nebur8

iTrader: (6)

Can I install heads without a tune. I'm looking to buy a set of heads, no cam yet. For a 98 z28 A4, should i need a tune afterward or will i be good?

Thanks

slayerized6

iTrader: (12)

if it helps, i just got done with my ls6 head swap yesterday. havnt driven it too hard yet, but it idles fine. but i have an m6, you got an a4. you probably will need a tune because of the shift points.

nebur8

iTrader: (6)

Does that mean that heads will change where my car shifts or is it b/c i have to change my shift points to get more out of the heads?

eamador11

you would need a tune because the air/fuel ratio will be off. upgrading just heads is ok but not much of a mod because the stock cam can only let so much air in anyway. usually its cam only first then heads later not the other way around.

nebur8

iTrader: (6)

I'm aware of that, but why go through the tedious work of changing all the springs when I can buy a set of new heads with upgraded springs and throw the cam in later.

GMCtrk

iTrader: (23)

Im having big problems with my tune after putting heads on...VE table is way off....thing will not run good at WOT...6-7 degrees KR and very lean.

nebur8

iTrader: (6)

Did you install the heads before a cam swap?

bonestock99

iTrader: (1)

You will be fine. I installed cnc 317 heads and 04 zo6 cam in my buddies 99 t/a no tune with wideband and his a/f was good and car ran great...oh yeah he has lt's and a slp ram air. But as soon as you get a cam get a tune, his cam was only a stock zo6 cam not too much larger than stock.

GMCtrk

iTrader: (23)

yes. stock cam. stage 1 ls6's onto a lq9.

jmilz28

iTrader: (13)

You will need a tune. If you do heads only (which I actually think is a good idea for a DD), then I'd consider several options:
1. quality ported perimeter bolt heads (GTP or Advanced Induction)
2. ported 243s, bang for buck but you will need valve covers and coils switching to center bolt heads
3. AFRs - I'd mill them and have them ported, you'll still need the valve covers and coils. This is the most expensive option but will be the biggest kick too.

Sling a FAST combo on there and you'll smoke some cam only cars, taking them by surprise. Regardless, you will need a tune.

What is your budget?

jmilz28

iTrader: (13)

This is true too, plus you can leave a lot more **** connected doing heads only, saving some serious work.

99TransAmLS16Spd

iTrader: (8)

You should be fine without a tune with heads. Your idle will not change dramatically with just a head swap. Timing should be about the same, as timing is based around the cam profile as opposed to the heads. Remember, our cars use the MAF probably 95% of the time once your car is warm.
A tune would still be beneficial, especially if you're running on a stock tune because they tend to be so rich at WOT, but ultimately your MAF is there for you

Cobra R

iTrader: (6)

From experience:

2003 Z06, GM CNC/milled heads, bringing compression up to 11.2:1, Kooks headers, no cats, cold air intake. No tune work done at all, AFR was 12.8 at WOT, car ran 12.0@120mph on stock tires. Car ran 116mph stock. So picked up 40hp I would say is a fair estimate.

Would it of picked up more had it been tuned, I am sure it would. Was it a must? No not on my car, car ran without any problems.

jmilz28

iTrader: (13)

Your car probably had a rich factory tune (as many do) to be safe. Those of us in hotter climates, like TX and FL, have to be a little more careful than you Northern guys about leaning out/detonation.

OP: Even without a tune, it is likely it will run (very general statement) ok, especially at part throttle with light/moderate loads. Depending on how good your heads are (and the rest of the intake/exhaust tract) and how rich (or not) your factory tune is (especially spark and A/F tables), you may be good to go or really asking for detonation. $300-400 is cheap insurance to prevent that plus pick up more ponies and MPGs.

What other mods do you have?
LS6 intake?
Long tubes?
Cat-back?
Still have cats?
Lid?
Ported TB?
If you're already taking advantage of a rich factory tune, this may be an extra bad idea.

Further, the tune will optimize shift pressures, shift points, RPM limiter, eliminate torque management, etc., making the car run even harder. In reality, changing the heads MIGHT affect both idle and shift points or may not.

You are leaving out critical items:
1. BUDGET
2. Which heads are you getting?
3. Other mods
and others.

Without a tune, you may be OK, may not. I will say this with 100% certainty - No one here knows for sure what the outcome will be, though they all seem to think they do. Each one's experience (and car) is a little different. Without knowing all the above, we really can't even give it a good educated guess. If we knew ALL the answers above, your mods, had a good dyno sheet AND some recorded data, we could give you the answer which would approach 100% accuracy.

Regardless, the tune is not a smart place to try and save a few bucks. It's you car and your wallet, do what you want. Don't say you weren't told.