I've had my 99 z28 M6 for over a year, and it's now time for an increase in performance.

I've been reading the "So you wanna be fast" thread and doing research of my own but I'm still a little lost. This is very new to me so any help will be appreciated.

Essentially I will be buying a new lid, headers, intake manifold, and throttle body all about the same time. Along with those, some 4.10s

First I would like to know if I'm off to a good start atleast. The car is stock minus flowmaster catback.

The exhaust will be true dual, which leads to my first questions. If I'm not mistaken there are three o2 sensors on the car, in what configuration do I set up the third o2 sensor behind the cat? Considering there will be no cat on the car after the exhaust is done.

I am going to buy the HP tuners software when I purchase my parts, perhaps my answer to the o2 sensors is in the tuning?

I know there is a lot of opinions as to what is better then what, so go easy on me here... I know for lids, it's not that big of a deal, but for TB and intake, what would be a better decision. In the thread I was reading, 90mm is good, but is that what I am after is what I'm wondering. On Jegs I was looking at bbk 85mm TB and bbk 85mm intake manifold, anyone have any comments on that?

Along with Intake and TB I take it the MAF needs to be replaced with something larger as well?

I know the car should be built to my driving style, it's not my only source of transportation, but by far my favorite. I drive about 15 miles on the freeway for commuting a few times a week, and a lot more around town. I'm not looking to make a race car, but simply something more fun to drive. Any comments, wisdom, or any help of any sort will be GREATLY appreciated. Please include links for parts if you have suggestions. Thank you!

 

There are 4 O2 sensors. 2 are before the cats and 2 after. 2 on each side.

If you go catless, you'll need just the 2 sensors that are before the cats.

You won't need a larger MAF for what you're saying you want to do and you won't need to spend the cash on a BBK TB either, just get your stock TB ported and polished and it will be fine. I like the BBK intake, I'm thinking of getting one myself.

IIRC, the stock MAF is good for just over 450HP before it becomes a restriction.

Personally, I would save the money from the TB and MAF you wanted to spend on and buy a FAST 90 intake.

Just my opinion though.


EDIT: You might also find a used FAST 90 for cheaper.

 

Thank you for your quick response.

So only using the 2 o2 sensors, that will still throw a code right? But the HP Tuner can eliminate that issue I take it. As mentioned earlier, passing smog is not my concern. Basically this build was brought on by a family member.

I bought my z28 March of 2011. I wanted an SS of course, but couldn't find one for the budget range I was in. 2 days ago my younger brother got a 98 ss m6 for 4700. It ran okay, but not any faster then my car when we brought it home. That night we found the plug wire on cyl 3 was broken. It came alive, it's some what built, has a mild cam in it at the very least, but is noticeably quicker then my z28 of course.

Well younger brother, quicker car, can't let that slide. So basically I'm trying to level the playing field. My father grew up working on cars, some based on performance. I do believe he just talked me in to putting a slightly more aggressive cam in my car now as well. Looking forward to more advice and help along the way, thank you to all who respond!

 

Yea, you will get the SES light but you can tune that out. After I installed my headers and ORY, my SES light came on also. I lost the cats, AIR and EGR too. My car runs rich now, but I haven't had it tuned yet.

If you're gonna go through the trouble of putting in a cam, you might as well do it right and put something more aggressive and gain more HP to go along with your other mods.

One major thing you'll have to consider though is the rear end. It more than likely won't hold up to a non stock powered LS1, especially on the M6.

My brother broke his doing a burnout and his SS was a completely stock A4.

 

Start with the basics. Get a lid, any kind, and long tube headers. Ditch the AIR and EGR emmiosions systems. Don't forget most true dual systems are LOUD, so be prepared for that. I just went with a regular Y-pipe set-up and run a magnaflow quad tip cat-back. If you want a beefy intake the fast 90 is a good one, but seeing u have a 99, an ls6 intake is also an upgrade, and only costs about $300.

If you are talking drag racing speed, a drag radial will help a lot! But here is the flip side. As the other poster mentioned the rear will then become the weak spot with a sticky tire. I just installed a new s60 in my car because i blew my 10 bolt. I killed it on the 1st run of the night. Problem with a rear end is though they cost upwards of $2500... so its no cheap upgrade. I went with 4.10 gears on mine now too. Speaking of 4.10 gears, i would not put those in your stock 10 bolt, it will just end up being a waste of money.

 

I happen to be fortunate enough to live very close to a retired GM engineer and experienced racer. He claims that the throttle body doesn't become a restriction until well over 500 HP. According to him the Ls6 manifold is the best investment if your not running huge boost numbers via forced induction or a high RPM race motor at which opint a fast 90/90 or 102 become a better alternative.

+1 on the long-tubes and MIL eliminators or you can have them turned to constant ready state with HPtuners or EFI live.

+1 also for the suggestion on not throwing money at the stock 10 bolt. It will defiantly grenade behind an M6 car making more power then stock. Better to save your money and buy a 9 inch, s60, or a 12 bolt when it does. My suggestion is always the 9 inch...

+

 

I know the 10 bolt is weak, and would prefer a 9 inch over about anything else. I can pick a used 9 inch up relatively cheap, but what should I look for? I know it's going to take some modification to fit in my car, luckily my father having the background he has, I have access to a torch, wire feed, and plasma cutter. How hard is it to take a 9 inch out of another car and make it fit in the camaro? What would be a likely junkyard candidate for the donation?

And in an honest answer, how much better is the fast 90 intake vs the bbk? After seeing the cost of one, some numbers to compare it to would be handy if anyone has them available.

Btw, my 10 bolt... isn't the same one I had in it when I bought it. Living proof of their reputation.

I'm not going to do the heads on the car yet, that will be later this year I hope. So with an aggressive cam ( As far as streetable goes in my book, if it runs, it's streetable), headers, true dual exhaust ( loud doesn't bother me, my neighbors are use to it) intake whether it be bbk or FAST 90, and possibly the 85mm BBK TB, idealistically what kind of power gain am I looking at? I will be purchasing HP Tuners FIRST, my speedo is WAY off and that damned skip shift light is incredibly annoying, so I will need to learn how to effectively tune my car.

Thank everyone again for the help, looking forward to this project and the wisdom of LS1 Tech.

 

Just remember when you get a cam, you will have to upgrade the valve springs to handle the lift. IIRC, anything over .600 will require better springs, trunion upgrade or better rockers, and push rods. You also have to take into consideration PTVC.

Skip shift can be tuned out. I don't know much about the rear end. Someone else will be able to give you a good answer on that. I'm curious about it myself for my car.

The BBK vs FAST vs LS6. From what I can recall, the BBK is good for about 5hp over the LS6 and the FAST is good for about 10 - 20hp over the BBK. I'm not 100% sure on those numbers though because I've seen a few different results but I know it's pretty close.

 

Found this thread about BBK, I know theres tons of threads about the two, but like the OP most of them are going to aggresive cam,,,,Not to hijack but I have a stock 00 ws6 and a tune shop is offering me a used BBK(not sure if its80-85mm and a ported&polished stock TB for $375, should I grab it or get the ls6 ? I dont want to coin for the FAST(high dollar) the only thing I want to add is LT non-catted ORY-exhaust, and 1-2 later years add ls6 heads-street cam(228r or Torqer V2 or 3. My question is will I be ok with the BBK and P&P throttle body with that set-up with and/or without the head/cam pack? Im not going aggresive and dont want to go any futher. IE pistons,engine porting,etc. Just H/C/I and supporting mods like timing chain and so forth my DD

00 ws6 Bone stock M6 -I have the slp lid thats it
sorry to hijack just want to know
Thanks
Im working with $2000. and lucky my dad owns a car repair shop so ill only be buying the parts with free install

 

Kujo-
If you don't want to spend the coin for the FAST, I would go with the BBK over the LS6, what the shop is offering you is a good deal. You will be fine with that intake even with the head/cam packages you are looking at. Since you're on a budget, I would look into the BBK LT/ORY combo. The combo is IMHO the best deal out there, and the coin you save will help you put on a much nicer catback. Fitment is second to none and they work amazing. You can get them at the WS6Store, which is where I got mine (I picked the chrome ones, they still look great even over a yr later). Then just pick a nice catback (Magnaflow is what I run, Borla, Corsa, and GMMG are great ones too), and some O2 extensions for the fronts and you should be all set as far as exhaust goes. While you are doing the LTs, I would also look into a nice set of motor mounts just to be on the safe side.

Sorry for hijacking to answer the question!

 

THIEVES! Just kidding. Anyone have information on the 9 inch, and possibly a measurement of the stock 10 bolt so I have something to compare to?

 

A quick search brought up a decent thread on that

https://ls1tech.com/forums/new-ls1-o...lt-9-inch.html

 

I appreciate the info and the link, some good reading in there. My problem is though, I don't want to spend a couple grand on a 9 inch ready for my car. I would much rather pull a 9 inch from a ford in a wrecking yard, and install it myself with custom brackets and such. I'm wondering what a likely candidate for the rear end would be though. What is the width of the 10 bolt, and what would the closest stock ford vehicle with a 9 inch be?

 

Don't worry about the 10 bolt until your pushen on the higher side of 400hp...At the track with slicks every other weekend...or it just breaks.
I've been abusing my 10 bolt for 4 years without any issues. You could buy all the mods you listed for the price of a 9". Don't fix what's not broke...but be prepared for when it does. I would've been pissed buying a 12 or 9 yrs ago not knowing I could've still been slamming my 10 bolt for 4+yrs..

 

I won't be seeing the track for a long time if ever. Building my car more for street play. Not looking for the higher side of 400, but 400 sounds nice. Thank you for the info.

 

Sorry to hijack your thread mattbm, I just dont want to start a fresh thread
Im hijacking again lol

But heres the story.....
Friday night went to the local race spot and..........
I know this has been beatin to death about the HEAT SOAK and theres tons of threads about it and dyno results and back and forth arguein between members....
But I live in St Louis and there is a cruise spot and ran into a few trans am guys and we talked , I brought up the fact that I can get a bbk cheap. 1 of the guys said he had a bbk and it had shown better hp gains over the ls6 when COLD,,he dyno it cold and then hot ,he said when it was hot(warmed up) he lost 12hp, I showed him the graph that I found on ls1tech about the bbk showing better results over the ls6 and he said its because it was not heated up yet, He went back to telling me after a few street races he drove to the dyno place and it dropped the 12hp (he showed me on the dyno sheet he had with him), He has then switched back to the ls6 and did the same racing (did a few races then dynod) and it was still above the hp reading of the bbk hot, Now im getting the fact that maybe I should just get the ls6 and say the hell with it.... Im tired of reading forums after forums about the bbk vs ls6 and I am about ready to just not touch anything on the car lol

P.S I have a stock 00 trans am ws6 --He had a 99z28 ls6 intake mid lenth headers and weight reduction and he beat me by 5-7 car lengths is that about right?, or was he hiding other mods,, he showed me on a weight sheet he lost 245 pounds outta his car.
I am a good driver because he said other stockers he races are alot farther back he said I kept up with him pretty good

Sorry to hijack justdont want to start a whole new thread about this
if I dont hear anything back I guess I will start a fresh thread asking about this
Thanks,

 

Doesn't bother me any, I'm looking for free advice, why bother someone else about it??

I'm by no means a mechanic, so hopefully some one else has some input here, because I'm on the same boat. I don't like the idea of the money, but maybe I will just go fast 90 and not worry any longer. Might as well fork over the extra cash, can't take it with you!

 

BBK heat soaking is a complete myth and BS, period.
Even if it wasn't I could give you ten reason why it doesn't matter.

It has been an ongoing topic for years, the ones in the "know" say BS... Others rant and rave you will lose 20484 Rwhp from heat soak.

Go with whichever intake you can get cheaper IMO, I wouldn't pay 20+$ more towards either one of the intakes... Other than that, jump to a FAST.

 

BBK(not sure if its80-85mm and a ported&polished stock TB for $375

I would jump on this IMO.. Sell your TB for 40-50$ and your intake for 40-50$ and you have a nice gain for under 300$.

 

If you don't get that deal on the BBK I have the intake and a few throttle bodies in stock and can beat mail order prices