so i recently bought an e55 off of the classifieds here. i have drag raced for many years with ls/ gm cars, not new to cars but new to german cars. the car i got has a renntech pulley, headers, tune and supporting cooling mods.

the problem i have i kind of outlined in the title, if i floor the car at a low enough mph to get it to kick down to first gear it spins hard and revs out in first and throws the trans into neutral. i have to pull over, shut it off, and start it back and everything is OK. i got a code one time and the car has done it maybe 10 times. the code was "INCORRECT GEAR RATIO" which i believe was p730.

now, if i ROLL into first gear and it doesn't spin like crazy it will shift ok to second.. this is very difficult to do with the limited traction and i have to manually have it in first and really feather it. if i tip into the throttle too hard and it spins hard it will kick into neutral

i did not locate a STAR as of yet to read any trans codes, the dealer wanted 150$ to check it so i tried my luck with the conductor plate

i searched and searched on this issue. i replaced the connector, checked the tcu and harness for fluid wicking, replaced the conductor plate/fluid/filter. no good, it still does it. the fluid looked great, the magnet had a little sliver on it but nothing alarming.


i asked the previous owner about it, apparently it mysteriously never happened to him he says anyway, and he commented that driving it like that was "abusive". if these cars can't handle being floored from 20mph and spinning the tires i wish i would have never bought it. i love the car but i can't enjoy something i have to worry about.

i surmise it is in the trans tune, as in the shift point has to be dropped a little to compensate for the fast and high revs during the first gear tire spin. it is cold out here, about 45degrees tonight so very little traction. i do plan on getting some nitto 555RII's for the rear, which might in itself fix my issue since i will get some sort of traction in first gear.

thoughts, advice, recommendations... any experienced help is appreciated. as i said i did search this a few times, i have never seen my particular circumstances for the trans kicking into neutral

 

Did you check the fluid level with the proper dipstick tool?

 

yes fluid level was verified cold and hot temperatures/ levels with the mb tool.

 

That was happening to me when I swapped gears in the diff. Is your tcu tuned? Try to borrow a stock tcu or buy one off eBay. I put a tcu in from another car with the gears I put in and magically it doesn't pop out of gear anymore

 

i was told the tcu is tuned via renntech. thanks i will start looking for a used tcu and/or somebody to let me try theirs.

i am in hatboro pa 19040 if anybody local is feeling like helping, i'll buy the nice guy a case of beer for his troubles, or lunch or whatever.

 

I had same thing happen to me ,bought another TCU off eBay,verified it worked normally ,then it would do same thing if I beat on it ,sent it to Kleemann they did reprogram and fixed it,as far as I can see they raised rpm shift points,my car has a lot of mods ,I put on pilot super sports and they hook so good it would have stopped the crazy spinning I had with the other tires nd it wouldn't have happened lol,my car never did it on qtr mile runs,only if I was stopped and punched it and it smoked first into second,FYI, I changed fluid and filter didn't help,shifter plate was good and i have blue top solenoids ,

 

^ ok that is kind of what i was wondering, guess i had it backwards with the shift points raised/ lowered but it was the same problem i have and a tune fixed it which is good news.

now i guess i have to drop 600$ to 1000$ to move one shift point you gotta pay to play right? lol i am planning on getting 100 tread ware nitto 555rII's that should hook (better anyway) but i think i will have this other problem always in the back of my mind when enjoying the car..

anybody recommend a local tuner, maybe somebody who understands that they only have to adjust one thing and might charge a little less

 

I'm not 100% sure if this relates to your issue, but I'll share my own personal experience.

I've got a Eurocharged ECU & TCU tune on my 2006. If I hammer the car from a stop and accelerate with wheel spin through 1st gear, it seems to "hang" at the top of 1st gear and doesn't want to shift into 2nd. It just hits the rev limiter and stays there. If I ease off the throttle slightly the car will finally shift into 2nd. I don't get any codes or errors...it's just an annoying hiccup that I've discovered and would like to resolve.

My theory: When ESP is working to resolve traction issues (tire spinning) AND the engine is up against the rev limiter, something in either the TCU or ECU is not coded properly. Call it a "bug" I guess.... In that specific set of events, the car just doesn't respond correctly.

Additionally, the increased RPM limits on both the ECU and TCU might be adding to the problem... As quickly as the engine rips through the revs in 1st gear, it might make more sense to set the shift points on the TCU a few hundred RPMs lower than the ECU anyway... In the time it takes to initiate and complete the shift (a few hundred milliseconds) the engine is already bouncing off the rev limiter. I suspect that starting the shifts 200-300RPM before the engine redline could resolve this anomaly.

To test: I'm going to install a stock TCU (with stock RPM shift points) and see if that helps with my full-throttle shift issues.

-G

 

cool let me know how it works for you. i agree i believe i am hitting the limiter and/or something is not in sync which is confusing the ecu and throwing it out of gear.. due to the very fast revs in first gear with no traction.

i know my way around hptuners for the ls vehicles, and i have tuned quite a few 4l60e 4-speed automatic transmissions. for wide open throttle shifting they use mph and rpm parameters to tell the trans to shift. both the mph and rpm values must be met before the trans will shift, you can be off 2 mph and the car will bang the rev limiter on a shift. this becomes difficult when something like N2O is used because it adds rpm/stall speed to the torque converter and the mph has to be adjusted and/ or the rev limit to compensate or it won't shift on the N2O but will be fine on motor.

with tires spinning at that rate it could be the opposite, the mph parameter is met but the rpm is not met yet/ since there is very little load on the motor and the stall speed is lower.. if that makes sense haha. being at the rev limit and not meeting the shift parameters could cause the trans to react like it does? like a safety function i assume? with the motor and trans under load it seems to shift fine, which is probably how it was tuned (with traction).

i assume MB uses something similar in their programming, as far as how the tcu tells the trans to shift.. if anybody cares to comment i am interested on how MB does it.

 

just emailed craig at bip, see what he thinks on the matter. if i need a tcu tune than it is what it is.. buying a modified car can be frustrating so i planned for some hiccups, hopefully this one is easily righted.

 

an update

i got the tcu tuned by BIP, got rid of the renntech tune in there. i didn't get too much of a chance to drive it as it is STILL cold and crappy here in pa but when i did drive it the issue seems to be resolved.

bfg drag radials were also added but it still spins through first and second if they are not hot, and it didn't go to neutral.

 

Good for you, that's what I was going to recommend. My car just ate a transmission after the same symptoms you described and for safety's sake I removed the EC TCU tune and had BIP do their TCU tune and it drives 100% better now.

 

i was at atco last night, car /transmission performed flawlessly! i did some monster burnouts out of the water box, the trans shifted great and never missed a beat.

buckhead performance did a really good job and the cutomer service was phenominal. bip will be hearing from me again.

it went a best of 11.52 @ 121mph. i couldn't get the 60' below a 1.7x with a best of 1.72. the car hooked it just wouldn't leave any harder. i was putting a little load on the drivetrain to avoid breakage (maybe stalled to 900rpms) and stomping on the gas. again mods are renntech pulley, renntech headers, h/e.

 

I'm glad Craig was able to fix it for you.

What a tool

 

I think I saw you at the track last night. Lemme know next time you head out there.

 

sounds good. you had the black cls with hoosiers right? badass car. there were a few e55's there too although i didn't see them run. mine is silver, carbon fiber lip and diffuser otherwise stock looking.

btw if you run in the lanes i was in they move the cone and you can line up in the groove not sure if you knew that or not. only if you have r comps/ slicks which you do, they keep the street tire cars out of the groove.

they used to do this, but i wasn't sure if they still did, so my first run i was in the street car lanes. the guy had the cone there to scoot me over, i motioned to move it and he didn't.. so i ran the side of it over i told him i have drag radials and to move it please haha. he did and then he told me to go in lanes 3 and 4

 

Glad to worked out for you brotha. Let me know when you are ready to let her dip into the 10s

 

I def will. I am thinking upper pulley, injectors, torque converter for the next round of mods.. Don't think it'll get me in the 10's but maybe close

 

I would go with a 82mm t/b or 90mm t/b first before a upper pulley imo. That and injectors will get you close with perfect track conditions.