12-18-2007, 06:16 AM
|
 |
Registered User
|
|
Join Date: Oct 2007
Location: Wokingham , Berkshire, UK
Posts: 11
|
|
|
OK no turbo then. 2litre ts to 200 bhp NA?
OK after reading and searching to make sure this hasnt been covered specifically, i want to find out how to get 200 bhp out of my 2 litre twin spark LE. most engine performance upgrades on the site relate to the 3 litre which is all well and good for those with the nicer sounding car but i only have teh better weight distributioned one! 
it is currently standard with rear cat removed.
User Max Banks has got "198bhp" out of his webber carbed twin spark engine. so i think this should be even easier as i and others have fuel ignition?
i also have a couple of autodelta cams which i intend to fit
so guys what do i need to do?
PS i want to keep it naturally aspirated and relitively reliable. i dont wanna get much more than 200bhp so lets keep it all sensible and to minimum work requirements! |
12-18-2007, 06:41 AM
|
 |
Registered User
|
|
Join Date: Aug 2003
Location: 58 Deg. North
Posts: 1,898
|
|
|
Not to shoot you down or anything but 200Hp from a Twinspark involves a lot of work, to mate it to "PS i want to keep it naturally aspirated and relitively reliable. i dont wanna get much more than 200bhp so lets keep it all sensible and to minimum work requirements!" would be impossible.
Sorry.
__________________
Mats Strandberg
GTV 2000 -77 Pics <= These are picture links you know...
75 Turbo -87 *sold* Pics <=
|
12-18-2007, 12:31 PM
|
|
Registered User
|
|
Join Date: Dec 2006
Location: The Netherlands
Posts: 99
|
|
|
Buy the book: the alfa romeo DOHC engine high-performance manual by jim Kartalamakis...
ISBN 1845840194
|
12-18-2007, 07:17 PM
|
|
Registered User
|
|
Join Date: Jul 2007
Location: Brisbane Australia
Posts: 34
|
|
|
Mate, if you want to make you twinnie go faster, get some weight out of it. These engines are fantastic, reliable little units that pump out almost 150hp in good tune and without a cat. You can boost the ponies slightly by upgrading your exhaust and getting some more direct cold air flow coming into the airbox. Upgrade your secondary pipes to 1 3/4 inch and your main pipe to 2 1/4 inch, install a high flow cat to keep the coppers happy and opt for a good quality straight through muffler. You may need a resonator in the middle to meet local noise restrictions. A K&N or similar air filter will also make a minor difference.
The rest of it is weight saving and firming up the suspension a little. If you do that you'll certainly give a 3 litre a good run around a tight mountain road - you just have to wave goodbye to them on the straights.
Put your twinnie on a diet, sacrifice some creature comforts, such as sound deadening, stereos and air-con, and watch him go!
Cheers.
|
12-19-2007, 12:27 AM
|
|
Registered User
|
|
Join Date: Oct 2007
Location: Wokingham , Berkshire, UK
Posts: 11
|
|
|
damn, i know i could save loads of weight stripping it but it is nice to listen to the aftermarket stereo, and only the engine when givin it large, i also need the spare tyre as i tend to chunk mine as i induce lift off oversteer before i tame the drift!
already got eiback springs and koni shocks, need a tortion bar at the front tho could also do with getting rid of massive free travel before the brake pads make contact with the discs! i must go through 1/3 of pedal travel before i notice the brakes doing anything and i get some feel to the pedal.
but i am loving the extreem cold as it has mad the car spin up so easily from standing on dry roads, cant do it in summer! so i thought just a few extra brake would make it awesome all year round.
will go ahead with jims book and get the cams in. however if it doesnt do it for me then i will have to resort to the 200sx motor. (or just talk to max banks)
cheers for the response. ;-)
|
12-19-2007, 01:20 AM
|
 |
Registered User
|
|
Join Date: Apr 2007
Location: ipswich, uk
Posts: 282
|
|
|
200 brake is feasable N/A, but don't expect it to be cheap, nor particularly reliable if your going to thrash it everywhere!
Gavin Dacks got a 2ltr t/s running throttle bodies etc thats around 200bhp! Hes also in the UK
__________________
Spence
75 3.0 24v
|
12-19-2007, 01:53 AM
|
|
Registered User
|
|
Join Date: May 2007
Location: Brisbane
Posts: 165
|
|
 Quote:
Originally Posted by benjo1
User Max Banks has got "198bhp" out of his webber carbed twin spark engine. so i think this should be even easier as i and others have fuel ignition?
|
You do realise that Big Webers work better than the factory injection manifold?
__________________
1966 Giulia Sprint GT Veloce
1971 Ford XY GTHO (replica) race car (For sale?)
1982 Suzuki "Bathurst" Katana
1985 Suzuki RG500
1995 Cagiva Mito (race kitted 250 powered)
|
12-19-2007, 08:35 AM
|
|
Registered User
|
|
Join Date: Sep 2005
Posts: 98
|
|
|
even if the guy will struggle to get 200bhp all you guys that have mods to twinnies what have you done and what results did you get as we are about to d the same on our other 75
|
12-19-2007, 09:56 AM
|
|
Registered User
|
|
Join Date: Nov 2002
Location: SF Gay Area
Posts: 1,642
|
|
200 bhp is what race cars have. 230 bhp is almost the max with no VVT.
I think you would be happier with 170 bhp as it sounds like you are on a budget. How about these:
Ported and shaved heads (make sure the machinist knows what he is doing, maybe someone like Guy Croft  )
Cams
Exhaust
Custom chip reprogramming after all the above mods
__________________
1987 75 1.6ie
Mods so far: 185/65/14 Nankang HR Tires
|
12-20-2007, 06:21 AM
|
|
Registered User
|
|
Join Date: Oct 2007
Location: Wokingham , Berkshire, UK
Posts: 11
|
|
Quote:
alfaspence
200 brake is feasable N/A, but don't expect it to be cheap, nor particularly reliable if your going to thrash it everywhere!
Gavin Dacks got a 2ltr t/s running throttle bodies etc thats around 200bhp! Hes also in the UK
|
Quote:
alfaholic75
even if the guy will struggle to get 200bhp all you guys that have mods to twinnies what have you done and what results did you get as we are about to d the same on our other 75
|
agreed, why is it so difficult for people to share what they know, even if it cost an arm and a leg?
75evo
thank you thank you! is it easier to kick the vvt into touch then? anyway i will do what you suggest and then ask later if i want morealso i could quite happily spend a couple of grand on it seeing as it was a free be!
Quote:
la_strega_nera
I assume you mean injection.
You do realise that Big Webers work better than the factory injection manifold?
|
thanks i didnt know this! i thought injection was better as all cars now are, i guess due to the emission laws
thank you for some actual useful info and rarely seen from this forum since i have used it - positivity even at its minimum!
i belong to a 400cc motorcycle forum and no matter what you say you will be told the actual posibilities even if they are no where neer what you want and how to go about achieving them!
i know alot of people will be completely off their rocker in what they come out with but lets not all be grumpy old sods and let us inspire people!
also can you chip any ecu or would some Ve Hicles need an entirely new engine management system?
|
12-20-2007, 07:42 AM
|
|
Registered User
|
|
Join Date: Oct 2005
Posts: 300
|
|
|
I think the top for a highly developed race twinspark is in the 250hp range. Jon Norman and Dino Cresintini built GT3 cars for SCCA in the 90's for that.
The hp cut off changes if you are trying to use pump gas though. If you are using pump gas, programmable fuel injection and programmable ignition I would think the way to get 200+hp would be to concentrate on obtaining very high RPM with maybe 11.5 to 1 compression. Titanium rods will drop the rotating mass by 50% over the stock rods. Cosworth already makes a nice light race piston designed for the GT3 cars, so you could ask them to drop the compression a bit and concentrate on lightness. 5 main crank oiling and a high volumn oil pump would be a must. We have a set of billet aluminum main caps and integrated billet aluminum girdle to help keep the crank straight while spinning at 8000rpm and Jim Steck make a fine set of stainless headers. The cam and injection for this set up would be somewhat uncharted waters though as well as valve size and head work. The challange being making it so it has a flatter torque curve through the rev range to make it more driveable. I am guessing this is going to cost well over $10K before you are done but will still be a pretty reliable motor after it is sorted.
In stock form the twinspark makes a wonderful power curve. Why not just strap a 30hp nitrous w/fuel injection system in for about $1000? I don't think any motor modifications would be needed at this low level of boost and I think the bottles will actually last for a decent amount of time. The system could be manually armed but then set to automatically spray at some throttle setting.
My .02
Andy
|
12-20-2007, 09:20 AM
|
 |
In the Spiders' nest...
|
|
Join Date: Jun 2005
Location: Nutley/NJ & Middletown/OH, USA
Posts: 4,627
|
|
Quote:
Originally Posted by benjo1
....
Quote:
Quote:
la_strega_nera
I assume you mean injection.
You do realise that Big Webers work better than the factory injection manifold?
|
thank you for some actual useful info and rarely seen from this forum since i have used it - positivity even at its minimum!
i belong to a 400cc motorcycle forum and no matter what you say you will be told the actual posibilities even if they are no where neer what you want and how to go about achieving them!
i know alot of people will be completely off their rocker in what they come out with but lets not all be grumpy old sods and let us inspire people!
also can you chip any ecu or would some Ve Hicles need an entirely new engine management system?
|
The later generation of more modern systems not only use fuel injectors to feed fuel into the combustion chamber, but the release of fuel is controlled by electronic units which can be programmed to determine exactly how to act and react, across the entire RPM power band. It allows one to zero in on every specific point of the power band and program the amount of fuel to be delivered at each specific point. It follows this program and constantly adjusts the mixture based on the sensors that feed it constant information. The driver doesn’t have to do anything except press and release the accelerator, and the system reacts immediately to provide the fuel mixture (and power) that it was programmed to deliver. This level of control not only yields efficiency, but it also allows tuning that is impossible with a set of carburetors.
Of course, it took many years to get to this level of sophistication. A carburetor is a purely mechanical device. The SPICA (Alfa’s first answer to meet emission levels in the U.S.A. from 1969 until 1981), while much more sophisticated than a carburetor, is still a mechanical device. The first generation of electronic fuel injection systems, like the Bosch L-Jet, use sensors and electronic signals to control fuel mixture. This allows better control of the fuel delivery, and works better than a mechanical device, but they still don’t really have any “intelligence”. There is no program that the unit uses to determine the amount of fuel to deliver. It simply bases its decisions on the sensors, and its electronic set-up. The Bosch Motronic is the first system where some instructions are used to determine the amount of fuel to be delivered. That’s why one can change its chip, and hence alter parameters, to deliver more fuel and produce a more powerful explosion inside the combustion chamber. The amount of “programming” that can be achieved with the Motronic system is truly very limited, which is why there isn’t much choice beyond what is in an aftermarket chip. By comparison, a system that allows instructions at every point in the RPM range truly allows full control.
Another factor that is important to understand is that systems of the 1980s and 1990s have limits as to how much fuel they will deliver. This makes sense when one understands that delivering more fuel, without the ability to fully burn it and manage the by-products that pollute, would result in duplicating what the carburetors used to do. Hence, while all it takes is a screwdriver to increase the amount of fuel that a carburetor will deliver, there isn’t anything that one can do with the electronic components of a stock non-programmable system. The only thing that one can do is change the fuel management system. This is absolutely feasible, but installing a modern system is of course, more complicated than installing carburetors.
Best regards,
__________________
Enrique
Spider 74, 84 & 87
164 93L & 95Q
Milano 88 Verde
|
12-20-2007, 11:05 AM
|
 |
Registered User
|
|
Join Date: Jul 2003
Posts: 1,525
|
|
|
[quote=Zunige;464266] The increased fuel and increased air obviously will create a more powerful explosion, which will push the piston down with much greater force, when the mixture is detonated. /QUOTE]
Enrique, I agree with the benefits of modern electronic fuel injection. But you are perpetuating a misunderstanding by referring to a "more powerful explosion." The fuel/air mixture should "burn" in a controlled fashion, not "explode." Explosions are also referred to as "detonation" and are not a good thing!
Erik
|
12-20-2007, 11:28 AM
|
|
In the Spiders' nest...
|
|
Join Date: Jun 2005
Location: Nutley/NJ & Middletown/OH, USA
Posts: 4,627
|
|
[quote=genericwood;464309]
Quote:
Originally Posted by Zunige
The increased fuel and increased air obviously will create a more powerful explosion, which will push the piston down with much greater force, when the mixture is detonated. /QUOTE]
Enrique, I agree with the benefits of modern electronic fuel injection. But you are perpetuating a misunderstanding by referring to a "more powerful explosion." The fuel/air mixture should "burn" in a controlled fashion, not "explode." Explosions are also referred to as "detonation" and are not a good thing!
Erik
|
You are right, of course... I'm visulaizing what I described, vs. what you said, and yikes (!), my description could make pinging look good!
Best regards,
__________________
Enrique
Spider 74, 84 & 87
164 93L & 95Q
Milano 88 Verde
|
12-20-2007, 01:24 PM
|
|
Registered User
|
|
Join Date: Aug 2007
Location: Brisbane, Australia
Posts: 70
|
|
|
I went from a single 45mm TB on my Suzuki to quad Yamaha R1 carbs and picked up more hp and torque at much less rpm. Of course, CV carbs are a touch different than Webers but it was very worthwhile. Only thing better would have been ITB's. It's all relative to c | |
