I took off the undertray on my coupe and i feel a little bit of drag at low speed. Does anyone in here experienced the same problem or its just mind over matter.

Clover, I'm not sure exactly what you mean by 'drag'. I can say that I have heard of coupes running both with and without undertrays.

On the turbo models I have heard that running without an undertray does seem to make the car noticeably quicker - the most probable reason being that there is much more air turbulance inside the engine bay which generally yakes a few degrees off all the air-inlet temperatures, especially around the intercooler.

The downside is all the crap that gets sprayed up from the road surface. The oil cooler pipes are particularly vulnerable being so low down in the engine and corrode easily (especially if they put salt on the roads).

My advice would be to have the undertray fitted as it is much better for the reliabilty of the engine long term.

SpunkyM...
Fiat Coupe 20VT, Bailey DV, K&N panel, PBV @ 1.1bar.

Spunky, What i meant by 'drag' is the car is slower as the undertray works as a ground affects where it flow wind smoothly underneath.... i took it off hoping to have better engine tempreture but it seems not much different tho. I think the car is slower now.

Clover
Fiat Coupe 20VT, Turbosmart TypeIII DV, Hybrid T28 (48mm compressor wheel), klon chip, Custom Stainless Steel intercooler piping, K&N filter element, 35mm B+G springs, Tarox G88, AP Lockhead Pads, 3" piping, cold air feed, Apex'i boost meter & turbo timer.

Understood.

It will effect the lineararity of the airflow under the car to some extent and it may even alter the downforce of the car at high speed (reduce it slightly maybe).

If you don't think it is helping you in terms of performance then it makes sense to keep the undertray on.

PS. quite a list of mods there you got on you coop <img src=icon_smile_approve.gif border=0 align=middle>

SpunkyM...
Fiat Coupe 20VT, Bailey DV, K&N panel, PBV @ 1.1bar.

Spunky,
I was thinking of making the car faster but due to financial constraint can't do much. After upgrading from an alfa 145 boxer i thought the coupe had enough bhp but then the coupe is like a drug the power is never enough. Finding rims for this car is bitch too... the only rims available here are the AVEZ or Momo GT2.

The problem with this car is a lot of Protons with VR4 or EVOLUTION engine can smoke the coupe no problem and that really pisses me off. When my turbo seal leaks again i'll probably buy a used japs turbo (IHI or mitsu) and install it in the car and get rid of the cast iron manifold and custom a stainless steel one. Then unichip it to get enough fueling.

Clover
Fiat Coupe 20VT, Turbosmart TypeIII DV, Hybrid T28 (48mm compressor wheel), klon chip, Custom Stainless Steel intercooler piping, K&N filter element, 35mm B+G springs, Tarox G88, AP Lockhead Pads, 3" exhaust piping, cold air feed, Apex'i boost meter & turbo timer.

Yeh - the wheels are a real problem, it's those bitchin Brembos that stick out so far - O.K. they are forgiven as they look so cool but it is a bit of a pain. I guess like yourself, I never really felt comfortable with spacers under the wheels. Luckily the std 20VT wheels don't look too bad, well better than the non-turbo anyway.

A word of warning with the stainless manifold - the Mariani ones crack so I guess others will have the same problem. The manifold on the 20VT is extremely stressed and Fiat had to redesign it in 1998 to get it right.

SpunkyM...
Fiat Coupe 20VT, Bailey DV, K&N panel, PBV @ 1.1bar.