Tall tires?
 

right now i am having porblems with my mustang. i have a high horse power mustang. with big rear gears, and the original c4. i expected cruising speeds to be around 60 mph with about 3,000 rpm. but it does 50 at 3,000 rpms. I have not ran it down at the track, because it feels like the trans needs a forth gear. but i was told that i could put taller tires on the car. how tall can i go? right now i have on the back P235/60r15 and yes they do fit. if you can help i will be delighted

hey whats up.. sound like you have the identical setup as i do. yeah i had the same problem .. i go 60-65 at 4000rpm!. its crazy but 60 to 80 is really fast. anyway i had a big lift in the back so i could fit 275 60 15's. they are nice and good traction. what would be ironic was if your car was pacific blue pearl metallic. lol :-)

are you saying that you raised the back end? how much did you raise it? where did you get the equipment? i am kinda making it into a drag car, but also a street rod. well the color of my stang is a biege. but it is a nice color. i am working on a 65 pacific blue car now!

Get yourself a set of John Calvert's Caltracks. www.calvertracing.com and you won't have to worry about traction, but I would not lift the back end up. With that gearing you are kinda stuck with the size tire you have now and the RPM it is spinning. I run a 28 inch MT Sportsman on my 65 FB and a 28 inch tall slick at the track, but it is really close. As far as ET's, I would not be concerned about running to many times. Unless you have box welded the spring perches and back braced the rear end housing, and are running 31 spline axles in a 9 inch, if youre HP estimate is right, it will tear all that out on your 1st pass anyway. If you are not running hardened parts in that C4 it will also go by the wayside. Unless you are running a trannie shield, flexplate shield (or a JW Ultrabell) and all SFI parts, I would not risk losing my legs, untill all that was in place with a stock C4.

I'm not trying be negative, just want you to be safe..

Ron

two words.

5 speed.

hahahaha. a five speed would be great. and i am thinking about it. but thanks about the tips from ron. i don't want to lose my legs! i have been thinking and i have for got about safety. alli have is the 5 point harness, roll cage coming soon. there are no ford guys around where i live, they are all old chevy guys and raise hell when i go bye them on the track! i will have to try the 28 in tiers hope they work!

So you have had the car to the track with the new setup? I thought you said no ET's yet...what did it run with the new setup?
I run a Wilson Manifolds plate sytem, single stage, 150 horse shot on a 347. The chassis is NHRA Certified. Right now it is running 9.70's at 137 on a ten inch tire.
The coupe like yours ran 12.00 at 118 on an 8.5 inch x 26 inch slick, with a 5 speed. Broke everything on the coupe and all because of HP, 8 inch rear end, the auburn, the gears, the drive line, spun the housing around the spring perches...the trans got really sloppy...

So just be careful..

ron

well,
i have not had it on the track, i just get into in on the street. well i am kinda stuck with the 8", the last car that i have been working on was a 66 gt 350 clone drag car with an 8"in rear. it held up threw the years. i want to put an 9"in but i need money.

Ok I'm starting a pool on how long the stock block lasts

My money is on 6 passes.

blownbyyou , what's your motor combo?

ok.....I just reread all of the posts

I find is laughable and quite disturbing that you would even consider running that much hp with the stock C4 and 8" rear-end.

Your gonna break ****.:)

hahahaha.
yea i am over excited and bouth a high performance engine and just threw it in my stang, i knew that i had to do some trans work and rear work. but i need money! oh yea, i have soft ware on my comupter that allows my to blue print engine. how about a 302, with 530 hp with no power adders. i am thinking about building it. well just to let you know how reliable my stang has been. before i did the mods to the rear, i ran 8 times down a track in one day, blowing by my dad in his vett ( he sold it right after that). i did not have problems till i got it home, i broke the engine mounts and the engine ate my new 4 core radiator! and then i broke a few rocker arm studs and a few retainers! oh and i a new c4 is on the way!

A stock block can handle about 550 HP, unless you use the old spec racer trick and do a Cryo freeze. That, plus a main girdle should keep it safe to about 650 HP. Beyond that the R302 or the new Dart block. Software for "blueprinting" your engine...I am not sure what you mean by that and how that contributes to a gain in HP. For the stock classes running in the NHRA it is a key ingredient (clearances and casting numbers etc.), but for what you are doing it makes no sense at all, since all the clearances you set would definitely not be for running in a stock class. Can you explain?

Ron

i wanted to keep the car stock, but it needed to much work and money to keep it stock. so i guess i am building a street rod that can run some good e/t's. the software that i have is a c.a.t. program. it allows my to change parts on any engine and it gives me an estament on how much horse power to expect, (ex, i can swap 302 heads with stock 351 and it will tell me the expected horse power gain) it also allows me to do just about any thing to any engine, with out spending money. so i can tell people what mods they can do to a stock or not stock block to get the most out of it. thanks for telling me about the capabilities of the 302. i did not realize that they can take so much horse power. what is a Cryo freeze?

www.onecryo.com It is a process that tempers the metal and makes it harder. By some estimates by 5 point on the Rockwell hardness scale. You also might want to read this about what blueprinting is http://www.hastingsmfg.com/Service%2...ueprinting.htm

I think you might have something like Desktop Dyno or Dyno 2000.

Ron

The stock block is only good to about 450 hp.......500 with a main girdle.

Anything above 500hp is borrowed time, IMHO.

blownbyyou, what's your motor combo?

Just so we are clear...are we talking the block only or are we talking a short block? And yea, tireburner has a good question, what is your combo? Cam, heads, intake, carb...

Ron

i was thinking about putting a main girdle in, but i was not thinking about it when i put the engine in, to put on in the engine has to come out and fliped right? the software that i have is not the descktop dyno, it is a C.A.T. programe that i picked up from a meet. but i do have the desck top dyno.

No the engine stays put. Just drop the oil pan, install it (comes with all the hardware), put back the oil pan. Any news on the combo?

Ron

oops! sorry i forgot to answer your question! the engine block is a 302 H.O. block bored .40 over. forged sivolite pistons, and rods, 11.5:1 compression, 351w heads that have been ported and polished, crane cam exh lift .480/ int .520. performer RPM intake (going to be a victor j.r) holley 670 carb, duble pumper. 1.7:1 crane rocker arms, crane springs, headers, four core radiator, and 3" side pips, and oh man does it sound good, i can set off car alarms at idle in a parking lot. oh yea i will let you on a secerte, it only costed to do all this work about $2,500. and it was easy to do! i started when i was 14. i am 18 now.