild of the engine is part of the job.

brgds
peter

See it's comments like this that prove that some people are just ignorant. Just because an engine is high mileage doesn't mean you can't tune it. My 156 JTD on 160,000 and my 155 ts on 220,000 miles proves that. I suppose you think that all cars explode at a 100,000 miles too Oh no I better rebuild the my GTA before I blow it up as it's done 110,000 miles now......... Yes you should upgrade components like low comp pistons, big end bolts etc so you can run boost

 

[Guest]

I've met up with the guy (Colin IIRC) running the ex-Autodelta 3.7 SC 156 GTA that was sold through Buzz Alfa. He's pretty impressed with that. You can hear the supercharger coming......

 

[AYAT]

i thought that was just supercharged. there was the hideous looking 3.7 supercharged autodelta gt going for around 13k that would have been worth it for the engine.

 

[Guest]

i thought that was just supercharged. there was the hideous looking 3.7 supercharged autodelta gt going for around 13k that would have been worth it for the engine.

Oops you're right Ayat, must be old age. I was labouring under a delusion there even though we've had loads of threads about that car.

Cheers,

Nigel

 

[stooge166]

The increase in capacity of the engine of around 18 - 19% will give you a corresponding increase in power up to 5000rpm, after which the returns fade due to the air flow capcity of the plenum and head.

The centrifugal supercharger will give almost no boost at low revs, starting to give 20 bhp or so extra at around 4000 rpm, and then giving a good increase in power right the way to the redline. Mind you, if selcuks threads are to be believed (I have no reason to doubt one way or the other) then you can get similar returns up to 6000 rpm from just modifying the plenum, exhaust manifolds and, to some extent, the throttle. This would suggest that the supercharger on a standard engine is doing little more up to 6000 rpm than overcoming the restriction of the undersized plenum. This is hard to believe of course, but read the threads and examine all the dynographs before you dismiss this point entirely.

The question naturally arises as to the benefits of a centrifugal charger when fitted in addition to the above plenum and exhaust changes; I have yet to find any information on such a car.

There is however, quite a lot written about 3.8 bussos with modified plenums, and these do seem to have somewhat better performance at the top end than the standard plenum 3.8 engines, but not so much as you might expect, expecially when you still have the limitations of the standard cylinder head internals.

All of the above is based on too much reading of the internet and next to zero empirical knowledge.

 

[GhostyDog]

Depends what you want out of the car. The 3.8 gives you huge slugs of torque but not much extra bhp (think 280 - 300 max). The 3.8 needs work on its breathing to release more power at the top end but the thing I like about it is that the power you get is usable in everyday driving. Peak torque is now 290 ft/lb and peak torque and bhp come in about 1000 rpm earlier than on the 3.2.

I would compare that to the power delivery of an s/c conversion and see what you think makes sense for what you want out of the car compared to the cost. I've not driven any s/c cars so can't really comment on how they drive.

Ned always discouraged me from a 3.8 conversion because of the cost relative to the "return", I only had it done because I needed an engine rebuild. But I do love it!

Of course you could always do both

Cheers,

Nigel

The supercharged 3.2 I drove had a very linear power delivery all the way ton the red line it felt consistently powerful when you put you foot down pretty much wherever you were in the rev range. It s very noisy though and the pipework deforms the standard GTA bumper on a 147

Making friends again Peter?

Nice collection of cars your getting, whats that one in your avatar?

 

[Guest]

Peter, might I ask how many 3.7 conversion have you done and what are the results ?
I am quite curious, as most conversions I've seen offer a very small power increase.

 

[Pud237]

I think forced induction is something that should be considered if your goal is maximum power rather than more power and retaining the characteristics of a normally aspiratd Alfa V6. But I think bolting it on to an engine which is 10.5:1 compression ratio is not a good idea. It restricts the amount of boost you can safely use becaus of heat, detonation, total cylinder compression etc. In my opinion a better idea would be to open the engine up and replace just the pistons and connecting rods for forged lower compression ones. This should be a bit cheaper than a 3.8 kit and you also don't have to pay for the machining costs for the block, the heads, the liners etc. Obviously you still have to buy a supercharger and mounting brackets though, but with lower compression you can safely run a lot more boost. You would end up with much more power than a 3.8 for similar overall cost, and it would be a safer option than bolting on a supercharger to an engine that is designed to be normally aspirated. The downside would be that it sounds and feels like a supercharged car (if thats a downside for you).

Alternative would be to use a turbo rather than a supercharger.