Is it safe to spray in 5th gear at WOT at above 3500 rpms? (3.89 gears)

 

Not really. That is a lot of load on the engine. If you sprayed 1-4, then went into fifth at 5K rpm or then the load is less, just cruising along and going w.o.t. and spraying at 3.5K is gonna be hard on the engine. I've got an auto. so I could'nt say for sure how your tranny will deal with that either, probably wont like it.

 

I dont see no difference in spraying in 4th and 5th. If i may ask y are you needing to spray in 5th? a 1/4 mile you should end in 4th.

 

Well say I'm running a Cobra. I run of of 4th gear at around 120 I think. I've raced cobras before to 145. I can beat a stock cobra no problem but if I get a modded one on the line I might need to use the juice.

 

If you do spray to the top of 5th, PLEASE get video!

 

Ya if you spray to the top of 5th you better have 2 10lb bottles back there . ^^ what he said have some video of this please bc at the top of 5th you will be at like 170+

 

ive sprayed my car in 5th...once... if anything ill max out 4th and call it a day. i'll never go into 5th drag racing the car(1320) so i dont see a need. the car is going an easy 140+ maxin out 4th its plenty fast.

 

Dude you live on an island. Your in the ocean if you hit 140+ j/k Just looking for info in case there arrises a need.

 

I've always sprayed 5th since I need 5th in the quarter mile and on highway pulls. Just make sure your tune is solid.

 

I have sprayed 5th to 170 ish before heh heh

 

I have sprayed a 150 shot in 5th and shut down at 5500 rpm. all i have is a 10lb bottle and a heater.. all you need!

 

With a 3.89 gear i dont think he be at like 170+ correct me if im wrong but i just dont see him reaching that speed with that high of a gear.

 

i was wandering the same thing because i have 3.89's w/27" tires. on motor i go through the traps @ 6100/121mph and i'm gonna hit it with a 200 i can spin it to 7k easy though.

 

after my H/C swap i took a buddie for a ride and i hit the rev limiter in 5th did the math on a 6800rpm and 26in tire with a .74 OD for 5th it was right at 183 with a 3.89 gear so its possible. man was that fast and dumb i forgot i installed a plug in two of my sidewalls. i never did tell my buddie.

but before the H/C i did spray in 5th to about 160 and called it good.

oh yeah a 27 at 7000 in 5th you would see 195.5 ish
here is the formula
(rear gear ratio*MPH*TRANNY RATIO / divided by tire height* 336)=engine speed
so 3.89*195*.74/27*336=6985.40266666 there ya go


do the same for your trap its super close i did yours just leave out the .74 and 122 was 5900 rpm i did 122 cause its averaged you tach maybe off

 

People run the top speed miles spraying, people have done it on here. Ask PatrickG I think his name is, he lists it in his sig what mph he reached in a mile. It was around 180ish...