I'm planning to modify a stock '99 C5 without violating the CA emissons laws. I've heard the arguments of getting away with it, but I'm not willing to test my luck. I'm also committed to staying normally aspirated.

Given that, my plan is the following:

HP:
Blackwing intake + bridge
FAST 78mm intake manifold & required TB
AFR Mongoose heads (205cc)
Corsa pace car exhaust

Other:
HRE 547 wheels w/Michelin PS2 (295 rear, 275 front, 19/18)
Bilstein sport shocks
Lower 1"

Questions:
What HP gain will I get from the above?
Will I have to do an LS1 edit?
How much if I don't do the AFR heads?
How much more if I put on LT headers and press my luck?
What would improve handling better than my plan?
What else would you recommend that is legal?

Many thanks for taking the time to offer your advice. Happy New Year!

 

Magnuson Supercharger is about 8 or 9 grand installed with painted hood and passes california emissions standards..

Go that route. Really a low pressure blower and a very good way to go.

Don't bother with the heads if your not swapping the cam..

The intake manifold and the thottle body's a waste too..

Air filters worth about 15 hp...



The heads, the throttle body etc is just Not worth that much on a stock cam motor.

Good luck....and reconsider the magnuson supercharger.

It comes with a 200 dollar option that allows for 3 year /36 K mile driveline warranty.

You can't really beat that with a stick.

 

I don't think any of the mods you listed has a CARB #, so it would seem that by not wanting to violate Ca. emmisions, there is not much you can do.

 

Here are some baselines for you to chew on...

My 99C5 M6 was dyno'ed with the following mods first:

In May 2004 my car was dyno'ed with a Borla XR1 Catback system and Granitelli Cold air Intake, stock everything else... Made 296WHP and 301#ft. of torque.

February 2005 I bolted on a Z06 intake, Shaner Ported Tbody, LGM headers, SLP High Flow Cats, and a custom 3inch exhaust back to a pair of Borla Stingers. I did a LS1 Edit tune through Jeff Creech at Carolina Auto Masters and the car made 335WHP and 355#ft. torque.

In june I blew up my motor at VIR during a MazdaDrivers.com HPDE event. 2 Broke rods and a 3inch by 6inch hole in the block! Motor had 112K miles on it.

The new motor I isntalled in August has a thunder 224/224 cam kit, ported 1998 LS1 heads (HUge porting killed the port velocity) W/ 2.02/1.57 valves, and a complete forded bottom end, w/ ARP bolts. I Was still running a.. the mods from the February list above.

Car was tuned in November of this year back at Jeff's shop in North Carolina and made 375WHP and 370#ft. torque. The car should be making above 400WHP, but we suspect the heads are just killing the power.

This will give you a decent baseline, and others can chime in, but when we put the car on the rollers after installing headers and intake w/ 3inch exahust, it was running horribly rich. I think an LS1 Edit should be mandatory for anything other than a CAI and catback. You'll pick up a bunch more use-able midrange and your fuel mileage will increase, and drive-ability will increase as well.

I'd do a cam over the heads anyday of the week, and you might just be better off running the LS6 intake instead of the FAST. Not sure it is worth the added money, unless you're going with more cubic inches are a much bigger cam/ heads package.

Mike

 

Thanks to all those with suggestions. So far, it sounds like thumbs down on everything I planned due to a lack of a cam change.

So, here's the rub: I don't want to super/turbo charge. I don't want long-tube headers. I'd rather not swap cams unless there will be NO change in my idle, etc.

Is there any way to make real horsepower without doing those things??

FAST brags about gains. AFR brags about gains. They don't make stipulations about swapping cams nor adding headers. Are their claims false?

Thanks again.

 

224/224 550-560ish lift 114 lsa cam
LS6 intake manifold
blackwing, twin-flow, tric, whatever intake
LT headers (if you want to be N/A you really need these)
Comp 918 valve springs, or go ahead with the AFR-205s

Take it to andy (or mail order, that is a well known cam) for a good speed density tune, and you should be able to keep it stock idle.

Suspension: go with 04 Z06 shocks and sway bars (you will love this) and lower on stock bolts. Get the springs to if you can swing it.
4 wheel alignment when all is done.

That with new wheels and tires with more rubber, it will be like a whole new car.

I would give Andy at A&A a call, he would know best what works with those emissions standards.

Good Luck!

 

no false claims,but it is a given that if you are going to install freer flowing heads you would want to upgrade what allows the heads to flow then it is a given you would want to upgrade what helps the flow out.
ok,you don't want headers[LT'S]now you have 2 choices[shorties/ls6],save your money,neither one will give you what you want.
you like the fast intake,cool,bolt it on a stock motor,maybe you pick up 3 hp,because you are not using it to its full potential for a couple of reasons,1-stock exhaust manifolds,cats,h-pipe, are too restrictive.believe it or not,the exhaust helps the incoming charge into the cylinder by what is called scavengeing[on the exhaust stroke both valves are open at the same time as the piston is coming up.this is called "overlap"as the piston is pushing the exhaust gas out,that velocity is helping the intake charge in as the intake stroke is about to begin].if the exhaust can't scavenge the exhaust out efficiently your incoming charge is moot[it's like having a cold,all clogged up with no were to go].
you need to: a]before spending a dime.think about what you are looking for[like you are doing now].how much horsepower do you want?
b]remember HORSEPOWER COSTS MONEY AND BREAKS PARTS!so before doing anything factor that in
c]if you do a little at a time,that's fine,just have your goal set before hand
in my opinion,unless you are willing not to worry about the emissions,don't do anything.FWIW,my Z06[03],the things i've done are CAI,carbon fiber air bridge[more for looks than anything],LGM pro longtubes,random cats[relocated to the rear,not behind the headers].O2 simms[no rear o2's],B&B bullets, LS1-edited,car picked up like 35-40 hp at the wheels and will pass inspection[all i/m's are set and will pass the sniffer as long as the cats are fired.
just my.02

 

your post doesn't (nor your bio) mention what tranny your C5 has. But if it's a 6 speed manual, then one mod you can do that's hidden from the smog police would be rear gears. (since there is no reprog needed with manual trans C5's).

.

 

I think you have some bad info on the comment about cams. If you get a 114LSA moderate lift and medium duration cam, the tune will be fine. My Thunder Racing 224/224 cam idles like stock and soungs like stock.

If you're hung up on the fast intake, then great, do it. Won't hurt. But if you had to do one or the other, I'd do a cam over heads. But I wouldn't do heads without doing a cam. You won't be able to take advantage of the freer flowing and better port velocity without the lift and duration changes of the cam. You need to talk to a reputable tuner in California and seek their guidance because it sounds like you don't have a good understanding of the components and how they work to get you the performance you want.

Also, long tube headers are generally good for 25HP and 30#ft. Torque at the wheels. That is a hard gain not to consider. Talk to a tuner, as I'm sure there are guys on this board from California running my exact combo and are smog legal. In Virginia we have to deal with the smog police as well and I pass with my tune. None of the aftermarket parts are Carb certified, but otherwise, I pass the sniffer test.

Mike

 

Are you moving to California? Your sig says Connecticut. Whole different set of rules as I understand.

 

1.K&N has a cold air box that is CARB legal.
2. Shorty headers. They make CARB legal ones.
3.LS6 intake.
4. AFR heads. CARB legal.
5. Dyno tune.

That would all be smog legal.
Now if you want to take chances, then go with LT headers and a cam.

Steve

 

Wovreen, I'm in CA and have built up no less than 5 LS1's that wanted the same thing you want. Everything you listed is fine if those are the items you want however since you are going to go with the AFR heads I would suggest a 220-224 CAM on a 114+2 LSA. It will idle very close to stock and really wake the car up. In addition to that I would put on some CARB approved shorty headers so that the heads can breath. The best part is that it will still easily pass smog sniffer and the visual test. If you change the exhaust keep your factory cat and only modify from the cats back. Again this will keep you well into the safe zone.

 

I just finished my first 6 months of mods on my 6sp '99. I think the results are great and make a difference in how the car sounds and feels. It is definitely quicker and I can now hang the tail out whenever I want. I do not have any dyno numbers but trust me the car is much quicker. Either that or it just sounds so good I just hit the pedal more often.

1. Bassani Catbacks and x-pipe. ($925 installed)
2. Blackwing intake ($234 ebay)
3. Lingenfilter Polished TB($110)
4. Z06 intake manifold($372)
5. Z51 sway bars($75)
6. B&B Shorties ($350)
7. Bilsteins ($300)

I had the mufflers installed at Carlisle and the other parts I installed myself. The car runs stronger and is a bit louder than stock but has little resonance. This is important to me because I do a lot of long distance driving and like to speak to the other person in the car. LT's and H/C bring a whole new level of sound aka noise. And all the mods are CARB certified. For about $2600 I think these mods are an excellent upgrade.

To go to H/C setup looks like $4,000 when all is said and done(double roller sprocket, cam, springs, retainers, ported oil pump, heads, professional installation & tune). Add LT's and high flow cats and the price jumps to around $6,000 on top of the mods listed above.

I may very well go to the HC setup but I'll wait until after the winter to decide. I guess it all depends on how quick you want to drive and how much money you want to part with. Good luck and remember once you start modding its hard to stop.

Cheer....Joe

 

no smog trouble here. mn6 get 4.10's. a4 get 3.42 w/3500 stall converter. You won't have any higher numbers to brag about but it will feel like you do SOTP. Do a search on the forum for gears and read what others have to say about them. Much cheaper than going inside the engine.