TerryR

I know there's a lot of snake oil claims when reading about parts and the HP increases they provide. Wondering what are the most common or should I say proven mods to get to 400HP? Thanks Terry

CJS

I researched my mods in sig carefully, and they work well. You will also need a hotter cam and/or ported heads to get to 400rwhp though.

vetterdstr

Heads and Cam!! :yesnod:

vetterdstr :cheers:

ITSovr4U

I quess nobody read your question properly. I have a 99 HT and with vortex rammer air intake, flp headers , Zo6 intake, b&b exhaust , 160stat, x pipe, and granatelli maf. I dynod 342rwhp and 356rwtq which at the flywheel is more than 400hp. I ran 12.7 on runcraps. This was without any kind of tuning. I hope this helps, you did say flywheel horsepower correct. :crazy: :steering: John

Allthrottleandsomebottle

400+ Flywheel HP........ram air intake, catback, Headers & computer tune should be 400 at the flywheel.
You will spend around $2,700. Auto or stick?
I have to be close.... mine is an A4, dyno @ 310hp/320tq
:thumbs:
If you mean RWHP per a dyno....add nitrous or as stated above :D


[Modified by ALLTHROTTLE&NOBOTTLE, 7:52 AM 4/1/2003]

vetterdstr

I read the question, and I am not going to tell the guy to get an air box and headers with an underdrive pulley to get him to where he wants to go... Heads and Cam are the the only way to go IMO for HP on these cars.. All this bolt on stuff for $1,000 a pop is just crazy and can lead you to being let down most of the time. :crazy:

vetterdstr :cheers:

AC54ME

Heads and cam! Also, since it is easier to do with the H&C activity, put some headers on. :smash: :smash: :smash:

STAGED

Honestly no pun intended, if 400+ FLYWHEEL hp is all that you want, the most proven way is to BUY AN '02/'03 Z06. Combined with 7 yr./100k aftermarket warranty, you can't have better assurance for your output criteria.

C5B

I also say heads/cam & tuning. You can easily surpass 400bhp (flywheel) with that combo, and you don't have to be any louder to get there. With a mild cam, ported/polished/milled heads and tuning, you will still have a very driveable car and no one will even know you have the power under your right foot until you punch it..... will even pass smog with the right cam.

Of course, if you want SOUND fast, then you can spend the same amount on other mods that will smoke your ability to pass smog.

- C5B

Do you want to go fast or SOUND fast? :lolg: :lolg: Someone else has something similar to this....

Scott97

Don't waste time with B.S. mods.

Throw a cam, or a heads/cam package in there, you'll be happy you did :).

Just my opinion.

FRC sexi blk

My goal as well was to get at lease 400 fly wheel HP without any major engine modifications like heads and cam.

for about $2,000 to $2,500 you can add more than 50 HP to your c5.

First gave my oil consuming engine a flush and fix:
-GM top end engine cleaner (decarb) $10
-PVC mod $12

Performance mods:
-K&N fipk (cold air shroud design) $375
-remove maf screen/polish it $0
-Throttle Body coolant by-pass $0
-LS6 intake manifold $400
-175 degree adjustable custom stat $0
-SVO 30 lb injectors $220
-NGK tr55 copper plugs $20
-Corsa cat back (no HP gain, just best sound ever) $450
-LS1 edit (4 member GP) $150
-Ease OBDII scanning software (use friends) $0
-Tune from professional corvette tuner vial email $375

Ls1 edit real HP =396 fly wheel HP
Total money spend=$2,012
Current MPG =26 city/36 highway

Since the cat back doesn't give any performance gain, you could get some long tube headers for about $600 and have over 400 fly wheel HP, but I decided Corsa Indy’s would be less trouble. I did all the labor myself.

The best benefit to this is the ability to have my car re-tuned for almost nothing if I add more mods like headers or heads/cam, or nitrous. I'll have more power than those people who only installed Heads/cam without the rest of the bolt ons. I also have a "gas mileage" tune, and a performance tune. So all it takes it the click of a button and my car is saving the gas when I want :cool:


[Modified by cute301guy, 7:53 PM 4/1/2003]

4DCYKEY

It is up to you. I disagree with the H&C only statements.

Starting with the 350 hp you have, you can get the 400 flywheel hp you want with a number of air intake choices plus headers and exhaust. The exhaust will not give you much in terms of horsepower but will look and sound better than stock.

Or you can go with having heads and cam which will definately put you over 400hp and hope that it doesn't affect your smog certification. But, I'm willing to bet that if you go the H&C route, you're going to want to add headers, intake filter, and exhaust anyway...now, you've doubled your cost.

Good luck with your choice. :cheers:

camiv

I think it is very easy to get 400hp at the motor without doing heads and cam. If your going to keep this car the heads/cam will end your warranty unless the dealer does not know or care! That's a chance someone must take. With an air induction system, headers, and tuning you can get close if not there. In addition, I added a ported throttle body, x-pipe, cat back exhaust, and a soon to be in 3:73 rear end. The rear end will be the best driving upgrade I think I will have made today! The throttle body might be the shop peoples b.s. sales pitch along with the x-pipe. The cat back was a must for me because of the look and sound but actual hp on the second set of mods is not meaningful. If you just want 400hp.....due the first three on the list and go from there. Hope this helps! :D

vetterdstr

Those of you who think you are really getting 400+ hp out of a bolt on car have never really done it have you? Man, I spent alot of money on my car and barely had that... I should have done the H&C thing right off of the bat... I could have had more then 400+ from the H&C for the same price. Oh well... live and learn.

Here is to you making the best mod decisions for your situation.

vetterdstr :cheers:

corvette_karl

I don't think you'll quite get there with just bolt ons.

Most cars benefit by upgrading the exhaust, but the C5 really doesn't have much more horsepower to gain there because it already flows so well. I'd do it just to wake up the sound of the car though. The previous owner of my car put the Flowmasters on, but you can do a lot better than that . . .

IMHO, I think the most power is to be had in the heads, the cam second. After you do all of that, to get the most out of your investment, you'll want a cold air intake to feed those mods and headers to get the gasses out efficiently. Maybe even a Z06 intake manifold . . .

I think some of the supercharger solutions out there are pretty awesome and compete with the Heads/cams packages in cost, and the rest of your motor remains mostly stock.

Of course if you really want to get there cheap, you can just add spray, but then you only get the power some of the time.

Good luck!

C5B

Look better = personal choice.

Sound better = personal choice.

Heads = No change in smog - fact.

Cam = No change in smog for mild cam... such as 02+ LS6 cam - fact.

I have yet to see a dyno chart where someone started with 300rwhp (MN6) and ended up at 350+ rwhp (around 400fwhp) just from intake, headers and exhaust - and still pass smog. Shorty headers are usually a waste of money unless accompanied by nice heads. Long tubes usually cost $$$ and will send your smog cert tester into hysterics when he does the visual inspection.

Ported/Polished stage II Heads, 02+ LS6 cam and Blackwing will deliver around 400 fwhp and will pass smog with flying colors.

- C5B

Mopar Jimmy

All you need is a CAM, Headers, z06 intake, prof. dyno tuning via ls1 edit and you are good for about 425rwhp. From what i seen the if you only want 400 fly wheel horsepower there is no reason to spend the extra money on heads as the stock LS1 heads flow great and the CAM is what really WAKES UP the LS1. Many LS1 cars are running high 11s on stock heads with the mods set forth above.

GOOD LUCK,

MTI 427 ROadster

4DCYKEY

I didn't do a baseline so I don't know what I started with, but I have seen on this forum people who I bet started with more baseline hp than me. I'm at 331rwhp SAE with my bolt on mods which is about 390 hp using the common .85 factor. 340rwhp equates to 400hp with a manual transmission. The newer vette starts out with 5 more hp and has the better intake manifold which should benefit more from the headers and get you within a +/- 400hp. I'll let you know about passing smog in a couple of months, but I don't expect any problems... :)

Allthrottleandsomebottle

I take mine to the drag strip..........the top end MPH is a true indicator of HP.
ET is effected by traction...........but still a good indicator of torque.
We will see what the headers did soon enough. should be 111 mph.
With an A4, stock TC,and 3.15 gear, that has to be near 400 FWHP.
Besides, this is my WIFES EDD, that is enough power for her to get into trouble :lol: (She has)
Now my LS1..............cam,heads,headers,TC & gear for sure.....some things never change.....68' Camaro.........C5........stock.... :U :cheers:

C5B

Someone correct me if I am wrong, but I think the standard is actually .87 and .80 (13% loss in MN6 and 20% in A4). So, 400bhp should be around 348rwhp, and 331rwhp should be around 380bhp.... pretty close to 400!

- C5B