camarokev400

Allright guys ive hit a wall i cant do anything to go any faster....... my best time so far was a 13.5 at 102.36 mph and that was with a .845 reaction time, 1.969 60 foot.

Now here are the car specs. Its a 406 small block, it has about 9 to 1 compression or less with .30 cc dish pistons, stock 350 64cc heads drilled with steam holes, edelbrock performer eps intake, 750 edelbrock heads, and a comp cams extreme energy 268 grind (477/480 lift and 224/230 duration@.50), stock rocker arms, and accell ignition, timing is somewhere around 10degres.

Tranny: worked th350, B&M shift kit, uprgraded clutches, B&M 2500 holeshot torque converter.

Rear end: 3.42 NON POSI

Totally stock suspension

16 inch rims with 255/60 (goodyear eagle RSA's)


Is there anything other than getting posi and maybe a ram air setup that would help me get into the low 13's or maybe high 12's i know some new heads would do it but is there anything cheaper i am over looking? (by the way i tried some old drag radials and they didnt work, they killed my gear ratio ran 13.7 with them.

AlkyIROC

A base timing of 10 degrees means nothing since that's only at idle. How much total timing does it have? Typically it should be in the 34-38* range but every car is different.

What kind of fuel are you using?
Have you played with the jets and read the spark plugs yet to see how much fuel it's burning?
How much does the car with driver weigh?
Are the valve springs still original?
Is the carb a VC or DP?

There aren't too many cheap ways to make power if everything is set up and tuned properly.

Expensive ways include, More cam, more carb, bigger valves and port work to the heads. A dual plane intake is fine for the street but that one runs out of power at 5500. The cam you have is good to 5800.

Your 255/60/16 tires are 28" tall. I can't see how some drag radials killed your gearing since you already have some tall tires. Maybe you need some 26" tall tires but since you're already below 2.0 60' times, you shouldn't need them.

NOS will put you in the 12's. Even a detuned 50 hp shot should do it. You don't always need to use a full 100-150 hp shot.

camarokev400

Good points..... I am running 92 octane gas, and i dont know about the tires other than they are 15 inch isteand of my usual 16 inch tires.. dont know exactly what size they are, i will have to check(they are just some cheap M&H's that are almost wore out prob about 20 years old) i just know that without the drag radials i was running 102 and was turning like 4600 at the line and with the drag radials i was only at about 4200 at 99mph, i think it is the top end that is killing me... not positive though just from the numbers on my slips. I am not sure about the total timing? ill have to check. But about the valve springs yes they are stock only because with the the stiffer comp cams one's that i had i was messing up all my pushrods, its a long story but i have had no trouble with the stock ones sicne i really dont turn that many rpms. As for whether it is running lean or rich...... it smells like it is running really rich but the plugs have white tips? and the carb is a Edelbrock Performer 750cfm with mechanical secondaries, it has smaller jets and metering rods in it not sure exactly which ones....(to lean it out). As for the weight i am not exactly sure how much the car weights... it has no AC equiptment left, no spare tire, and all emissions ripped out so i am guessing 3300 or more... i only wiegh 150 so somehwere around 3400? How much would i expect to gain from a posi rearend?

camarokev400

Oh yeah... what about my headers and exhaust setup? I am running hedman shorty headers pretty tiny ones they are just the cheap 100 dollar ones from summit, and i have there y pipe which is only 2.5 inch so i have a single 2.5 inch pipe going back to about where the converter use to be and then it goes into a 3 inch flowmaster americna thunder catback.... would some long tubes and some dumps before the rearend gain me much?

five7kid

iTrader: (14)

That tiny y-pipe is killing you. You're committing the same sin the factory committed with the 400 - not letting it breath. Long-tubes would help, but getting the y-pipe opened up to 3" where the two pipes come together, then all the way back, would do wonders.

Performer carbs aren't mechanical secondaries (as commonly defined). They have an air valve like the Carter AFB and q-jet before them. The air flow through the secondaries is controlled by the air valve, not the throttle plates. You should be able to handle a bigger carb, like a Holley 800 DP.

RBMZ28

I can't stress this enough.......The 400's need to breath. And those heads are holding you back more than you can imagine.

camarokev400

yeah i know the heads arent helping me at all, but i really dont want to fork out the cash for some new ones, so im looking for some stuff to get me in the low 13s but i would really like to be in the high 12's. What kind of exhaust setup would you guys reccomend? I was thinking some hooker long tubes, going right into 3 inch pipes that dump before the rear axle with some type of low profile muffler so i wont bottom out. Something like this picture.

camarokev400

Any other little tricks i can try to lower the ET? I have heard prob almost all of them like remove your swaybar in the front, up the PSI in the front tires, lower the rear tire PSI, ice the intake and on and on.... Any suspension mods prob really wont help me much... right? since i am already at a 1.9 60ft time with a totally stock suspension and some cheap tires.

IHI

iTrader: (1)

Clear up 1 thing in case you did'nt already know-R/T has NOTHING to do with your ET or MPH-very common misconception!!! Running a lower octane fuel should help also since your compression is on the low side, lower octane puts out more BTU than the higher octane fuels, and with your low compression, it's basically overkill with the 92. Try it, might not make a difference, but worth a try. Roller rockers will help too.
As far as suspension mods, all last season it was factory with 120K+ miles and 1.8's were every pass once I settled on a combination, stickies of course are a no brainer. This season the only change to the drivetrain was removing the PW steering and factory water pump and replacing with manual box and electric pump. Just those 2 mods for my set-up netted a .6 gain. Suspension wise I bought some Spohn tubular LCA along with the relocation brackets. 60' times did not change initally until I got the motor happy again with some tuning. This past weekend the 60' times were all in the 1.76-.79 depending on the air, but I was not really sold on these bolt on suspension peices for my situation, and had I had to buy them new for what they sell for, I would have been sick since the price to gain ratio was not worth it for me, not saying they won't help a radial tired car over factory, but with my stickies, traction is not an issue with my guttless power plant. Personally depending on your $$$ situation, exhaust would be the first place to start since it's cheap and will help with whatever mods you throw at it. Heads are a factor with any motor along with cam, but so goes the price hike as well. They would be something definately on the to do list for the future when you can swing it. Any place you can alieveate weight would be a plus as well, but that all comes down to personal preference as to what we all decide we can live live with/without. 1 other thing you may consider is porting your heads you have for some extra flow, and replacing the current head gasket with a copper gasket to get your compression ratio a little higher as it'll rasie the static rate anywhere from .3-.6 and then you can warrant the high octane fuel for kicks, but still would not be necessary. Upgrading to a better/bigger carb would also help ya. Holley's are my brand of choice for ease of tuning and parts availablity since almost all racers at our track run Holley's, but my little 355 running a 750 Holley VS ran a best of 14.10 early last season, got a hold of a Holley 830DP that the guy drilled out the squirters and instantly ran 13.6 just carb swapping. So for race applications or go fast applications in general, take all those formulas and throw them out the window. Last year a buddy bought a new 950HP that got thrown on about 10 different engines from a 327 to 454 and the least gain documented was .3 from the carbs the guys had. Now the 950 has a reputation of guys NOT wanting to try it, since all the fellas that ran 'er last season ended up buying one, so that speaks volumes in my book. I have'nt tried it yet casue I have other things I want right now and I know what'll happen if I did try it.

88gta400

My thoughts exactly, I dont think exhaust is going to help much with restrictive heads!

camarojoe

Are you running a hyd. flat-tappet cam? If so this going to cost power over a roller cam, especially compared to a solid-roller. Your heads are the other the big problem, probably the biggest problem. You see an easy 100hp is you change these two things. You'd gain 30hp from just going to a hydraulic roller, with a little less dur. and a lot more lift. It'd help out big time with your idle quality too. Also what is your cams intake center line? 406's run best with tighter ones like 106degs.

camarojoe

I forgot to say this, but geez, if you'd just put some AFR's on that engine you'd probably see a full sec drop off your 1/4 time. I'd put money on the fact that'd you see mid 12's!

MrDude_1

id not do anything.

save up your money.

then spend it on somthing worthwild...


btw, that dual exaust you posted will take away most of your ground clearance..... would suck for a daily driver...

if you want longtubes, look in the exhaust forum on that sticky for the install thread... theres some pics of the longtubes into a y pipe that goes into a catback..... looks like it leaves pretty good groundclearance...

D Stroy H8

Hey, you could get some thin cut head gaskets and that'll bump the compression up a few tenths. Thats cheap. That exhaust is killing you tho. I think you might see a half sec. gain just by making the exhaust 406 worthy!