Alfa Romeo Forum banner

1 - 20 of 24 Posts

·
Registered
Joined
·
93 Posts
Discussion Starter #1
The V6 appreciation thread has got me going ..... http://www.alfaowner.com/Forum/alfa-147-156-and-gt/322723-the-unexpected-156-v6-appreciation-thread.html

I'm looking at early ish 156's 2.5's as a project. I'd like to get over 200hp, is this possible without making it unusable on the road. I'v a lot to learn about the Brusso, so please bear with me on the stupid questions.

Would I be correct in thinking that all V6 156's are 2.5?
The reason I ask is that GTV's and 166 have a 3.0l with a few HP more?
Are engines and parts easily interchangeable and would I notice any difference?
Would a 166 swap be a good conversion?
Will GTA or 3.0L heads & cams fit and will there be any gains or is it all about cc's?
Any after market throttle body/ignition systems available?
Any reccomended tuners who do remaps/setups ?

I keep telling myself its gonna be cheapish project without spending thousands on trick bits and maching services. So please gents no £1000 airbox kits please. They will probably come at a later date :p
 

·
Registered
Joined
·
11,604 Posts
Dropping a 3.0 in has been done several times, try a search? :thumbs:
 

·
Registered
Joined
·
7,047 Posts
Yes the easiest will be to get a 3.0 and put it in the 156. The early 156 2.5 in my opinion is a nicer car to play with since the electronics are not as integrated.

If you want to stay with a 2.5 start with the following.
Since it’s a early 2.5 it will be fitted with the proper outlet branches.
Replace the inlet runners with the 45mm units from a 3.0 or 3.2 and match the base with them.
Do a proper service.
Improve the inlet track so that it can breathe a bit easier. K&N drop in filter, GTA inlet trumpet and replace the standard pipe between the MAF and Butterfly with a silicon and stainless pipe system.
Replace the exhaust with something that flows better and are proven.
Now you can replace the cams with GTA inlets or something a bit more aggressive if you want.
Difficult to say where the power will be by now but you would have gained enough to feel the difference.
 

·
Registered
Joined
·
377 Posts
Replace the inlet runners with the 45mm units from a 3.0 or 3.2 and match the base with them.
Improve the inlet track so that it can breathe a bit easier. K&N drop in filter, GTA inlet trumpet and replace the standard pipe between the MAF and Butterfly with a silicon and stainless pipe system.
Replace the exhaust with something that flows better and are proven.
Now you can replace the cams with GTA inlets or something a bit more aggressive if you want.
Had all above mods, and can confirm that car runs much better, but proper ECU remap is a must to unleash the full potential of this mods.....
 

·
Registered
Joined
·
374 Posts
Don't the 2.5's come with smaller more restrictive runner's than on the 3.x motors if so that would probably be a good cheep upgrade ?
 

·
Registered
Joined
·
7,047 Posts
Yes they do and replacing them with the 3.0 or 3.2 runners help. i think i did mention it in my first post.
 

·
Registered
Joined
·
7,047 Posts
Even without a remap there’s a nice improvement. In SA we do not have the luxury of getting a remap so I can confirm that all the changes will give a nice and reliable increase without a remap.
But a remap will definitely release even more power.
 

·
Registered
Joined
·
45 Posts
Hey turbonutters, is there recorded 3l conversions in SA
Seems difficult to pic up a 166 engine for cheap
And what about a piggyback?
 

·
Registered
Joined
·
7,047 Posts
Yes but the most common is to change the 2.5 to a 2.8 by fitting 3.0 liner’s and pistons.
Unfortunately that involves a lot of machining.
A piggy back help’s but a proper remap is the best when available.
 

·
Registered
Joined
·
142 Posts
Doesn't changing to bigger inlet runners without remap give less low end power and drivability that's what was mentioned when I asked same question.
 

·
Registered
Joined
·
7,047 Posts
No it improves all over.
We have done it on a lot of 2.5’s and it work’s brilliantly.
We even upgraded a old 155 2.5 by fitting 156 2.5 runner’s.
 

·
Registered
Joined
·
142 Posts
Howuch extra power are you likely to achieve I have a decat exhaust with straight thru backbox, a Cda enclosed filter with cold feed pipe plus silicone throttle body hoses?
 

·
Registered
Joined
·
7,047 Posts
It’s difficult to put a value to it since we haven’t done a back to back dyno but its enough that you can notice a difference especially in response. Hp wise probably not enough to offset the cost if you have to buy new runners.
You will probably gain by ditching the cda and putting a oe air box with BMC or K&N replacement filter and GTA intake on it as well.
That’s one thing that’s proven a CDA can not flow as much air as an optimized OE air box unless you drive a 147 2.0 or smaller.
 

·
Registered
Joined
·
142 Posts
If I can find a cheap set second hand must worth a try what's the difference to the gta intake to the custom I have made is the hoses bigger?
 

·
Registered
Joined
·
7,047 Posts
Show me a picture of your setup.
The main thing with the GTA mod is the trumpet in front of the air cleaner (cold air induction) is larger than the 2.0 and 2.5’s.
The air boxes on all 156’s are the same size.
 

·
Registered
Joined
·
142 Posts
Hi turbonutters can't upload pic of the intake using an iPhone but could probably email it to you if you have an address?
 
1 - 20 of 24 Posts
Top