Slow acceleration and loose clutch on Manual Car Even with a Brand New Clutch kit installed.?

Does the clutch pedal have freeplay measured alonside the pedal? Then depress the pedal to begin clutch release, what is that measurement of downstroke before effective?

When you engage the clutch to operate, how far from the floor is the pedal when the wheels begin to engage?

Can you enter every gear pressing the clutch once ?

Did you use acura parts?

Is it possible your parts measure differently than the correct parts?

is there some issue in the clutch hydraulic parts? causing partial release?

You see, a tech must use judgement and have familiarity with yours to note where something is out of spec, feels funny, or stays applied or released. Inspections, measurements, tests may follow,

or removal, comparisons at the parts counter can reveal some issue?

a foreign object interfering can cause good and correct parts to malfunction, so can improper assembly.

Who's your mechanic? Does it say acura on his shirt?

or OMFGWAPOS!

Give a list of part numbers or run all the tests, or both, till you find it.

It's easier to goto them, unless you are that brave and determined.

Part of doing a correct clutch job is having the flywheel turned or resurfaced. You use the term "loose" clutch. If you mean too much free play in the pedal, this would not contribute to slippage. Too little free play (the clutch releasing clear up at the top of the stroke) would cause the problem and adjustment would solve the problem. If you used a re-manufactured pressure plate, this could prove to be a problem. I used these for a while at my business but had nearly a 10% failure rate. We started using only new parts.

If you installed a new clutch that eliminates the problem of a bad clutch and I really don't think you could have done it wrong, it only goes one way if you had put the clutch disc in backwards it would be making all kind of noise. So that leaves the slave cylinder. When the clutch is all the way up you should be able to turn the rod going to the clutch fork with your fingers. I believe you will find out that you can't and you need to find out why and fix it.

Did you replace the scorched flywheel?

either put together wrong or it needs to be adjusted