Alfa Romeo Owners Club of Australia Forum

Technical => 160 Series (90, 75, 164 Sedans) => Topic started by: hammer on November 28, 2007, 10:17:55 AM

Title: Any tips on performance chip for 75 Twinspark
Post by: hammer on November 28, 2007, 10:17:55 AM
I want to look into the possibility of a chip upgrade for my 75 Twinspark but am unsure where to begin. This car is being transformed from stock standard road car to a track machine. I've stiffened the suspension, stripped the interior, added a cage, am having a better flowing exhaust made and thought that I would investigate possible upgrades to the engine management system.

Are there any Twinspark experts out there who have done a chip upgrade that they could recommend? There are no other AROCA club members racing Twinnies up here in Qld, so I'm treading new terrain.

Any advice would be greatly appreciated.

Cheers,

Brent
Title: Re: Any tips on performance chip for 75 Twinspark
Post by: Jekyll and Hyde on November 28, 2007, 06:22:47 PM
If you are going all out with a track weapon (sounds like it!), you'd be better off with an Autronic/Motec etc, as it will allow you to retune for other mods later, and throw out annoying heavy items like the air flow meter (allowing for a bigger diameter intake pipe  ;D).  The performance from such a setup would translate to enough seconds on the track to justify the extra cost, as the stock ecu is still a 15+ year old design which was created with that annoying E-word in mind as well as performance - economy.  Assuming that you can in fact get a chip for it, you are still quite limited with what you can do inside the constraints of the original ECU.

If you were to run a fully programmable ECU, you should be able to take control of your spark advance curve, remove various annoying emissions items (not sure what they are on a TS), and generally set up a much better intake system (ie. make up custom manifolds at a later date, bigger/different injectors, wild cams....)  Then again, regulations for your target class may not allow this.

  However, if you can do it within your class, I'd go straight for the fully programmable ECU right off the bat, even if you don't intend to make any more mods at the current time - the ability to fiddle with just the fueling alone should see you able to dial in a faster car than a chip can give.
Title: Re: Any tips on performance chip for 75 Twinspark
Post by: hammer on November 28, 2007, 10:33:36 PM
Thanks very much for this mate. I'll do some pricing on these units and see what I can get. Bob Romano down the road from my place is a dealer for Haltech, so I might look into how they perform.

Thanks very much for the advice. We're off to Qld Raceway for the final sprint round of the year on Saturday and rain is predicted, so it could be interesting.

Cheers,

Brent
Title: Re: Any tips on performance chip for 75 Twinspark
Post by: Victor Lee on November 29, 2007, 05:39:26 PM
Concur with Turbo!

A good ECU allows to do so much more than an off the shelf chip (if one exists for your car).  For example, see my post in the thread about popping plenums about the versatility of what an ECU can do:

http://www.alfaclubvic.org.au/component/option,com_smf/Itemid,68/topic,912.0/


In Melb, there's a twin spark in a 105 using (i think) Autronic.  But since it's a street/sprint car, it's only mildly tuned.  Hugh Harrison at Alfpa Repairs built that motor.
Title: Re: Any tips on performance chip for 75 Twinspark
Post by: hammer on November 29, 2007, 07:09:19 PM
Thanks Victor. I'll certainly speak with some after-market ECU manufacturers to see what the options and costs are.
Title: Re: Any tips on performance chip for 75 Twinspark
Post by: AR116 on February 10, 2008, 11:38:51 AM
The best thing to do to any alfa 75 engine would be to install a microtech lt10s ecu with an x4 igniter. This would eliminate the need for an air flow meter. You may also remove both distributors and run coils for each spark plug, hence running a full wasted spark system. Then improve the air intake system and also the exhaust system to help the motor breath better. If performing some of the work yourself this setup will cost just under $2500.

Title: Re: Any tips on performance chip for 75 Twinspark
Post by: hammer on February 11, 2008, 05:36:43 PM
Angelo,

Thanks for the advice mate. I decided to hold off on an aftermarket ECU until I build a new engine - which will be next year. For now I have put on a 2 1/4 inch exhaust, with larger diameter secondary pipes and my mechanic has fashioned up a more direct air intake, which comes in adjacent to the driver's headlight. I also removed the power steering to grab a couple of extra ponies then had the whole thing dyno tuned. The net result of all this was 22 additional horsepower at the flywheel for less than $1000. That will do me for this year. Now it's back to the task of weight reduction.

Thanks again for your advice though and I will definitely take it onboard in 2009.

Brent