H.0.?

[Warbeaver]

I may sound dumb, but what does H.O mean on a grand am?

also, does anyone know what a drilled means in relation to a thermostat?

[Jchiasson]

HO = High Output

[Shadow-D]

I may sound dumb, but what does H.O mean on a grand am?

also, does anyone know what a drilled means in relation to a thermostat?

HO = High Output

Drilled = This is used for racing, rather than having a tstat that opens and closes you have a thin metal plate that has a hole drilled in it to allow coolant to pass through.

[Ralph]

on the 3400s the HO doesn't mean much

[sunrunner_pei]

I may sound dumb, but what does H.O mean on a grand am?

It depends on what you're referring to. The Quad4 H.O. was a much improved version of the Quad4. The 1999 Grand Am GT was labeled as having a 'V6 H.O.' However, the 1999 was no different than the 2000-2005 Grand Am GT that was re-badged to read 'Ram Air V6.' The engines are the same from 1999+, both feature Ram Air. It was just a marketing decision.

[Matt95GT]

HO = High Output

Drilled = This is used for racing, rather than having a tstat that opens and closes you have a thin metal plate that has a hole drilled in it to allow coolant to pass through.

Never seen anyone racing do that... usually a consistent ECT is desired. Every instance of drilled T-stats I've seen is a cheap band-aid instead of properly diagnosing cooling system issues.

In other words, you shouldn't drill your T-stat.

It depends on what you're referring to. The Quad4 H.O. was a much improved version of the Quad4. The 1999 Grand Am GT was labeled as having a 'V6 H.O.' However, the 1999 was no different than the 2000-2005 Grand Am GT that was re-badged to read 'Ram Air V6.' The engines are the same from 1999+, both feature Ram Air. It was just a marketing decision.

Yup. In context of the 99 GA, it doesn't mean much. (~5HP over SE) In the 89.5-94 GA, the Quad 4 HO had a minimum of 20 HP more than the non-HO (LD2 DOHC) of the same year, plus all were 5-speed manuals.

[Warbeaver]

that makes sense. im just getting a 180* thermostat but it asked if i wanted it drilled or not.

I dont think mine is high output yet lol. Its mostly just a stock, clean GAGT coupe 75th anniv edition. but it will be modded once im done. Im getting a CAI, 180* stat, plugs, wires, head unit, ram air hood, borla exhaust, rims, tint, and other misc things. I just have tailights and stuff on it now. I polished the stock tips last nite. its extremely clean. I will have a signature soon with pics of it :D

[daman]

If your running a 180 stat i would n't drill it.