question about accelleration

[mikeb1223]

First time ever owning a fiat spider and come from mustangs BMW and 300zxtt's my question is 1st and 2nd are awfully slow to me but it hits 3rd through 5th she's pretty good... The engine has been modded 38/38 Webber, four to 2 header, and bigger cams Idk the size of the cams but they are bigger... I just feel there should be more acceleration 1st and 2nd... It kinda sucks when a kia out accelerates you from a red light and they aren't even trying and I got my car screaming... Thanks for your time

[TStark]

You may be feeling the effect of that heavy flywheel.

[RRoller123]

I think 1st is geared way too low in general, you hardly need it, could just start in second (just kidding)

[81SPIDERMATT]

third is my favorite gear .... and you admit is seems slow "to you" ... not gonna win a whole lot of off the bat races ... but get that kia in the twisties ... that trade for me seems reasonable .... but if had the resources ...there are ways

[mikeb1223]

Its got the power Lol I need limited slip or posi cause 1st and 2nd when romping on it smoke the one tire lol

[RoyBatty]

Use caution on your drag race type launches.
Your going to soon find the strength of your stock ring and pinion.

These were never meant to be light to light racers in stock form.
They were meant for cruising with the top down on a country two lane.

[baltobernie]

You might have too much carb in the 38/38 for street use. Does it feel like its bogging down, or running out of breath?
What ignition timing are you running?

Generally speaking, low powered cars like ours have the opposite problem; they shriek in one and two, and take forever to gain speed in three and four.

[mikeb1223]

No the carb is tuned in perfectly and the spark plugs are grayish brown which is perfect and timing is 10 degrees... Just weird it feels slow for what has been done to the engine, kinda hate to see the performance of a bone stock engine Lol... But yeah cornering and twisties I put it with my 88 BMW M3 when it comes to that.. I'm very happy with that

[vandor]

I don't understand. In the first thread you say it seems low on power in first and second gear, but in a response you also say that you need posi because it smokes one tire in first and second. If it can smoke a tire, how can it be too slow?

FWIW even a stock Spider can spin the tires in first and likely get some rubber when shifting to second.

[4uall]

Best burn out of all time IMO Opening scene work safe

https://www.youtube.com/watch?v=5qanlirrRWs

[mikeb1223]

Burning a tire and acceleration are 2 different things. Offline acceleration is just slow to me but on the other hand it will smoke a tire.. For what's done to the engine just seems it would be faster off the line

[azruss]

you dont tell us what engine you have. Road tests on these cars show a 0-60 in the 12 second range. With the exception of the turbo, this remained about the same through the years. You are comparing it to much more powerful cars. The modern soccer mom van will do an 8 sec. 0-60. Acceleration off the line is a function of torque, not horsepower. You get torque from displacement and mild cams. Longer duration cams will raise your horsepower and its peak rpm and will lower your low end torque. As you get up in the gears, then horsepower comes in to play. Horsepower is required to push through wind resistance. As with most sports cars of its day, these cars have small motors with a 1 hp/cu in. ratio. They were made in countries with lots of curvy roads and country driving and that is where these car excel. These cars also came stock with 165x13 tires and this was plenty of engine to drive tires of that size. Just remember, these cars look fast and if some car beats you, then they just don't think you are trying. My kids were in high school when my 70 had a very tired 1438cc. It couldn't even beat a bug. Yet, the car had a reputation in the school as a car so fast, you didn't even challenge it. My kids learn a very valuable lesson about perception vs reality.

[mikeb1223]

Makes since Lol... I get tons of looks and many offers to buy it I do love the car.. The guy I got it from did all the work it has 3 angle valve job 10.1:1 ratio pistons. Bigger then stock cams I just can't remember what specs he told me, single plane intake with a weber 38/38 carb exhause is 1 1/2 headers 4 2 1, 2 1/4 pipe to a Borla muffler ... Sounds great.. I know he dumped a lot of money into the engine I just thought it'd be faster Lol ... I have to change the tires in the rear they are 205/60/13 Yokohama race tires the are wore down pretty good they are like a compound like NASCAR uses a hard race rubber. I'm also thinking there's a lot of wheel spin maybe when taking off and no sound PR smoke coming from them and maybe that's where I'm feeling it should accelerate faster maybe

[Exit98]

Mike,

I don't see what year your Spider is. If its before 78 or 79 (not sure exactly) then it has a 4:10 rear. Later rears are 3:90 and are an easy swap.

Now I know that changing to the late rear end gearing will reduce acceleration times. I can't argue with the math. But the change also widens up each of the gears and makes each one more useful. After making the switch I have no seat-of-the pants sense of slower acceleration and the car is much more pleasant to drive, not only with the 400 or so less RPM's at 70 MPH, but also around town. Third gear is a pleasure in particular.

Like someone said on here a long time ago, with the old gearing I was shifting to fifth by the end of the driveway.

Offsetting the negative impact of the 3:90 rear on acceleration is the lightened flywheel I installed. Between the flywheel, the 34 ADFA Weber and the 4-2-1 and complete de-smog I believe I have a net gain in 0 to 60 while reducing high speed RPMs.

Not everyone agrees with me on this. But I've had it both ways and won't go back.

[mikeb1223]

I'm sorry its a 1980 .. Stripped also of all the smog stuff ... Makes more since with gear ratios I didn't know it had 3.90 gears