190E 3.0-12v Turbo - Page 32 - PeachParts Mercedes-Benz Forum

Joreto · #**466** 07-15-2013, 11:01 AM

The car is finally back on the street. I've cover 300+ km. with the new setup, gearbox i holding up nicely and runs great. The new turbo setup is running fine, no oil leaks, no smoke but the problem is that with the current turbo the car has less power than with the previous one, even when fully spooled. Haven't played with the ignition timing yet but the mixture is tuned. I have no explanation for this power loss, this turbo has bigger wheels (both turbine and compressor), the turbine wheel is more "open" and with a larger A/R, with all this one would expect the car to make more power when fully spooled but this is not the case, guess I'll have to do some digging to find out what the problem is , any ideas are welcome ....

On another I swapped the rims to amg ones and mounted the original rear spoiler, here is how the car looks now .

oldsinner111 · #**467** 07-15-2013, 11:41 AM

maybe you'll need nitrous for 1st spool up.Does it make power once spooled?I've heard you can go to big sometimes.

Joreto · #**468** 07-15-2013, 12:00 PM

No and thats exactly the mistery, once spooled up it still makes less hp/nm for the same boost.

yzn · #**469** 07-15-2013, 12:48 PM

check for leaks on both intake and exhaust side

Joreto · #**470** 07-16-2013, 09:04 AM

No leaks found. I'm coming to the conclusion that the ignition timing must be optimized (haven't changed it yet) for this setup as it's very different from the one before. Plan is to play a bit with the timing this saturday/sunday and see what happens .

RBYCC · #**471** 07-16-2013, 09:44 AM

Quote:

Haven't played with the ignition timing yet but the mixture is tuned.

Not enough timing = less power.

On drag cars in the sixties, advancing or retarding timing was our primary way to adjust power to match track traction conditions.

If your AFR's are optimum then start adding timing until power falls off.

Ed A.

Joreto · #**472** 07-23-2013, 05:02 AM

Found the problem or part of it . Turns out the YZN was right, I have leaks in the exhaust header flanges (both turbo and engine), so I pulled the header and sent it to be resurfaced. Hopefully this Saturday/Sunday the car will be back on the road and I'll report back if the issue has been resolved .

Joreto · #**473** 09-10-2013, 03:02 AM

This saturday I tested the new setup at the open drag day and I'm not happy. I managed to run a 13.45 @ 178 km/h . With the new turbo the car has a smaller powerband which makes it slower (lag between shifts). This weekend I'm going to reinstall the old turbo charger and hopefully on the next drag day I'll finally get in the 12 secs.

With the old setup I was running 12.8-12.9 according to the gtech , with the current I'm running 13.6 - 13.7. Tested the gtech on the drag strip and it gives 0.2 sec slower times consistently ....

Old (red) vs new (black) hp/tq curve at @0.9 bar

pic from the drag event

whipplem104 · #**474** 09-10-2013, 08:36 AM

Honestly the curve on the new turbo does not look bad. You are down on power in the lower rpm range but if you do not short shift it you should be doing ok unless the turbo just stalls and there is bad lag. If the lag is bad you could flat shift it with an ignition cut. This combined with a good rpm on the launch should yield a better time.

Joreto · #**475** 09-10-2013, 10:06 AM

The problem is that from 1-st to 2-nd shift because of the gearbox the rpms go below 4500, 2-nd to 3-rd just above 4500 and thats where I lose time (rev limiter is 7100 don't know if its safe to rev to 7500, may try it). I'm thinking that with the old turbo and the optimizations on the exhaust header my power curve will look like the combination of both i.e. upto 5200 it'll be like the red line than above that it'll be like the black so it'll be optimal.

P.S. I analyzed the runs on the g-tech and with the old turbo the car had more hp/tq for more time in a given gear, thats why it was faster .

P.P.S. Forgot to mention that after the 7-th run a lost 1-st and 2-nd gear, it's not a big problem, the transmission pins have to be changed (bmw gearbox :-D ) .

Joreto · #**476** 09-17-2013, 08:32 AM

Opened the gearbox this weekend and it turned out that the shifter fork for 1-st and 2-nd had broken, I have already got a replacement from a donоr box, I also swapped back the old turbo.

some pics ot the internals of this box

eduardocastrejon · #**477** 09-30-2013, 05:28 PM

JOreto:
Sorry to ear about you trans problems

I have the same problem
I already destroy the 717.411 gears , I replaced with a 717.430 2 that i destroyed second and third synchronizer (I hope) I bought the synchros maybe I can repair this one.
I prefer the 1 gear of the 430

I supose that getrag is not a solution, I want a tremec 3550-3650 join to my new lsd diff.
Please let me know if you have a better solution
borwarner or tremec , I will need to adapt a lot of things

If i dont have to follow rules, I will go for a tremec t-56 that can handles 550 lb of torque
amg 3.6 to 717.430

Joreto · #**478** 10-02-2013, 12:06 PM

Hi, for now my solution is to use the BMW gearbox. A lot of high power cars use this box, as well as one of the fastest 2.3-16v turbo (running 9 secs. in the 1/4mile). I opted for this box since they can be found easily here and are cheap.