EVLGTO

I'm taking bets!! Just kidding

My buddy and I are just making a friendly $10 bet on what hp I'll make with my mods. Hopefully having it tuned this Friday, just finished up the cam install. Here is my mod list for my 2000 C5 FRC:

Ziptie mod with k&n filter
LS6 intake manifold
LT headers
Deleted pup cats(still running main cats)
Magnaflow XL system cat-back exhaust
Jegs cam 228/230 .585/.585 112lsa
Scoggin Dickey Dual valve springs/titanium retainers

Car has 28k miles on it. He says I'll touch 400whp, I think I'll be at 389whp. The car will be dyno tuned on a dyno where the axles bolt to the dyno machine, no rollers. Take your guess everyone!!

Robrote

354 rwp

'Shifter

362rwhp.

chris308

370

grantv

Dang, I wanted 370... I'll pick 364

JR-01

365

Grandpa1

364 1/2

road pilot

395

lewislgZ06

Time for a C-5

375

Evil-Twin

Since all dynamometers are based on the software used and the actual mechanical integrity of the dyno. Of the three, Dyno Jet, Mustang, and the third and least accurate Portable Dyno-mite ( portable axle mounted dyno ) The DynoJet is the most favorable for printing out higher HP and torque numbers, and the most accurate of the three; Mustang dyno. None of these are capable a showing true HP at the crank, without a variable drive line calculation, which would have to be changed for each car since all cars have different drive line drag. GM uses a true dyno to measure HP and torque at the crank. Keep in mind that dynos are all accurate in delivering relative numbers. meaning, if you use the same dyno, and add a modification, it can measure the difference between the before and after. The difference in these three dynos could be as much as 50 HP and torque at the wheels when measuring the same car. So with all that in mind, the topic line says it all.. " Its a Guess ", even when the dyno prints it out. Understanding what a local shop, or a portable dyno delivers will help understand that none of these are actual true HP or torque numbers.. just a relative base line to use the measure changes. OH and BTW, the more sophisticated todays cars become to overcome driving conditions, the less accurate these shop dynos become. If you want some sort of bragging rights, use a DynoJet. If you want closer to actual numbers, use a Mustang dyno. They can all measure changes in engine modifications.
Bill

Vetteman Jack

Good info by E-T. I'll take a guess and say 375 rwhp.

EVLGTO

Great information and thank you. The dyno that I use to have my cars tuned on was a Mustang dyno. But unfortunately my friend is just too busy to tune my car. So this will be the first time I've ever seen one of these types of dynos used. Didn't know they show lower numbers. Either way, numbers are numbers. ET and seat of the pants will say it all. But like you said before, as far as measuring when I do more mods, it will be my new dyno/tuner I will he going to.

Evil-Twin

Just a few more thoughts. when a car is sitting on a dyno, with the hood up, and a large fan blowing on the motor, it has no actual relationship to that car on the street or track. Things like lift and drag, ambient air temp, and barometric pressure, wheel alignment, tires, all rotating drag variables ( wheels and tires, torque tube, bearings, transmission, clutch , differential drag, etc ) all are demerits to static dyno numbers found in a shop pull . A slippery, ( aerodynamic, lean car at the wheels can have as little as -10% Hp and torque from the crank, and a poorly prepared or a fat car can detract as much as -20% from the actual engine HP at the crank.
I hope this help people to understand true HP and relative HP.
Bill

Chris Draper

What cylinder heads are on the engine? I have similar mods (cam, LS6 heads, LS6 intake, LT headers, x-pipe, exhaust, Varraram ram air intake & air bridge) and I just tuned at 422rwhp on a Mustang dyno.

The cam is the biggest variable. I have a 224/224 563/563 114LSA.. You should see around 390-400.

EVLGTO

Chris, I watch your channel and follow you around on Instagram. No offense, but I highly doubt you have a 224/224 on a 114 lsa. Your cam is very beastly with more than likely aggressive ramp rates. Did you finally find out what cam you have in your C5? Your cam sounds like my old 239/242 .620 113lsa cam I use to have in my 06 GTO. It was a beast and yours sounds very similar. My friend has a 224/224 .585/.585 114lsa comp cam with XER lobes and his sounds nothing close to yours on his ls2.

As far as heads, I have the stock 853 heads on my car. But I did pick up some 243 heads with only 20k miles on them from an 04 Z06. I'm porting them and then going to have a valve job done in the winter.

Rob 02

With the 243 heads and a tune you basically would have a LS6 engine with CIA and a hotter cam. I would expect similar results as others with similar mods.
You might see a 50hp gain over the LS6. The heads may account for about 15-20hp. You could gain 10-15hp by raising the compression ratio a little. If you do I would lower the temps to keep the heads cooler.

Without a tune you may not see much of a gain.

EVLGTO

I always have a tune done. Having a dyno tune makes such a difference on a car, especially LS powered cars. Even if I wasnt doing a cam and heads, I'd still get a tune.

Mistrezz 06

399

Time for a C-5

As far as heads, I have the stock 853 heads on my car. But I did pick up some 243 heads with only 20k miles on them from an 04 Z06. I'm porting them and then going to have a valve job done in the winter.[/QUOTE]

Are we guessing on the 853s or 243s?
My 375 hp guess was stock heads
I have a similar mildish cam (222/226 .600) with ported 243s and it hit 402hp on a dynojet.
I'll guess 400 with the heads.