dsadsdaiouser

We are in Louisiana this weekend at the last Super Chevy event of the year. Our C5 is a cam only with bolt-ons and makes 429 to the wheels. We also have a Nitrous Outlet kit with a stand alone , NANO kit and all the bells and whistles. It will make 600 on 150 jets.

Tonight we ran 11.33 @ 119 with a 1.53 60' NA. When I try to spray it, even with the progressive controller set to come on 2 seconds after I leave, it still bangs the Rev limiter in each gear all the way through the run. Is our Yank SS4000 too loose for the nitrous ?

Scott

Fishmasterdan

Had the same issue but different brand TC I took mine out and had it tightened up.

00SlvrSS

4000 is a little loose. Do you look it in second when the spray hits?

tug686spd

iTrader: (11)

Its possible your bolwing through the converter some but probably not enought to worry about once tune is adjusted. My guess is the nitrous is loosening up the converter 2-300rpm and is allowing the motor to hit the rev limiter before the shift mph is met. When I set up my trans tune I usuall set my shift mph 3mph slower than the equivalent mph for my shift rpm. I then set my rev limiter 200 rpm above the shift rpm. Doing it this way allows you to notice a slipping trans as soon as it starts going instead of completely frying the trans right away.

If you have the capabilities I'd drop the the shift mph and rpm and log a couple runs to get the tune right then you'll be able to see if the converter is holding or not. If you have a log and want to compare efficiency let me know and I can post up mine with the SS4000.

dsadsdaiouser

Sent you a PM.

dsadsdaiouser

Can I ask what your stall was and what you had it tightened to? How did it affect your NA times? And after you put it back in you didn't have any nitrous run problems? Did you need to get your car retuned for the new lower stall speed?

Thanks.

Scott

shortdog

iTrader: (1)

Sprayed well over a 200 shot with my SS4000 w/o an issue, but my tranny has been rebuilt.

Like Tug686 stated, get your tune adjusted by moving the rev limiter up 3-400+ rpms past your shift points.

Is your tranny stock?

dsadsdaiouser

Transmission is stock. Do you think it is slipping?

IIRC the shift points are set around 6200 and the rev limiter is 6900 so it's already about 700 rpm above the shift points.

I spoke with Dave at Yank yesterday and he said for this converter to work with what I'm doing the car would have to pull to 7400+ rpms. He suggested having the stall redone to 3400 and felt that would wake the car up on nitrous.

Scott

kinglt-1

iTrader: (26)

Give Greg @ FTI shout. They have a 3800 nitrous converter that works good NA and is great on Nitrous. I think the 3400 will leave quite a bit on the table NA if you are concerned with that.

dsadsdaiouser

Thanks. Speaking with Dave at Yank he said the same thing. We're now running 11.30s NA with 1.50 60' times and he said a 3400 will slow the ETs down about 3 tenths and the 60' down about a tenth.

This sounds weird but we actually want to do that. Before the cam when we were bolt-on only the car ran about 11.60. I've been racing for 30+ years but my wife is new to drag racing and likes to drive the car too. I don't want her going low-11s @ 119 and prefer to slow it back down to upper 11s @ 115 and will feel much more comfortable.

Scott

shortdog

iTrader: (1)

Sounds like your tranny is slipping and can't handle that size shot.

Dave @ yank is right regarding shifting higher to benefit for that size stall on the shot, but I wouldn't do that until you get a beefier tranny. I'm shifting at around 7K.

dsadsdaiouser

I think I'm going to have my 4000 restalled to 3400. Hard to tell if the loose converter was the issue and/or a slipping transmission. Might just try the converter first since that is a relatively inexpensive fix and if it still slips pull it back out and have the transmission built.

Scott

LIL SS

iTrader: (9)

With my 2-step set at 3,600 my verter flashes to 4,600 NA (475rwhp) and 6,200 on my N20 (750rwhp).

Whats the verter stall to NA?
Where do you shift the car?