4c vs 5c converter

I'm at the track. How are you all lauching the all motor cars?

My car liked being stalled as high as I could get it with my 4c

All I really need was a 1.71 60ft but that didn't happen. Car trapped 115.3, after the converter. So the tune was working with 91.01 mph in the 1/8. HOWEVER, I couldn't run 11s on motor. Best 60ft was a 1.78 60ft and alot of them was 1.8xx 60ft. So how do you launch your cars on the 4c or 5c converters? My tires are the 305/35r19 Nitto nt05r tires, and I'm on the 3.15 Rear. I need some gelp please. I started at 20 psi, 15 psi, and then 12 psi.

NicksRubyRed15GT said:

My car liked being stalled as high as I could get it with my 4c

Click to expand...

What's your 60' and 330'?

bunch of side shoots going off of my original thread here, but thought i would update everyone.

4c and headers are in. went to the track last week and went 11.93 @ 116.9 on a 1.71 60'. the 555r tires are a problem now lol. best launch was brake stall to 2k, roll out, then stab it. if i tried to flash the converter on the hit it would spin then shortshift 2nd and run 12.2x everytime.

edit- DA was in the 1500 range all evening. i feel like my mph was low too...

hawk232 said:

bunch of side shoots going off of my original thread here, but thought i would update everyone.

4c and headers are in. went to the track last week and went 11.93 @ 116.9 on a 1.71 60'. the 555r tires are a problem now lol. best launch was brake stall to 2k, roll out, then stab it. if i tried to flash the converter on the hit it would spin the inn shortshift 2nd and run 12.2x everytime.

edit- DA was in the 1500 range all evening. i feel like my mph was low too...

Click to expand...

Congrats............on the PB. Thank you for the update. I will try your launching style at my next track outing. Can you share more information on your tires size? I saw your signature. How does your full slip break down? I would be really happy with a 11second Daily Driver, that's so bad ass. I believe the more information we share the faster we all may go.

Rhamlinii said:

All I really need was a 1.71 60ft but that didn't happen. Car trapped 115.3, after the converter. So the tune was working with 91.01 mph in the 1/8. HOWEVER, I couldn't run 11s on motor. Best 60ft was a 1.78 60ft and alot of them was 1.8xx 60ft. So how do you launch your cars on the 4c or 5c converters? My tires are the 305/35r19 Nitto nt05r tires, and I'm on the 3.15 Rear. I need some gelp please. I started at 20 psi, 15 psi, and then 12 psi.

Click to expand...

Were you spinning with your launches? I assume you were by the fact you were dropping air pressure. If you are spinning are you spinning right off the start or is it spinning a little out?

With the NT05R 305/35r19 you shouldn't be that low in air pressure. Most 19"-20" radials are going to work well with that little of air pressure in them. I don't have my data in front of me. But I think I had my NT05R 315/30/20 at 24-26 psi. I was actually going back up in pressure as the car was still dead hooking at 26 psi.

hawk232 said:

bunch of side shoots going off of my original thread here, but thought i would update everyone.

4c and headers are in. went to the track last week and went 11.93 @ 116.9 on a 1.71 60'. the 555r tires are a problem now lol. best launch was brake stall to 2k, roll out, then stab it. if i tried to flash the converter on the hit it would spin then shortshift 2nd and run 12.2x everytime.

edit- DA was in the 1500 range all evening. i feel like my mph was low too...

Click to expand...

Having to roll out is negating the benefits of the higher stall converter. Get it to hook and you will see the ET drop.

Play with air pressure to see if you can get the tires to work better. They are not a horrible tire, but there are better tires out there.



Track prep plays a big part of getting a radial to work. If the track isn't prepped well, is too cold, too hot, or humidity is high, all of that can lead to a radial to not work well. Especially if you do not have an adjustable suspension. Try to talk to other radial cars and see what their take is on the track. If you are there early enough to watch the prep and walk the first 100'. Get used to how the track feels in relation to how you end up hooking. So you can start feeling out how the prep changes and the changes the car will need to work. It isn't an exact science, but it will point you in the right direction at least.

86merc said:

Were you spinning with your launches? I assume you were by the fact you were dropping air pressure. If you are spinning are you spinning right off the start or is it spinning a little out?

Click to expand...

Yes, it spun to a 1.780 @15 psi cold. It did it twice and both time it short shifted 2nd and the car did 12.20s.So we tried 15 psi and 12 psi hot. However instead Of D and S modes. We manually shifted our way to 12.086, 12.079 and 12.055. It was a 5.0 330' aswell. As soon as you let go of the brake it spins. Trying different RPM launch rpm from idle to 2800. The car left like a dog under 2k. We played with the launch RPM, but off the foot brake it cant hold more then 2800 and then flashes to 3600-3800. Its setup for Full slip in 1st gear, and 1200 rpm desired slip in 2nd, full lock up in 3rd. It now shifts into 4th now aswell but I hold out 3rd if manually shifting.

I stall mine just before the tires break. This is really old on my 3C and 3.15's but you get the picture. Make sure your burnouts are good too. Best results I've got are from M&H 275/50/17 (compared to 3 M/T ET Street R sizes I've tried)

[ame]

Here's my best run showing outside the car with the burnout (I actually like a tad longer). This is 5C and 3.55's with a 1.51 60' on 275/50/17 M&H at 18-20 psi

[ame]

86merc said:

Track prep plays a big part of getting a radial to work. If the track isn't prepped well, is too cold, too hot, or humidity is high, all of that can lead to a radial to not work well.

Click to expand...

I agree with the track prep statement. I've found that different weather conditions call for different tire pressures. I run 16 psi when it's above 60 degrees out. I'll go as low as 14 when it's cold. You have to experiment. I've been 1.55 on all stock suspension.

bluebeastsrt said:

I agree with the track prep statement. I've found that different weather conditions call for different tire pressures. I run 16 psi when it's above 60 degrees out. I'll go as low as 14 when it's cold. You have to experiment. I've been 1.55 on all stock suspension.

Click to expand...

You've helped me thus far. I'm just far from your results which is frustrating. Im going to air them up. I would kill for a 1.55 60ft.

Mark5825 said:

I stall mine just before the tires break. This is really old on my 3C and 3.15's but you get the picture. Make sure your burnouts are good too. Best results I've got are from M&H 275/50/17 (compared to 3 M/T ET Street R sizes I've tried)

Click to expand...

What 60ft did you get in rhe video with the 3c? That 5c seems amazing.

Rhamlinii said:

What 60ft did you get in rhe video with the 3c? That 5c seems amazing.

Click to expand...

Best with 3.15 and 3C setup was 1.64 and consistent 1.64-1.68 on shorter 26" tires. 28" 1.68 was best and 1.68-1.79 consistent. Also 200 lbs heavier.

Went to MIR. To test alot of information of what was posted in this thread since my last track outing. I Started at 25 PSI, and that resulted with a 1.909 60ft, and then 22,20,17, and finally 15. All passes except the 1st was 1.8 60ft except the 1st. All 60ft's went lower as we decreased pressure except the last where it went from a 1.805> 1.829 on the last run. Each burn out was from 5-10 seconds. Best 60ft was 1.805 of the day. I would go into the 1st beam with foots on brake and gas. Pull up the parking brake on the last yellow. Then floor the gas, only to release the brakes when I saw green or the last yellow. Car would stall to 2800-3000, I would let then see the car pull to the 1st> 2nd ahift, and again on the 2nd> 3rd shift in s mode and let ot shift itself. DA was horrible so I wasn't going for records. This is also after a retune, where the car made 403 and 380 peak tq and went 12.055. I was on the new tune of 424 and 393 setting thru the 4c converter for this track outing. I'm going to do a alignment. After the track. I ask a friend to do a quick rinse of the tires to get rocks off of the tires. Looking at the burn out patch, it's obvious i'm not using all of the Tire. That may be why the car was spinning at launch. So i'll update again with new information as I get it.