Why is my Kenne bell Vette so slow

[brian vette]

Got it guys . It is parked for now. Will go to get it tuned this Sunday and post tune and scan and dyno. Thanks for the help


Brian

[Blown99]

Ok, I will throw my 2 cents worth in here.

I have a Kenny Bell running on a stroked LS2 at 402 CI, its running 8PSi with 9.6 CR.

No knock, no ping

3:15 rear gears an a l460E tranny. (See my post from this morning)

The car runs great. Low 11 in quarter and 17mpg combined.

Only 2 problems. It has so much torque during the automatic downshift from overdrive to 2nd gear when you nail it from cruise that it blows out the sprag grear in the tranny. (3 times now at $2000 a pop). An second, it goes through sepentine belts link crazy. If I run the rpm up above 4000, the belt will run off the idler pulley by one rib. The car will continue on like there is nothing wrong for 30 to 80 miles. Then the constant use of the belt without that rib will cause the rib to start to fray from the rest of the belt. When this happens, the frayed part gets caught under the rest of the belt and causes it to completely jump of the pulley. I will drive till I get home or to a place I can fix it and get out my trusty 15mm box in wrench, cut the frayed part from the belt and put it back on. Replace it again when I have time over the weekend. I keep a couple of spares.

I am fixing this problem (I hope for Good) by having a new pulley made that has shoulders on the two outside ribs that are 1/4 of an inch taller than the stock one so maybe it will keep the belt on the pulley.

Then the tranny problem I currently have a work around for. Just do not nail the throttle when the tranny is in cruise mode. Manually pull tranny down to second gear before hitting the throttle. The tranny guy also told me to do all hard launches from a stop using 2nd gear instead of automatic or from manual 1st gear. In this transmission, he says when you manually put the selector in 2nd, the tranny uses 4 more cluches.

As far as the IAT you see on your KB charger. I have the same problem. I currently have my car tuned for a good AFR at 180 IAT. I don't like this, and I am going to move my IAT sensor to the incoming air tube just before the TB. The location that KB moves it to is in the plenum of the intake. But I have taken the plenum apart and found out that the aluminum in that area of the plenum is very thick. Over half the sensor is recessed into a small hole which causes a tremendous amount of heat transfer from the heads through the aluminum of the plenum to the sensor. Even on a day of 45 deg outside temp, after a 20 minute drive, the IAT reports 170. On a hot day, I have seen it as high as 205.

If you are interested, I can post my tune, But I would HIGHLY recommend you get a 2 bar map and the Wide band. Its the only way to tune.

Blown99

[ls1x2]

I feel bad for the OP with all of these problems, but it sure makes me happy that I decided against the KB blower. I was VERY close to ordering it.

It sounds to me like meth is mandatory on these setups.

[Blown99]

Meth is not mandatory in my opinon. The IAT reading is correct for where the sensor is located. It is basicaly running at engine cooling temp because of the heat tranfer from the heads into the plenum of the blower.

[hiperf454]

I have a maggie on mine and it shows high iat and MAP. I just went from the 3.5 to the 3.0 and its making between 9-10lbs of boost. The milage is still good. Very little KR except when I dog it around in 6th gear. I have a wide band and 42lbs injectors. I can post my scan and my tune tonight. Im at work being productive..... I took the beginners coarse and worked my way up. I reset the LTFT and things got better quick. Do I need a 2 bar Map? I ordered one in and then did not go get it becase everyone said dud you need it. Is this true?
Regards
Kelly

[copley87blazer]

Hey blown99 On my th350 with a 243 gear or something close, i would kill the 2nd gear just like you, but I only have a 3 speed switched to a 355 and have had no issues since, when you are in second what do you rev it out too. Sorry dont mean to hijack thread.