Roto-Fab Intake and VMS Tune, what a combo!!!

[1992B4C]

The intake alone leaned the car out over 1/2 point A/F ratio

That's funny, EPP showed 1/2 point + richer and mine too!


I am not doubting anyones claims, I am just waiting to see them show up on my car. Also dont understand that Kevins test car and mine went richer and yours leaner!! Just trying to learn all I can here.

[liljon925]

what is the cost for both?

[NVR2FST]

I have to say, I was expecting lower numbers from the CAI (was thinking the typical 8-10rwhp). The car picked-up the 20+rwhp right away with no learning involved. I think Kirk did one or two pulls to back it up even. All were right there withing a few hp.

Once VMS re-tuned the car, it obviously picks-up even more. I'm very happy with the way the car drives, performs and sounds with the tune/ CAI.

As far as the low stock numbers, Kirk said even though the dyno corrects for weather, when it's really bad out they see approx. a 10rwhp loss. This puts my 292rwhp closer to the original 306rwhp. What can I say, mines slow I guess

Thanks to VMS for the great tune and Roto-Fab for the OE quality intake! We're lucky to have these products available to us.

[KyleMac]

Originally Posted by NVR2FST

I have to say, I was expecting lower numbers from the CAI (was thinking the typical 8-10rwhp). The car picked-up the 20+rwhp right away with no learning involved. I think Kirk did one or two pulls to back it up even. All were right there withing a few hp.

Once VMS re-tuned the car, it obviously picks-up even more. I'm very happy with the way the car drives, performs and sounds with the tune/ CAI.

As far as the low stock numbers, Kirk said even though the dyno corrects for weather, when it's really bad out they see approx. a 10rwhp loss. This puts my 292rwhp closer to the original 306rwhp. What can I say, mines slow I guess

Thanks to VMS for the great tune and Roto-Fab for the OE quality intake! We're lucky to have these products available to us.

Have the guys at VMS (or anywhere else) run dyno numbers on a stock G8 GT for horsepower at the crank so we can see how close the car comes to GM's 361HP claim?

If one car gets a RWHP readout of 292, and another at 306 (before any modifications)... does that mean that one of the cars doesn't really have the claimed 361HP?

[NVR2FST]

There is more to it than that...like stated before, the day can mess with the numbers a bit. Let's say my 292 was really 302 on a good day, then a 20% drivetrain loss= roughly 362.x hp. Now add the additional 48hp the tune/ CAI added and you have 410hp. Pretty good IMO.

Originally Posted by KyleMac

Have the guys at VMS (or anywhere else) run dyno numbers on a stock G8 GT for horsepower at the crank so we can see how close the car comes to GM's 361HP claim?

If one car gets a RWHP readout of 292, and another at 306 (before any modifications)... does that mean that one of the cars doesn't really have the claimed 361HP?

[JJohnson28]

Looking forward to puchasing the roto fab CAI....Anyone have the Roto Fab CAI w/ Video(sound) Clips?

[KyleMac]

Originally Posted by NVR2FST

There is more to it than that...like stated before, the day can mess with the numbers a bit. Let's say my 292 was really 302 on a good day, then a 20% drivetrain loss= roughly 362.x hp. Now add the additional 48hp the tune/ CAI added and you have 410hp. Pretty good IMO.

ahhh...

So, (and this is a completely a general question) when GM does their horsepower calculations on a car, how many tests do they do and how many cars do they use? I wonder if 361 is the best they could muster after doing maybe 50 tests with 10 different cars (weird that the G8 GT has 361HP while the 550i has 360HP, and there has been a huge ad campaign based on this).

44HP and 42Ft lbs. of torque seem absolutely huge for just an air intake and a tune. While this is great news... if VMS is willing to provide the info, have you come anywhere close to numbers this high in any other vehicle with just a tune and CAI? From what i have read, CAI's are generally only good for 10-12 HP max. Which is more along the lines of what 1992B4C got out of his CAI (roto-fab). Then again vhato got 42HP and 40ft. lbs. of torque out of his New Era Intake and Tune. Inexact science I guess?

For you JJohnson:
http://www.youtube.com/watch?v=97q63wH56_Q
http://www.youtube.com/watch?v=d9P5g...eature=related
http://www.youtube.com/watch?v=2JHV7...eature=related

[G8 Ray]

The HP came from GM during prototyping. Even in the engine build and assembly, engines are hooked up and ran on a dyno.
Like Ford's D35 ivct engine does 268 hp in stock trim.

[h3llphyre]

Quick question. Are you correcting for the lack of a 1:1 gear out of the tranny? If you are not, then these numbers start to skew in your favor, assuming you're dyno'ing in 4th, which is 1.15, you're looking at 15% better numbers to the wheels when compared to every other car with a 1:1 ratio. This means, our cars are reading about 30hp low to the wheels, when stock.

What this also means, is that those numbers you have for gains with the CAI and tune, are 15% higher, yeilding closer to 50hp gains to the wheels.

Or, you're actually taking the gearing discrepancy into account, our drivelines suck at life, and you're still pulling awesome numbers our of the tune/CAI.

Let me know. Maybe I'm missing something, but that's how I always understood it.

[h3llphyre]

Originally Posted by G8 Ray

The HP came from GM during prototyping. Even in the engine build and assembly, engines are hooked up and ran on a dyno.
Like Ford's D35 ivct engine does 268 hp in stock trim.

SAE requires an extensive testing procedure to ensure that manufacturers are reporting the power output correctly. In order for GM to make a statement on power out of the motor, they would have HAD to run through the SAE procedure, which means a production engine with production accessories and production exhaust manifolds/cats. Just a heads up.

[hugoG8#832]

Question.. can i do the security relearn with any OBDII scan device?

[Kirk@VectorMotorsports]

Originally Posted by h3llphyre

Quick question. Are you correcting for the lack of a 1:1 gear out of the tranny? If you are not, then these numbers start to skew in your favor, assuming you're dyno'ing in 4th, which is 1.15, you're looking at 15% better numbers to the wheels when compared to every other car with a 1:1 ratio. This means, our cars are reading about 30hp low to the wheels, when stock.

What this also means, is that those numbers you have for gains with the CAI and tune, are 15% higher, yeilding closer to 50hp gains to the wheels.

Or, you're actually taking the gearing discrepancy into account, our drivelines suck at life, and you're still pulling awesome numbers our of the tune/CAI.

Let me know. Maybe I'm missing something, but that's how I always understood it.

You are correct, you will see different HP & TQ numbers from the same vehicle depending on what gear you test in.

We perform all tests on the G8 in 4th gear. An eddy current dyno (the type we use) reads true torque at the wheels. The actual torque at the wheels is 490 lb/ft on the final run. This is the differential multiplying torque. The dyno then takes the engine speed and wheel speed and corrects the wheel torque. This is the number you see.

That being said, the gains are actual gains. This type of dyno would show the same gains regardless of what gear you tested in.

[Kirk@VectorMotorsports]

Originally Posted by hugoG8#832

Question.. can i do the security relearn with any OBDII scan device?

The security relearn is done by performing a "key on" "key off" cycle, no tool necessary. The CASE learn (crankshaft variation learn) is performed using a Tech 2 or Dashhawk scan tool

[hugoG8#832]

oh ok thanks Kirk. would a local shop be able to do the case learn for me? what i mean is it a common tool that every shop has or i need to go to the dealer. I planning on ordering on monday but I just want to make sure Im gonna be able to make it work in my car and I would love to buy the dashhawk but at the moment I dont have enough money.

[h3llphyre]

Originally Posted by Kirk@VectorMotorsports

You are correct, you will see different HP & TQ numbers from the same vehicle depending on what gear you test in.

We perform all tests on the G8 in 4th gear. An eddy current dyno (the type we use) reads true torque at the wheels. The actual torque at the wheels is 490 lb/ft on the final run. This is the differential multiplying torque. The dyno then takes the engine speed and wheel speed and corrects the wheel torque. This is the number you see.

That being said, the gains are actual gains. This type of dyno would show the same gains regardless of what gear you tested in.

Makes perfect sense now. I figured the axle ratio was entered into the dyno, but if it takes engine rpm versus tire speed, this makes it all a moot point.

Thanks for the info, even though you didn't have to explain it. So, going by the 15-17% loss through the drivetrain, your 44hp gains are pretty impressive at the crank.

I'll be ordering soon, once I get my stimulus check from the government. The wifey won't let me spend any more "normal" money for a while.

[FL_G8]

good question Hugo..

[Kirk@VectorMotorsports]

Originally Posted by hugoG8#832

oh ok thanks Kirk. would a local shop be able to do the case learn for me? what i mean is it a common tool that every shop has or i need to go to the dealer. I planning on ordering on monday but I just want to make sure Im gonna be able to make it work in my car and I would love to buy the dashhawk but at the moment I dont have enough money.

Some local shops may have the tool. They need a Tech 2 or other high end scanner. Any GM dealer will have the tool.

[GeorgeInNePa]

Hey Kirk, have you guys found the problem with the top speed limiter?

I "need" to go a bit faster than 138.

[hugoG8#832]

ya i agree 138 is just not fast enough....

[h3llphyre]

Originally Posted by hugoG8#832

ya i agree 138 is just not fast enough....

Actually, its not. I had an "emergency" last week. Car topped out at 138. Granted, it was probably a good idea to not go faster, but the car didn't feel unsafe at that speed.