Heads or not?

**huitt06** · 10-19-2014, 08:46 AM

Newly purchased a 99 a4 TA. Currently has kooks headers,ls6 intake, and 373 gears. Car will be weekend warrior street mostly but occasional track use. Any cam suggestions and if heads is worth doing for the $? Thanks for any advice

**pajeff02** · 10-19-2014, 09:34 AM

Honest answer -- before throwing any money at the engine, make sure the suspension, rear and transmission can handle it. Tubular suspension components, an upgraded rear and a beefed up transmission will allow you to then build the engine without having to worry about "what is going to break next?" Our own car as an example -- all stock engine, but with exhaust, 12 bolt rear, UMI suspension, a Performabuilt transmission and 3,200 stall converter currently runs 12.4 - 12.6 at the track. Tossing on heads and a cam will easily dip me into the mid to high 11's with no worries of breakage.

**kingls1** · 10-19-2014, 03:05 PM

I agree with Jeff on this as I made my first track appearance yesturday. As my car has a lot of bolt on stuff my focus now is finishing up suspension up grades hopefully getting a new rear end next spring. I have a m6 and worried all day the rear would let go as it seems awful rough on it speed shifting and spinning through 3rd gear. Ran 13.4 and probably went in the 12's with Jeff's slicks but more than likely would have left the gears all over the track at some point. So a rear, brake upgrade, and shocks all before anymore power for me.

**huitt06** · 10-19-2014, 07:23 PM

Thanks guys for the help

**scott5** · 10-19-2014, 07:45 PM

What's occasional track use? I have a few cars including mine that have got by with the 10bolt. That go to the track once and a while but mainly street. If you rarely go then what you have will serve you. I don't advise putting money into the 10bolt besides gears, but I have been low 10s at 130ish with upgraded internals and a stock tranny with a 3600 stall.

What is your budget?

Goals for the car? Hp?

**huitt06** · 10-20-2014, 05:17 AM

Closest track is over 2 hours away....I normally go 2 - 3 times a year....mostly just want a fast street car...budget.. hmmmm....5 - 10k as a start, but I know the mod bug is a continuous process

**scott5** · 10-20-2014, 05:41 AM

5 - 10k will get you an awesome heads and cam setup. My suggestion would be to get with Brian Tooley and have him massage you a set of trickflow 220 as cast heads and a cam from him as well. The purchase a 92/92 setup and sell your current ls6 intake. Then you will have about 6k left over for your supporting mods and any thing else you would wanna do. I put down 486 through a stalled auto and 10bolt with that setup but I used a 102/102 and not the 92/92

**kingls1** · 10-20-2014, 01:07 PM

I know in my case with the general mods I have I was spinning 1st thru 3rd on street tires. I feel I could have run much better times if I could have put the power to the ground. That's where a stronger rear, track tires will play a huge part in having a fun track day with out having to worrie about the drive home as I had a 2 1/2hr ride home.

**scott5** · 10-20-2014, 01:26 PM

If you have 10k do it all

**huitt06** · 10-20-2014, 02:26 PM

Haha I dont yet... .how much price difference heads ?

**35th-ANV-SS** · 10-20-2014, 02:30 PM

As some others have already mentioned, it will be dependent on what your primary goal is. I have 540rwhp and am running a Moser 9" and about all supporting mods you can get; sub-frame connectors, built T56, PST drive shaft, drive shaft safety loop, LCA's, LCA relocation brackets, torque arm, PHB, shocks/springs, clutch, and tires. Nitto 555R DR did OK for about 10K miles. I will now be running a M/T ET Street.

I, too, opted to build the car to handle power prior to adding any power. The shock to the 10-bolt is a lot less severe with an A4 as it would be with an M6. With that said, a lot of people get "lucky" and run the 10-bolt without issues. Others aren't so lucky. It is really a matter of time before it grenades in my opinion and what it takes out with it when it does could be costly.

A used 10-bolt goes anywhere from $100-$400, depending on miles; generally around $250ish. However, if you have the budget, upgrading the rear-end to a 12-bolt or 9" would be your best choice.

**kingls1** · 10-20-2014, 03:01 PM

Originally Posted by huitt06

Haha I dont yet... .how much price difference heads ?

As most people don't and have to chip away peice by peice. My point was to build reliability before power. Try reading this also
http://www.ls1.com/forums/f66/here-l...uick-car-1844/

**35th-ANV-SS** · 10-20-2014, 03:02 PM

I worked with Bob at EPP quite a bit when I first started to mod my car. Pretty much followed that list to a tee and haven't had an issue yet (knock on wood).

**scott5** · 10-21-2014, 06:44 AM

If car is going to track where the shock would happen Alot then yes a rear upgrade is essential but if only going 4 times a year max and it spends 99% of its time driving around on the street the money can be spent other areas is all I'm saying. And I have seen 9in break as well. Nothing will NOT break. Nothing is invincible. I have seen 700rwhp stock ls1s last for thousands of miles and there have been brand new built engines blow up after 100 miles. It's all in luck when it comes to building cars

My 10bolt has a good center section, Moser axles and a good set of gears. It's been 1.5s and 10.2s at 13x and my last car went 1.4s 11.1 at 119 on a bone stock 130k mile 10 bolt with stock 3.23s leaving the line on a 125 shot. Both with 3600 stalls both with et street radials. With you being an auto the ball game is a little different than the 6 speed guys. t

This indeed is my opinion and based it off personal experience. I keep 10bolts as long as I can behind autos and it's the first thing I change behind 6speed cars. No harm in putting it in now but with you being 99% street car what are you going to use more? Launching at the track or power to use when you wanna play and roll around on the streets.

**pajeff02** · 10-21-2014, 09:36 AM

^^ Adding to this - wheel hop will kill a rear rather quickly. Having upgraded suspension components and correct geometry will go a long way towards keeping a rear alive.

**35th-ANV-SS** · 10-21-2014, 09:56 AM

With more power you have less traction. HP/TQ doesn't mean much if you aren't effectively putting it all to the ground. If the plan is to run street tires and just spin your tires with every throttle blip then the 10 bolt will last the life of the car probably lol. But, if you are running a great suspension setup with sticky tires, it changes things some, even on the street. More power = more stress on parts, period. Again, a 10 bolt could very well last a long time. Maybe it won't though. It's a crap shoot.

I personally wouldn't want to be the one in a car going 100+ mph when my stock rear end grenades, or a stock driveshaft twists and comes through your floorboard. I've seen both and no thanks.

Comparing a 9", 12-bolt or Dana S60 to a GM 10-bolt really isn't comparing apples to apples. Many more 10-bolts implode than all the other aftermarket rear ends combined. The likelihood of his setup blowing up any of these rear ends is extremely low.

***SMWS6TA*** · 10-21-2014, 11:57 AM

^^

My buddy 2 wks ago took my old 10 bolt because he blew his out with DR's and a MS3 cam, through a Turbo350 trans and 241 heads with stock suspension.

I wouldn't trust a 10 bolts in a Prius.

**scott5** · 10-22-2014, 05:41 AM

And I have personally seen a Moser 9 in break in a cam only 402rwhp setup. And one of my close friends went through 2 strange 12 bolts.

I'm not disagreeing or comparing, just stating ALL parts can and will break. Im not saying it is not a good thing to buy one but there are other parts of the car that can be upgraded before the rear end if he is not racing the car but four times a year. That's like putting in a cage on a car faster than 11.49 when you only go to the track 4 times.

But good luck with the car OP