I've run some times at the track...
for the first time out, I was pleased.

But my mph sucked.

What all can be holding my mph back...

mods and stuff are in my website

http://zboss86.cz28.com/

 

Tuning, horsepower, and weight.

Tuning is critical. I see from your site that your combo is mismatched.

What did you run?

 

what seems to mismatched to you...
I can take constructive critisizm, I'll listen to suggestions...

 

Your rear gear, TB size, tires.

Have you taken the time to tune the car on a dyno or at the track?

You don't have alot of details on your site. For example, you can make up for the lack of gear with a shorter sidewall tire, assuming you aren't already running 26 inchers, but I wouldn't know what size you were running from the site.

I ain't nowhere near being an expert, but at least you can learn from everybody's and mine's experiences both good and bad.

I threw about $6 grand at my old 83Z, only to run 13.50 @ 102. My combo was mismatched, and I'm only realizing it now which is like 4-5 years later.

You still didn't answer the question, what did you run?
What is the race weight of the car?

 

Those are the factors I figured you'd say.

I've only been to the track once to tune and that was with a 2800 stall converter.

This is an 1/8th mile track. That's about all I run.
Best I ran was 8.55 @ 83.4mph on 275 R15 50 Nitto's full 1/8th mile. 1.84 60' 3480lb with me in it.

My gear is a 3.23 "stock".
I'd like to change to a 3.42 when I build my rearend, this depends on what size tire I plan on running.
If I run a tall tire I'll probably run 3.73.

Throttle body, yes needs to be changed. That's $300 option thats going into a stronger rear first.
I'm just not sure how much the throttle body is restricting me...

I'm keeping in mind that I'm running on drag radials not slicks so I'm taking away some gear. Atleast till I get some suspension work.

appreciate the comments

 

8.55 @ 83 is nothing to be ashamed about. Tuning will get you better times and more mph.

I went from 82 to 85 mph in the 1/8 just finding out that I had too much initial timing, and the computer was pulling out 15 degrees retard. That's why I mentioned tuning. Just by turning my distributor back and retarding my initial timing, I picked up roughly 30 hp, or 3 mph. I had to run 4 gallons of race gas, and experiment with a knock sensor circuit trick to find out what was going on after about 5-6 passes down the track.

The 1.84 60 ft is my best time with nittos. I just couldn't hook with them with a stock suspension. That's why I mentioned gear and suspension.

Find somebody to swap a 58mm TB with at the track one day and find out if that's costing you power or not. That's the best way to tell, and it won't cost you anything.

Did you spin on that 8.55 run?

 

I had a full tank of gas with about 150lb in the back...
It barked a couple of times but hooked pretty well. The weight is one thing that kills my mph. But with a hundred pounds less weight I was getting 2.01 60'. Spinning like hell.
The 406 is torquey even with the LT1 intake.


I'm not sure what you can do with your computer, but a buddy of mine found out that if you take 1-3 degrees of timing out of last few hundred rpms it gives you 1-2 mph.
He started at 5300 and took 1 degree, 5400 took 2 degrees out and so on... This is real easy using the Speed-pro computer.
Now I haven't proved this yet with mine, but he has with his combo and it's real similiar to mine.

I got a buddy with a 58 mm throttle body... I plan on doing that trial sometime.

 

One thing that jumped out to me about your set up is the Cherry Bomb glass pack in place of the converter. Depending if that particular glass pack necks down and has protruding perforations, you could pick up considerable power and mph by dropping the bomb and putting on a straight pipe.

Yep,, sounds like you need to do some suspension work. Get it right and you could do without the 150 pounds and a full tank of gas. Win / win there. Get the hook without the extra weight!

 

That's where I don't get how a lot of guys on this board want to build 'torquey' motors. On the track, all a lot of torque does is spin the tires, and on the street also.

I'm moving to a bigger cam in hopes of moving the torque peak higher so that I can at least hook up with some et streets.

I even bought a set of slicks. The drag radials and my stock suspension couldn't cut it. I have a friend who cut a 1.70 60 ft on nittos, but he had to feather the throttle on the launch.

I didn't put my car together to feather anything, especially the damn launch! I want to stand on the gas pedal like bin laden's face is down there.

I always run with a 1/4 tank of gas.

Try running a 1/4 tank and borrowing somebody's slicks for a pass and see what happens.

 

We tried it a while back with out the cherrybomb, without the backpressure it gives you alot of popping. Now it's down to a nice little rumble.
yeah, suspension just has to wait it's turn. I agree it is next in line though...

I believe in torque motors. Build motors for torque, horspower will follow.
Honestly, for stock suspension it doesn't spinn that bad. I got a 400 so I could have the power and still keep it mild. The car doesn't lope at all.
It should be a fairly reliable setup. And after alittle tuning I hope to be getting 19mpg. My buddy is getting 21-23 on the interstate, with the setup but he seems to have more luck than me.

 

Uh,,, no way should you “need” more back pressure than what your single 3” Flowmaster exhaust with all the bends and turns the 3rd gens gives you. Trust me,, that’s more than enough (to much) back pressure on it’s own for your combination. I’ve built similar combos using true dual 3” exhaust systems (pretty straight also), and seen as much as .15 seconds difference just between turndowns and tailpipes over the axles and out the rear.

Sounds like you may like the reduced noise the glass pack gives you in series with the Flowmaster? I’m not sure when you reference popping if you mean the over all sound, or when you were in it full throttle. If it’s full throttle, you need to tune that thing in, be it by adding more fuel and/or less timing, without the glass pack in place. If it’s a sound issue, find a muffler that sounds good to you and replace the one you have with it. Regardless from a performance standpoint, that glass-pack needs to go. Especially if the thing necks down and has protruding perforations.