My goal for this summer is to run a high 14. Last summer I ran a 16.4 @ 89.4 with a really hot car, a slipping clutch, a terrible 60' times (3.0x average). At the time I had Open element, accel wires, LS1 driveshaft, flowtech headers and y-pipe, cat free, air pump free, 180º thermostat, complete 2.5" exhaust with generic muffler, 1/4 tank of 87 octane on 225/60/16 Goodyear Eagle II.

Since then I have added Summit wires, LS1 front brakes, LT1 fans, Mac Subframe connectors, wonderbar, and some basic chip tuning.

Will 3.42's, auburn posi, pbr brakes, BFG KDWS 245/50/16 (or other similar tire), a stage 2 clutch (CF or similar), a high flow fuel pump (if I can get to it without cutting the exhaust or the car) , mastering launching a manual, and more WOT chip tuning get me in the 14's? Or is there something else I am missing? I am trying to do this with stock engine cause eventually it will get upgraded as a whole.

 

get a good pair of heads and and a better cam....then will talk

 

You could be close if you get the tuning dead on. Look at some tubular LCA's and panhard bar, maybe some other suspension stuff, then get an aftermarket intake too. But I don't think you'll hit 14's, especially with the Flowtechs and 2.5" exhaust.

 

The posi, tires, brakes suspension mods that you've already done (or plan to do) aren't going to help you --- you had a 3.0 sec 60' time and that's not the fault of the rear end, suspension, chassis or tires --- it's the driver. Some of those things can help the launch, but your problem isn't fixing those items -- it's fixing your launch technique with the manual trans. i.e. even the stock tire/suspension could get you to 2.2 60' times if you had the launch skill, and 0.8 sec improvement at 60' is like 1.6 sec improvement at the finish line.

Your mph is decent, so you have a shot at high 15s and low 14s, but you need to work on the launch and fix the clutch (as you already said).

You also said you ran those times when the engine was hot (in the summer). Do you really think an open element is helping, when you are pulling heated underhood air into the engine? The open element is only a help if the stock air filter, or any other possible replacement filter assembly, is a restriction to airflow. And remember that your engine is fairly stock, so it's not pulling massive cfms of air..... so you don't have the same filtering requirements as a 400 fwhp engine would. Less hp means less airflow means which means you don't necessarily need a perimeter-open air filter.

IOW if you can DIY a cold air setup (filter, plumbing) that's not restrictive, then it will work better than the open element --- because the air is colder and therefore denser. So IMO you are losing a few tenths by using the louder-but-slower open element.

Said differently, for two air filter designs that have the same flow restriction, which one allows more engine power: the open or the "cold-air" type? HINT: one will sound louder but make less power.

Of all the other stuff you listed, I think you definitely need a fuel pump replacement because 89+ mph in a 305 3rdgen implies 230+ fwhp and that's pushing the limits of the stock pump. I don't know how much more you can gain from tuning because I don't know how good/bad your present tune is.

I'd also suggest the "ultimate TBI" mod by rounding the airhorn on the TBI upper body. It should improve airflow by a few pecent, and it's "free".

 

traction, traction, traction! Do whatever you can to get your car down to a 2.00 or lower 60' and your on your way. Your single 2.5" exhaust and generic muffler may also pose a pretty big restriction depending on what type of muffler it is. Will it be enough to get you into the 14's? I dunno. I wouldn't worry about air induction at the moment you have much bigger fish to fry. I really think the type of pre TBI inducting you run is overated. No need to go chasing around 5 to 10 hp when you have 20 to 30 locked up in your exhaust and cam.

If I were you I wouldn't worry about 14's till you get the basics worked out. Get the gears and posi in there and go to the track till you get good enough to get consitant runs in. You'll have a much better idea of what your combo is capable of, and then you can set realistic goals. 14's maybe realistic, maybe not.

 

I know a lot of the time problems lie on me. It was my first time running at the track, and I got hustled around waiting to run and the engine got to about 228º (or whenever the factory fan kicks on) in 80º weather. I'll just need a lot of track time to get comfortable.

I have also before I replaced my slave cylinder, which I believe to be part of the slipping clutch problem. (Heat from the heaters had made the clutch fluid worthless.)

I should be changing the rear out in the next couple of weeks and I'm planning on doing the fuel pump then. Does anyone know if the rear is completely out of the way, can you remove the tank without removing the exhaust? I can post pictures of the exhaust routing if that would help (its basically stock).

Also I have been searching and haven't come up with a direct solution to my fuel pump quest. If I am looking for a multi-port volume/ pressure pump, that is dimensionally the same for connections, and is reasonably priced (>$100), what should I get? I don't want to be hacking or modifying any of the pieces just plug and play setup, and no overkill 255 that will tear out my tbi diaphragm. .

 

I'm sure that if you search the TBI and TPI threads here, you will find several fuel pump options, including the factory GM fuel pump used on 230-240 fwhp L98 Fcars (which would be plug and play) and/or the pumps used to feed the 275-285 fwhp LT1 Fcars. Those pumps are more than enough for what you have.

 

A 190 lph walbro will do the trick. A 255 won't tear out your diaphram. The diaphram is on the return side of the regulator which means if there isn't any restriction in the return line then it won't see ANY pressure. If you do have a restriction in the return line then you'll have all kinds of problems. Some people have said that they couldn't get their pressure down to stock with the 255, but I have no first hand experience with that. If your burning your own chips, it might be a good idea to go ahead and get the 255 and set the FP up where everything is happy and tune from there, that way you won't have to worry about running out of fuel once you get a little further along in mods.

As for getting the tank out, my friend did it by just unhooking the rear hanger on the exhaust and letting it hang without pulling the whole thing. If you have the whole rear out that should help alot.

As for driving, don't worry about it, you have to start some where. I'm guessing you have 2.73's in it now. That makes launching a real trip. There's such a narrow window between wheel spin and bogging. The 3.42's should make it a bit easier. Practice on some slick pavement till you get good at it, then when you get to the track all you have to do is sneak up on your launch.

 

A 16.4 with those mods?

I honestly would have expected mid 15's.


But yes, take a look at the LT1 Cam Threads here:
https://www.thirdgen.org/techbb2/sho...92#post2185792
https://www.thirdgen.org/techbb2/sho...hreadid=262466

Those two threads alone, if read over and over, should make you understand everything you need and is probably one of the best mods you can do to a TBI. However, along with that, you DEFINITELY need to burn a new Chip for your car, your car will not adjust to the new cam and/or heads you put on.

 

That 16.4 doesn't mean anything, with a 3.0 60' those runs were worthless. I've run a 18.2 and backed it up with a 13.9. The only difference was the fact that I didn't blow the tires off for the first 1/8 mile.

 

Check my sig for my mods, I trapped at 95 mph which is good for mid 14's and that was completely untuned with a ****ty clutch.

 

[QUOTE]Originally posted by Gladstoneiroc
[B]I know a lot of the time problems lie on me. It was my first time running at the track, and I got hustled around waiting to run and the engine got to about 228º (or whenever the factory fan kicks on) in 80º weather.
[QUOTE]

Have you also looked into wiring in a direct control fan switch to help with this. You could have the fan on anytime you want. It's a simple mod that would help keep those temps down.

 

[QUOTE]Originally posted by DM91RS
[B][QUOTE]Originally posted by Gladstoneiroc
I know a lot of the time problems lie on me. It was my first time running at the track, and I got hustled around waiting to run and the engine got to about 228º (or whenever the factory fan kicks on) in 80º weather.

Quote:

Have you also looked into wiring in a direct control fan switch to help with this. You could have the fan on anytime you want. It's a simple mod that would help keep those temps down.

Done last weekend

 

Kool..now do what I need to do....work on traction

 

14's shoudl eb pretty easy with teh gears. you already ran enough trap speed to run a 14, jsut work on getting it out of the hole better.
when you do your chip tuning don't leave out throttle transitions either. remember, you are at part throttle when you launch and you ramp to WOT. making that space in between work for you can be a huge help to your short times.
you are definately ready for the timeslip, just a little tweeaking and a few practice launches away. good luck

later
tim

 

Yous should be able to get into high 14s without doing anything more than what you've discussed EXCEPT getting the chip tuning right. That sounds so simple, but it's actually quite complicated and absolutely critical to getting your car running right. check my sig, it has my mods and times. i've done that without any chip tuning. that's next and i'm certain i'll break into the 14s with no more changes except tuning.

before you make more changes, learn to tune and burn chips or find someone who is good at it to do it for you. every change you make takes that stock tune further from optimal; you'll see decreasing return on your mods with each one you make till you're able to tune for each one.

 

I've gotten in the chip burning. Its a lot peppier with just advancing the timing 4º and changing the WOT tables. I'm sure I can go with more timing cause I'm not getting knock on accel, just decel for some reason. I need to get a bunch of WOT runs and have the expects take a glance at them.

 

You really need a WB for the WOT. I actualy got mine fairly close over months and months of work with logging the NB, and a g-tech. But was able to nail it in 20minutes with a wideband.

 

I know a WB would make my job incredibly easier. I just want to try and get all my WOT to around .9v on the NB and then later work from there.

 

That is how I started, then I started messing with the Gtech, and I ended up changing from there, with the wideband tuned WOT, my NB voltage goes from .700 - a dead 1v. but the WB stays right at 12.8 the whole way. The stock sensor can't even really get you close.

If you don't have a wideband, shooting for .850mv or so, may be a good way to start, but you will never be happy with its performance until you hook up the WB.

 

TonyC
you hit 14's on nitrous? what size motor and what shot?

 

His sig says its a 90 shot.

Actualy, I think TonyC and I are actualy racing to see who can get the 12 second time slip on the spray. I think I have the advantage, all I need is traction!

I did 14.5 NA with a cam, intake, exaust, and gears. not much else was done mechanicly, just lots of tuning. I'm even running the stock heads still.

 

I actually ran a 14.91@93 off the bottle and a 14.3 @101 on a 90 shot (spinning pretty bad on shifts and running fairly rich. I could knock another 3 or 4 tenths off the nitrous time and prolly a tenth off the N/A time just by learning to drive . I'm shooting for what Dewey's doing, 14.5's or better off the bottle on the stock heads and TBI and 12's on a ~120-135 shot. Unfortunately he's got a little bigger cam and intake than I do

 

are both of you guys 5.0's?

 

Yes.

My goal is to hit 12's on this combo, and 14.0 NA.

Then the next motor goes in. That should be a 10sec combo!

 

Dewey are you keeping stock heads?

 

depends. I have a set of 416's, that just needs to get to the machine shop for screw-ins, and guides cut. Judging by the power curve from the dyno, and what the cams powerband should be. I'm guessing heads, and a 2" TBI unit, would be good for 40hp-50hp, that and some traction would easily get me 13's NA. My traps currently are good for probably14.0-14.1, and 12.7-12.8, but I had no traction at all at the track last time. I think a set of DR's may be in my future.

I'm trying to not put money into this motor though, as I'm building up a twin-supercharged 327.