4.1 results

D

DougsfastZ

4.1
Joined
Jan 30, 2004
Car was down for almost 2 years and wanted to update the results of my 4.1 production build. The evolution of the car is listed in my signature. Earl Brown provided the pistons and it was difficult to find a usable 4.1 production core. The motor ended up with a girdle and static compression of 9.55:1. The track was not working at all in the video below, which is not like this car. I typically cut mid 1.5x's shorts and couldn't get it too work, hence the spinning and softer launches. I think part of it is due to the turbo coming in harder with the 4.1 over the 3.8. Started the night with 20 psi and 18/16 timing and ended up with 25 psi and 22/20 timing. Overall I'm happy with the results and should turn the wick up in fall.

 
Assume you have the powerlogger with the SD TT chip? Any hints in there, too rich, alky hitting too early or late? Converter too tight? Try lowering tire pressure?
 
Nice job on your build and very good numbers on a new combo! I bet Earl is a proud papa....you should see if he'll give you a rebate for the good press.;) Just kidding I know he has a lot of time and effort in the piston project and I'm happy for both of you!
 
I have been down this road more than a few time with a 4.1 build and a TE-45A, including my current street car, your car will never see it's potential until you get the proper torque converter in the car.

We have proven this build will easily run low 10's to high 9's when done right.
 
Looks like you were traction impared all night. I say 129 mph in the 1/4 on your first time out is nothing to frown upon. Looks good, sounds good, runs good. I dig it! Congrats on getting her back together. I can't wait to see her run again!
 
DougsfastZ said:
.................... I think part of it is due to the turbo coming in harder with the 4.1 over the 3.8.
Click to expand...

I do not want to get into a pissin' contest with you, but your statement indicates the converter is too tight since the turbo is not able get up to speed for a kick-ass launch. Instead the converter couples and spins the tires.

I never use less than a 3600 NLU converter with a 45A, and my personal car has a 3800 NLU stall which will shoot the car out of the hole with no tire spin, street or strip. A low 1.40 60' is normal for my car, better when I use the transbrake

Your car, your money, but I have loosened a few of Dusty's converters, and other brands as well as some of mine to fit a specific build.

But I am just trying to help, and this is my opinion based upon a dozen TE-45A or so cars I have built.
 
With the ptc when you turn the wick up and hit it with more power the converter will loosen up.the low boost behavior is very different from high boost.
 
Nick Micale said:
I do not want to get into a pissin' contest with you, but your statement indicates the converter is too tight since the turbo is not able get up to speed for a kick-ass launch. Instead the converter couples and spins the tires.

I never use less than a 3600 NLU converter with a 45A, and my personal car has a 3800 NLU stall which will shoot the car out of the hole with no tire spin, street or strip. A low 1.40 60' is normal for my car, better when I use the transbrake

Your car, your money, but I have loosened a few of Dusty's converters, and other brands as well as some of mine to fit a specific build.

But I am just trying to help, and this is my opinion based upon a dozen TE-45A or so cars I have built.
Click to expand...

Thanks Nick, I'll call Dusty to discuss.
 
Believe it or not still at it with the car. Lost the apply band on the ~8 year old Lonnie built transmission back in Sept of 15'. Rebuilt the trans myself in July (with Lonnie's awesome help) and put a few 100 miles on the car on waste gate spring. Took it to the track on Friday and went my personal best three times in a row. My buddy is racing in this video where it cut it's best short of a 1.49 on the foot brake. Car went a pair of 1.52's earlier in the evening. It went 10.36 twice and a 10.37 in the 129-130 range. Picking up 25 mph in the back 1/8th, we kept adding boost through the ISAC and we weren't seeing any increase of 25-26 psi through the pass. Mike (Vin7) found the medium wastegate spring in the JGS 400R was too light. Ordering the heavy spring so I can hopefully get to 30 psi. Car did not react at all to adding 1.5 degrees of timing on the base 21/19 that Eric burned on the SD chip.

 
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