Topic: Dyno numbers between Cobalt and Kappa (LNF)

[Kelu]

Many of us see on the Cobalt side many high numbers on the dyno even the engine is the same.

A kappa barely touches 300whp on a Dynojet with race gas and lots of fine tuning as SnapOnBob shared us.
In meantime the Cobalt guys are showing easily 310-320whp, some even reaching 350whp with meth or race gas.

A guy just shared his experience over the time which I consider very good as example:

The car was dynoed on a Dynojet with all runs using SAE and a smoothing of 5. All runs made in 3rd gear.

Stock 243whp and 234wtq - 13.5 at 104mph
HP Tune and K+N drop in - 291whp and 311wtq - 13.4 at 110mph
ZZP downpipe, charge piping, and intercooler plus welding tip mod - 310whp 366wtq
ZZP air intake tube - 318whp and 364wtq

http://www.cobaltss.net/forums/dyno-results-170/my-results-bolt-tuned-08-a-237674/

This pretty much confirms those are "high numbers". Why?
IF stock 243whp is real power to the ground that means this engine makes 260bhp no matter the gas, atmospheric conditions,etc and it has only 6.5% drivetrain loss??? For me that is too hard to believe.

Second mention, he went from 243whp (13.5s) to 291whp (13.4s) and dropped only 0.1s at the dragstrip even the difference of power was 48whp?

I did this topic only as matter of information, I have nothing with Cobalt guys, I like watching them pushing LNF and learn from their experience but the hardest part is to know the power because we live in a relative world.

[Arabas]

First of all, Cobalts are FWD, so i suppose it is reasonable to make more whp coz we have many drivetrain losses.
i thought that in our cars, all dyno is made with 4th gear (being close to 1:1). why this dyno was made in 3rd gear?
about the 13.5 vs 13.4, could it be a typo?

[Kelu]

Even Cobalts are FWD I don't expect to see 6.5% drivetrain loss in the same time with LNF functioning at 260 bhp no matter the conditions.

Cobalt gearing have different ratios than Kappa, their 4th gear is not 1:1 as kappa, their closest to 1:1 is 3rd gear that's why they generally dyno in 3rd.

Don't think there is any typo in 13.5 or 13.4.
I dropped from 13.5 to 13.3 with a difference of 17whp. When I had only tune I did 13.5, after exhaust I gained 17whp and my new record was 13.30s (here is the topic about dyno before and after exhaust )

[2.0 tspeed]

Most of all my cobalt buds dyno between 290-320w and most trap 112 in the 1/4 they are a better platform then are kappas in straight line racing from a roll race I'm dead even with all of them till about 100 then they start to pull

[Kagem]

It doesn't matter if the dyno is happy, what matters is the gains, which are 75whp. The drivetrain loss in a front wheel drive is around 15%, so that would be for the cobalt around 225whp in stock mod. Calculate the 225+75, that makes us 300whp, voila!

[Kelu]

Cobalt better platform than Kappa? Are you sure about that? Don't know what are you referring to platform but I'm thinking a car is build from parts now you tell me how good is the cobalt clutch and gearbox compared with a Kappa. I don't know other parts which are better in Cobalt than in Kappa.
You loose races from roll because of gearing not because of the platform itself.
Another thing, FWD always finish with higher mph at the end of quarter mile than a RWD. BUT tell me how a Cobalt face a Kappa from 0-40
Tell me their ET times with street tires and no prep tracks and we can compare with mine or the other kappas who visited the strip.

Kagem your idea is good but 75whp difference in a stocker dynoed at 240whp is way different than 70whp gained over stock which have been dynoed 220whp. Gains should be in percentage.

[2.0 tspeed]

Cobalt> kappa in a straight line kappa> cobalt everything else

[Kelu]

slowsol: when you did this http://www.kappaperformance.com/forum/index.php/topic,5982.msg83469.html#msg83469 there were Cobalts with similar mods with yours dynoed?

[2.0 tspeed]

No not that day it was just me and a bunch of srt4's lolz

[Kelu]

It will be very interesting to see similar modded Cobalts and Kappas dynoed on the same dyno.

[2.0 tspeed]

I'll try next dyno day

[snaponbob]

Again, the tired old advice of dynos is invoked again - the actual numbers are not as important as the IMPROVEMENTS. The ONLY valid comparison is to strap down a stock LNF Cobalt, run it, then strap down an LNF Kappa and run it. THEN compare the stock numbers. That said, some thoughts;

1) The mig welder tip mod (known as "the pill") will NOT hold higher boost levels, but rather it allows the turbo to spool up quicker and spike high boost. Once the pressures equalize across the orifice, boost levels are whatever the car and tune can produce. I know - I have that mod.
2) Cobalts have electric power steering, not belt driven like the LNF. That is part of the apparent whp differences.
3) The most highly massaged drive train will not produce a 6.5% loss. There are just too many places to have losses. This is such an important number in racing that race shops will spend endless hours going after 1-2 point improvements. NASCAR teams have dynos set up to massage gearboxes, diffs, even u-joints and axle bearings. Been there, seen that. They get pretty excited when they get in the single digits.
4) There is a LOT of "dyno racing" in the Cobalt/HHR communities. A little reading and a few PMs will expose a bunch of ...... umm ............ optimism.
5) Every time I have seen manual box cars dyno tested, it was usually in fourth gear as that is normally a 1:1 ratio in 4 and 5 speed boxes. Why Cobalts would be run in third is odd. It may be a clutch issue as Cobalts and HHRs are known for smoking clutches once they start getting near 300whp.
6) For a given power output, a Cobalt will almost always out drag an LNF to 60 as Kappas have to shift at 57 (assuming a 6200 rpm fuel cut off) and Cobalts go over 60 in second.

[DeepBlueGXP]

I heard that colbalts clutches go out a lot sooner and can't handle over 300 hp. 

I made spreadsheet to display loss. (selectable)  The Kappa is about a 15.5% loss based on all the dynos I've seen
Base stock LNF Kappas HP range from 218-220 = 15% loss

If a Base stock LNF Cobalt HP range is 240-245 = 6% loss

Remember this too, the Cobalt has a electric steering assist, not a pump like us, our pump is parasitic which adds to the HP loss

The attached table shows the base LNF, GMPP and a modded LNF with a selectable loss range for the modded LNF.  My car is putting out 286 WHP which makes my base about 337

[NormSky]

Love to see FWD try to put the increasing amount of power. It can be done but not streetable. Aerodynamics play a big role at higher speeds.

[U4EA]

1) The mig welder tip mod (known as "the pill") will NOT hold higher boost levels, but rather it allows the turbo to spool up quicker and spike high boost. Once the pressures equalize across the orifice, boost levels are whatever the car and tune can produce. I know - I have that mod.

So what is the tip size and its location? Is the size dependent on tuning factors or standard? Thanks for bringing this back up, remember this discussion going on with Lil Goat/Mr Prickley/The Comedian/Old Goat before he disappeared last Feb.

[NormSky]

U4EA, the blocking of the line to the waste gate just causes it to stay closed longer. Same as a copat controller does on a non-electrical wastegate.

[snaponbob]

There is a pressure sensor on the front of the turbo. The "pill" goes in there. I tried a .030 mig tip which had a .038" opening. The results were too sudden for street driving (really irritating to tip in a gas a little and have such a big momentary surge) and presented issues when racing (especially at 2800-3400 rpm) so I opened the orifice to .050.

[U4EA]

There is a pressure sensor on the front of the turbo. The "pill" goes in there. I tried a .030 mig tip which had a .038" opening. The results were too sudden for street driving (really irritating to tip in a gas a little and have such a big momentary surge) and presented issues when racing (especially at 2800-3400 rpm) so I opened the orifice to .050.

Thanks! 

[U4EA]

U4EA, the blocking of the line to the waste gate just causes it to stay closed longer. Same as a copat controller does on a non-electrical wastegate.

Sounds like either could be detrimental to the turbo if not done correctly.?

[snaponbob]

Probably, but so far ........................ no issues.

[Brazen17]

Second mention, he went from 243whp (13.5s) to 291whp (13.4s) and dropped only 0.1s at the dragstrip even the difference of power was 48whp?

Could be having serious traction issues with the increase in HP. His trap speed went up nicely but maybe no grip at launch?

[POS VETT]

Here is my side.

The drivetrain loss from a dyno test is static; it varies relative to the speed.  The C5/C6 Corvette manual transmission (T56 or T6060) and rear end lose about 50 hp.  About the same number in the '4-'7 Cadillac CTS-V.  

The Kappa, with its equally-longitudinal configuration, has the same number of gears and gear configuration.  My '5 CTS-V and my '8 Kappa supposedly have the same rear end.  The only difference is the transmission.  I assume that the Kappa transmission is a lighter duty as it doesn't live behind a 400hp engine toting nearly 3,800 lbs.  That means the loss is just slightly less compared to a C5/C6/CTS-V drivetrain.  My guess is about 40-45 hp.  

With the Cobalt being FWD, the power loss is even smaller, maybe in the 35-40hp range.  There is no long drive shaft to spin and there is no transferring power through the right angle.  So, when comparing Kappa to Cobalt, there should be a difference due to drivetrain efficiency.

[LatinVenom]

An experience drag racer on our Kappa with drag radials and tune, plus exhaust changes can get to the 12.8, 12.9 numbers.
It has been publish here.
Love the Dyno racers and their numbers...............

[snaponbob]

Here is my side.

The drivetrain loss from a dyno test is static; it varies relative to the speed.  The C5/C6 Corvette manual transmission (T56 or T6060) and rear end lose about 50 hp.  About the same number in the '4-'7 Cadillac CTS-V. 

The Kappa, with its equally-longitudinal configuration, has the same number of gears and gear configuration.  My '5 CTS-V and my '8 Kappa supposedly have the same rear end.  The only difference is the transmission.  I assume that the Kappa transmission is a lighter duty as it doesn't live behind a 400hp engine toting nearly 3,800 lbs.  That means the loss is just slightly less compared to a C5/C6/CTS-V drivetrain.  My guess is about 40-45 hp. 

With the Cobalt being FWD, the power loss is even smaller, maybe in the 35-40hp range.  There is no long drive shaft to spin and there is no transferring power through the right angle.  So, when comparing Kappa to Cobalt, there should be a difference due to drivetrain efficiency.

How can drive line loss be static on a dyno? Put thinner oils in the box and diff and the losses will go down. Spinning a driveshaft will not change the delivered power at the wheels once the shaft speed has become relatively constant. Driveline loss can be seen if the dyno trace is viewed AFTER the throttle is closed and the drum is spinning down to zero speed, and the next time I dyno my car I will discuss this with the shop owner. Certainly, guessing losses is as valuable as guessing outputs!!!

[POS VETT]

Sure, if you change the drivetrain oil.  Transmitting 400hp peak or 450hp peak through the same drivetrain will not change the number of the loss.  It's still ~50hp in the case of Corvettes/CTS-V.