Well at the beginning of my winter rebuild I never thought about getting a new converter. I rebuilt and re-aligned my steering / front suspension, put a new firewall in, built a new steering shaft, put turn outs on the headers to get rid of the turn downs that kicked up so much dust, rebuilt my 388 I ran before and am using Line2line coatings for the first time. I also am adding a new sfi bell to my trans and shortened my wheelie bars. I had to re-wire a bit after adding the new firewall. It's been a busy off season.

Reading another thread about converter stall / fallback really got me thinking so I called Marco and ordered a new converter. When I told him I footbraked my roadster he got a laugh out of it and thought it odd since very few roadsters are run in this class. My last converter would flash to 5800 off the foot and fall back 1000rpm after the shift. We agreed on needing to loosen it to 6200-6300 and have less fallback. I will come back to this post once I have made some passes this year and update how it's going. Anyway I just wanted to support the people who help keep this board up and running and thought I would make a post about how it works out.

Excellent update Curtis and will be following your new converter build after install. How many runs were on the engine prior to rebuilding? Same 4.060 pistons or new?

I recently watched THIS Bogacki FB video of Justin Lamb answering a converter question. What he recommends is 110% right imho.

Late last year I did a planetary change that increased the SLR considerably and I’m not satisfied with what I presently have for flash stall. I’m switching engines sometime late this summer and would like a change. Although my converter / transmission builder is 15 minutes from my house, every time I want something done it’s 3 weeks. Because of this I’m considering a new converter based on my last build of being cut two times to get it improved (what I originally requested). My experience of what I receive has been different than requested. I don’t call missing it 150+ rpm right. At $1300 a build I want it right, not close. Maybe I’m too fussy.

Marco is awesome, he nailed it on the converter for the TD and PST both. Great guy to work with

Mark I only had 306 runs on the engine. I had a self I diced problem that caused too much PtoW clearance and blowby got to be an issue. I threw my top end on an old 355 short block that was sitting under a table to keep racing. That was mid ‘22 and I have been racing with that engine until I had a head gasket go away at our last race.

The 388 is exactly the same as it was with a fresh hone, new rings and coated pistons to close up the wall clearance. I did switch to Mickeys last year but other than that it’s all the same so any differences should show up immediately. My old converter was an FTI 8” that was pretty aggressive to 60’. When I bought the FTI it didn’t flash as high as I had hoped but I think my light weight and low hp makes it tougher to get what I want. 60’ was 1.20 best and usually 1.24-1.25 in the heat. Low to mid 5.70s in the heat. All off the foot.

quote:

Originally posted by Big Steve:
Marco is awesome, he nailed it on the converter for the TD and PST both. Great guy to work with

He was cool on the phone. Said the only time he had been in Oklahoma was on his way to race Ennis. I told him it was probably a smart move to keep rolling through.

My 2 cars have a 6200,and a 6400 convertor, off the t-brake and chipped at 3600 on the bottom bulb car and 4k off the top bulb car fall back is about 800 off each on a small block car i would'nt run under 6k for a stall, we shift at 7k to 7.2k if you have a play back tach or data recorder you live in a 1k to 1200 RPM range anyhow if you play it back, this in the 1/8th

quote:

Originally posted by HR3377:
My 2 cars have a 6200,and a 6400 convertor, off the t-brake and chipped at 3600 on the bottom bulb car and 4k off the top bulb car fall back is about 800 off each on a small block car i would'nt run under 6k for a stall, we shift at 7k to 7.2k if you have a play back tach or data recorder you live in a 1k to 1200 RPM range anyhow if you play it back, this in the 1/8th

I do have a data recorder.

I'm running a Chance converter that I got used last year. It's way too tight, drops over 1600 rpm on the shift, yet I was still able to run a personal best with it. I did talk to Marty and got a different stator for it, but it flashed WAY too high, somewhere in the 7300 range. I'm putting a data recorder on the car now, and once I get a run or two with good data, we're gonna look at a different stator again. I'd love to just order a brand new one, but not in the cards. My old converter will get sent out at some point this year to get redone, and it will become my n/a converter.....

First lap it flashed to 6075 leaving at 2800 off the foot. Shifted at 6880 and fell back to 6201 hanging there .26 seconds. Ran 5.734 @115

Second lap I took 300 out of the shift. Flashed to 6105 same leave rpm shifted at 6620 and fell back to 6158 but after.02 started climbing. Went 5.756 @115.

The car is still picking up each pass though from the Line2Line coating sizing itself. So far I am tickled to death with it.

^^^^^^ What kind of air (DA) were you running in?

My weather station showed 1416’ and 1517’ for those 2 laps. Air was really dry though around 25-30 water grains throughout the day. Ran out of talent in the third round -.003 so I ran it out. Went 5.738 and air showed 1781’.

I was at the track when I posted earlier.

^^^^ How much faster is it now with the fresh rebuild and higher stall convertor given the DA yesterday than prior?

Too much to digest at this point to give a definitive answer. Gut feeling right at this point is that I slowed slightly. Was searching for consistency since I'm pretty quick already.

I will come back to this once I get more runs on it.

Well Mark, I got a few more runs on the car this past weekend. Things overall didn't go well for giving you solid info on this but because I have raced this car and engine/driveline combo so long I can give some feedback none the less.

The car has been slower in every increment but it's a better bracket car.

Friday I made 3 laps and was still in the race but had some oil pressure problems so I loaded up and went home to fix that. Track was not great, I was 1.25 and 5.77 out the back.

Saturday rolled around and the software for my weather station/log book stopped working so I can't give weather data compared to the past other than I know what I would have run looking at the weather on the time slip app. The track really came around with all the dragsters we had at a bigger money race. This is all footbrake though. I made a small shock adjustment and the car really responded. Weather on the app showed 2129' 69% 69° at the start to 3100' 53% 81° when I had to leave. Here are my times for the Saturday. I hope the formatting works.

10:23 11:27 1:09 2:27 3:18

TT TT 5.77 5.78 5.77

-0.010 0.045 0.044 0.037 0.043

1.250 1.241 1.243 1.243 1.246

3.671 3.654 3.658 3.656 3.650

5.774 5.754 5.815 5.762 5.883

114.88 115.07 102.58 110.53 97.70


As you can see I pulled in the lanes right. LOL Guys that I got had various problems, couldn't get there, broke out, couldn't get there/late. My lights I can bring down with an rpm change but the spread is good. Every other lap I have made this year has been between -.010 and .026 so my lights are coming around but need more laps to get were I want them.

The bad news is that I had water in #7 cylinder and had to put it away even though I was still in and head home. Overall I am more than happy with the converter even though I believe it is about .012-.015 slower in 60' and .05-.07 slower in the 1/8.

With my FTI I would have been 1.20-1.23 in the conditions I have seen. I have been 1.231-1.256 this year. 1/8 would have been 5.68-5.73 and I have been 5.73-5.77 on every all out run. Air has been from 833' to 3001' looking at he app. Pretty darn consistent.

Are you running in a FB only class or just FB in a Pro no box class?

I’ve not experienced going slow when loosening converter that flashed 600 +/- below shift point, but have experienced more consistency using looser. To me too loose would be less than 400 rpm from shift point at flash. But your car being so light might like tighter better. Lots of variables.

Too bad about the water leak problem. Somethings not right and hope it can be corrected. What type head gasket…mls?

It's footbrake only

1003 composite Fel-Pro

This motor isn't much. Only about 575hp 388 on Methanol.