Yellow Bullet Forums banner

1 - 17 of 17 Posts

·
Registered
Joined
·
1,155 Posts
Discussion Starter #1
This weekend had a MSD chip go bad for the air shifter, and before i could get to the shifter, it hit high side chip while on the bottle. Didnt seem to hurt anything, but is there anything i should check in particular? I dont want to go out and next race and tear anything up.
 

·
Super Moderator
Joined
·
12,128 Posts
I would just do an overall check on the condition of the engine.. The rev limiter seems to effect each application in a different way.. I have seen times where a three stage deal can hit the rev limit and now damage, and I've seen times where a single stage cars has hit the rev limit and killed the pistons and rings.. I would consider a compression, leak and last would be just to run it and see if you still have good vac and all dy plugs... SJ
 

·
Registered
Joined
·
6,825 Posts
x2 what Steve said, + valve lash & maybe even valve springs unless they are very new...
 

·
Registered
Joined
·
1,155 Posts
Discussion Starter #6 (Edited)
i was able to hit in high gear right as it was starting to hit it. but yes, a compression test will happen tonight. Also, it didnt ever smoke and we ran the motor for about 10 minutes straight and everything still sounded great, and plugs look great as well. I think i got lucky, but i wanted to know from others what i needed to check before i go racing again in 2 weeks. Also, i am using a 7al3 and i believe it was the chip because when i got back to the trailer i changed to a 3k chip and the ram worked perfectly. I use the box for the shifter. Do i need to send the box back and have it checked just in case it wasnt a faulty chip? Does anybody know what the ohms should be for a 7400 chip?
 

·
Registered
Joined
·
243 Posts
I have hit the high side rev limiter on two occasions and both times I got a head gasket,the gasket blew between the cylinders.I have also hit the rev limiter when a planetary gave up and had no damage at all,so you may get lucky and have no damage, I think as long as you just bumped the limiter and not layed on it you will be ok. Jmo
 

·
Registered
Joined
·
1,508 Posts
Hate to admit this, but we had a "programming mishap" (read as: we phucked up) when we downloaded into our 7531 box. Set a "dot" at 5500 rpm to take away a touch before the converter grabbed the engine, but didn't move to another dot so we basically set a 5500 limit for the high side. We were running 1/8 mi. at the time. The car left hard and then never really pulled, the driver (yeah, me) pulled high gear and it just didn't accelerate. I think we ran a 5.20 or something like that. That was with two units, 36 / 30. Never hurt a thing on that lap. Just realized how stupid we were! Ran fine the rest of the weekend.

Sometimes you get lucky. Good luck.

Paul
 

·
Registered
Joined
·
1,800 Posts
I was on it at 8400 for .4 seconds when the converter bolts sheared off a the finish line. seized up one lifter and scuffed that cam lobe. Other than that no damage.
 

·
ProStock Jackstand Winner
Joined
·
25,123 Posts
I left the line at 6500 on the two step and unit... lol it was an accident, but didn't hurt anything.

But, when I broke the transmission, it hit the rev limiter for .2 seconds and like Shane said, when I pulled the engine apart, the head gaskets on both sides started burning through in between the cylinders. Never blew the head gaskets, but the next pass would have done it.
 

·
Registered
Joined
·
1,553 Posts
I was on it at 8400 for .4 seconds when the converter bolts sheared off a the finish line. seized up one lifter and scuffed that cam lobe. Other than that no damage.
I turn mine that hard when its on a normal pass!!
Hit the rev limtier(8700) at the southerns when i left the air bottle off and didn't hurt anything.
 

·
Registered
Joined
·
487 Posts
On this subject- I am a newbie to N2O- what RPM spread do you have between when you shut off the nitrous and the rev limiter or do you not use a window switch on the nitrous?
 

·
Registered
Joined
·
6,825 Posts
No window switch. N20 on for entire run. Shift @ 7500. Top end rev limiter at 8000-8200. Cross at 7600.
 

·
Registered
Joined
·
1,553 Posts
On this subject- I am a newbie to N2O- what RPM spread do you have between when you shut off the nitrous and the rev limiter or do you not use a window switch on the nitrous?

I don't have a window switch but I would imagine 200-300 rpms before the rev limiter
 
1 - 17 of 17 Posts
Top