fieroguru at lsfest
Posted: Sat Sep 28, 2013 4:40 am
How did you do? I haven't seen a thread on Old Europe about it. If I missed it feel free to post it here
The trip down the car averaged 29mpg again... breaking the 30 mpg mark is looking to be difficult.
On the first day of LS Fest, I was able to do ten 1/4 mile runs and six passes on the autocross track. Overriding theme is the car has too much power/not enough traction.
On the drag strip, I started out going though the water box, quickly nixed that idea as I would launch quicker w/o any pre-launch burn out. I also started out launching the car right off idle in 1st gear... Doing this I would still spin at the top end of 1st, which was hurting my ET and MPH. So I started launching in 2nd gear... slower out of the hole, but resulted in my quickest ET and mph of the day. Even launching in 2nd gear, wheel spin still happens as I feed it more throttle... need better and wider tires.
The major issue with 1/4 mile performance is the 2-3 shift... its like the syncro locks me out of the gear and I have to hold/apply pressure to it for well over 1/2 second for it to slide into gear and commence with the run. I am shifting at the same RPM (about 7k) but the 1-2 and 3-4 shifts both happen relatively quick. I adjusted the throttle follower torque to pull more torque so it would close faster early on with the tune. So its possible the engine is now dropping RPM too fast and passes up the RPM of the 2-3 gear shift before I get the shifter pushed up and over. The 1-2 shift has a larger RPM drop and the shifter is pulled straight back so there is more time to grab second and its a quick shift being pull straight back. The 3-4 shift is also quick... so I think I can just pull the shifter back quicker than forward and to the next gate over. So tonight I will tweak the throttle follower in the 4500-7K range to see if it helps the 2-3 shift by dropping RPM less quickly.
Best time of the day was 12.896 @ 114.10 mph... I know the car has more in it if I can get it to hook and speed up the 2-3 shift.
The 6 runs on the autocross were all steps towards a better time. 1st run I DNF'd as I missed the first cross over turn and the announcer came over the intercom "your going the wrong way"... 2nd run was 57.089 where I spun out on the back stretch, then 44.908, 44.784, 42.699, and 42.294. The best time of the day was in the 36 second range, so my times suck! I run the course in 2nd once I take off in 1st, but traction in 2nd gear is easily overcome in the straight line, let alone going around a corner, so less throttle lets the car go faster.
The car really needs a driver mod, wider stickier tires especially in the rear, and fix the 2-3 shift issue... but its been fun flogging the car!
Gearing being the same, torque is what matters here.Aaron wrote:Before I go into the questioning, mad props for the quality build and actually racing the car.
Now the question I have. He mentions over and over his traction problems. Who here has traction problems in their swapped Fieros? I'm on stock wheels/tires/suspension/Getrag, and if I hammer it from idle, it will hold traction in every gear. If I try I can spin the tires in 1st without a problem, but it takes concentrated willful effort. The car won't do it on power alone, and certainly won't in 2nd.
I'm wondering why this is? I have little doubt I'm making more power than he is, although he has me beat in torque of course. I guess that could be it, but I'd think my car would go crazy when the turbo comes on and I gain 200whp and 200wtq in 1,000rpm. Instead my car just squats hard, plows the front end, but hooks the rear.
It just seems weird how many people mention traction problems, and I haven't run into any. And it isn't because I'm not making the power, I put car lengths on my Jeep which runs 12s. I hate to jack this thread, just seriously confused.
Yes, everything is in my build thread in the construction zone.Shaun41178(2) wrote:How did you do? I haven't seen a thread on Old Europe about it. If I missed it feel free to post it here
Yeah, he was cool to hang out with. Our cars are within about 10-15 whp of each other (his is higher), but the power bands are quite different. He was having major traction issues (stock fiero 14" wheels and stock sized tires) with 2nd gear launches, so I suggested he use less launch RPM to get out of the hole and let the torque of his engine do the work. He probably has 100ft-lbs more off idle than I do. This resulted in his best trap speed of 116mph. We were able to run head to head on one race... I just wish someone would have video'd it as you don't see 2 fieros heads up that often.Shaun41178(2) wrote:Just noticed jgunset had his ls3 Fiero there and ran a best of 13.05
I was having traction issues at both ends of the car, rear wheel spin and locking up the fronts on the autocross. The front is largely due to the 205 all season front tire and needing to do some work to adjust in more rear bias (never locked up the rear).Aaron wrote: Now the question I have. He mentions over and over his traction problems. Who here has traction problems in their swapped Fieros? I'm on stock wheels/tires/suspension/Getrag, and if I hammer it from idle, it will hold traction in every gear. If I try I can spin the tires in 1st without a problem, but it takes concentrated willful effort. The car won't do it on power alone, and certainly won't in 2nd.
I'm wondering why this is? I have little doubt I'm making more power than he is, although he has me beat in torque of course. I guess that could be it, but I'd think my car would go crazy when the turbo comes on and I gain 200whp and 200wtq in 1,000rpm. Instead my car just squats hard, plows the front end, but hooks the rear.
It just seems weird how many people mention traction problems, and I haven't run into any. And it isn't because I'm not making the power, I put car lengths on my Jeep which runs 12s. I hate to jack this thread, just seriously confused.