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How much PSI up front?

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Slowpoke70

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Discussion starter · #1 ·
Alright guys, the speed bug bit me, even though my car is slow, lol. I won't be heading back to the track for a couple weeks but i'd like to get some work done on the car before i return in hopes for better times.

Last thursday i noticed my air pressure was a little low up front, so i pumped the tires up to 36PSI because i heard if you have more air up front it's less rolling resistance.

What i'd like to know is how much PSI can i pump into a 35PSI tire (245/60/14 BFG Radial TAs) and still run safely on the street? It's about a 30 minute drive to the track on relatively decent roads.

How much is too much?

(70 Malibu, SBC, All steel, disc brakes.)
 
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#2 ·
It's not uncommon to see autocross guys using 40-45 psi.... they don't drive it much on the street before the race like that though.
 
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#3 ·
if i was u i would just get one of those little air up things u get at walmart and that plugs into ur cig. lighter and carry a air gauge with you and when u drive around on the street keep it about 32 or 35 and when u get to the track then air um up to 38 or 40 PSI :cool: and also im not for sure but i think u can let a little air out of ur back tires so it gets more traction
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:D
 
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#5 ·
I always thought it was dangerous to over inflate your tires...being that by stretching the radial outside its limits, it would break. That happened to me on my 65 stang...I was reading the tire wrong and kept inflating the tires to, I think it was 45-50psi. Then sometime later I ended up with balls/bulges on my tires which ended causing the tire to fall apart. I also thought that you'd only benifit from over inflating your front tires only when you're running skinnes. At least that's what I was told. And as far as the rear tires, when using street tires, isn't it not recommended you deflate the tire at the track, because it'll do the opposite of a drag radial or slick would do?
 
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Discussion starter · #7 ·
Well, Maybe i'll try out my bro's 165/15s the next time i'm out there and go over about 5lbs. The only problem i see is swapping tires at the track, seems like a pain in the behind.

Hey Alexis, you clean your engine bay yet? LOL, jk. Those spin-techs sounded sweet man, i like your ride. All the more reason for me to build that stroker small block someday soon.
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#8 ·
Originally posted by Slowpoke70:
Hey Alexis, you clean your engine bay yet? LOL, jk. Those spin-techs sounded sweet man, i like your ride. All the more reason for me to build that stroker small block someday soon.
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LOL, not yet. It's a definite must do!!! I gotta hit up my buddy, the one who I told you installed my tranny cooler, to see if I can take my car over there so we can clean it up. He's got a pressure hose, I just gotta buy some Gunk, and I'm set! You'll have your ride up and running before you know it. Believe me! It felt like years were gonna go by before my Velle was up and running, then before I knew it, it was time to hit the streets
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Discussion starter · #9 ·
Haha, mine runs just fine, just not fast enough, lol. At least it is a half second quicker than it was with the 305. I think before i know it i'll have the stroker in there tho, but i want to learn how to optimize a combo with this not so great 355 so i can have an idea of what it takes to tune an engine. Then i won't have much trouble with the 383.

But on my to do list before the 383:

1. Get the car legal for the track.
2. Break into 9sec in the 1/8 with the 355.
3. Go as fast as i can with the parts i have now.
4. Try Performer intake (already have it from the 305)
5. Try RPM intake. (Will buy for 383 build)
6. Swap 305 heads onto my bro's 307.
7. Maybe cam swap in 307.

I need some more work under my belt before I tackle the 383 build.
 
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#10 ·
I run the M/T Sportsman fronts in size 26 x 7.50. On the street, I use 35 psi and at the track I like to set them at 42 to 45 lbs for less rolling resistance. On a short 1/4 mile run, heat buildup is not really a concern IMO, but on longer street drives, it could be.
 
#11 ·
Originally posted by Slowpoke70:
Haha, mine runs just fine, just not fast enough, lol. At least it is a half second quicker than it was with the 305. I think before i know it i'll have the stroker in there tho, but i want to learn how to optimize a combo with this not so great 355 so i can have an idea of what it takes to tune an engine. Then i won't have much trouble with the 383.

But on my to do list before the 383:

1. Get the car legal for the track.
2. Break into 9sec in the 1/8 with the 355.
3. Go as fast as i can with the parts i have now.
4. Try Performer intake (already have it from the 305)
5. Try RPM intake. (Will buy for 383 build)
6. Swap 305 heads onto my bro's 307.
7. Maybe cam swap in 307.

I need some more work under my belt before I tackle the 383 build.
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Bore and stroke that 307, bolt on an RPM intake, that 600cfm carb you got, and nice cam, either port those heads or get some new ones, and you're set
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Then u'd have urself a nice, sweet, kick a$$ motor that'll have the lil "umph" you need and save u $$$ on gas, cause you're gonna need it for that 383 ;) :D
 
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Discussion starter · #12 ·
Naw, the 307 isn't mine. It's my budies engine in my brother's car. My car has a stock-ish 350 in it. You can check my combo out farther down the page of on the next page, in my post "New Timeslips".
 
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#13 ·
Originally posted by Mr.McFast:
if i was u i would just get one of those little air up things u get at walmart and that plugs into ur cig. lighter and carry a air gauge with you and when u drive around on the street keep it about 32 or 35 and when u get to the track then air um up to 38 or 40 PSI
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That would work really well. I borrowed one of those things from a guy in the pits one night and was flat amazed at how good a job that little thingie did of airing up the tire in just a minte or two.

Yeah, don't drive it on the street overinflated, but put it over five or ten pounds on the strip, then deflate before you leave.
 
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Pat Kelley
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