AFVETTE

A buddy made arrangements for some of us to get on a dyno since we had just had headers installed and wanted to see what affect they had on our cars. He found a local DynoJet facility near our homes. $75 for 3 wide-band pulls. I know my car felt stronger but need to see if any of the other mods I had done since my last dyno pull had any impact on my "very rich" conditions. First, I dyno'd back in Feb 2001 when my 99 MN6 had 11,000 miles on it and 3 inexpensive and common mods, a LS6 lid, K&N air filter and Corsa Indy cat-back exhaust. My best HP/TQ from 3 pulls were 293 RWHP and 308 RWTQ respectively. Since this was a wide-band test we could see my Air to Fuel Ratio's. In a word my AFR's were horrible - dropping to 11.0:1 at 5200 RPM and falling to 10.1:1 by 5900 RPM's. They have a term for that - I was FAT.

I have since added a Blackwing air filter (they claim 15HP) removed the MAF screen (let's force some more air down her throat) NGK TR55IX plugs and MSD wires (without a hot clean spark the fuel won't burn). Then two weeks ago I had FLP headers installed with their high flow cats and x-pipe mated to my Corsa Indy's. $2700 in mods that should have added an easy 30 HP to my 99. I figured short of opening up the engine (heads and cam) I have done everything to address the LS1's breathing (well a new MAF was considered and rejected).

The results of yesterday's dyno were mixed and disapointing. I'm still FAT but my AFR's did improve to 11.8:1, my HP was up by 20 to 313 on my best pull but my torque was only up slightly to 313. There was an anomaly - you can see all the noise that starts @ 48 MPH (or 2200 RPM's if I had attached that printout) and stops at about 63 MPH or 2800 RPM's. The shops owner/operator seems to think it has something to with my MAF. He said he could feel it. I can't. But there could be a more simple explanation (one I wish I had explored before the car came off the dyno). That morning I installed a little gizmo I purchased from SLP last week. It's called an Air Temperature Module. It plugs in on the air bridge and it sends a false temperature reading to the PCM which allows the PCM to roll in 1 to 2 degrees more advance. SLP claimed 5 to 7 HP. I paid $29 for it and I bet that gizmo was the cause of that jagged reading from 2200 to 2800 RPM's. More snake oil I presume. It comes off first thing this morning. I wish I had thought to remove it and get another pull just to see if that was my problem. Now for the wierd part. My AFR's actually improved after 5200 RPM's and my HP kept increasing past 5200 RPM's. That's not common, most peak HP occurs at 5200 and then starts to fall off.

I have no ability to host pictures so if anyone would like a look at my dyno graphs/print-outs I'll send them via e-mail.

So the bottom line I gained 20 RWHP and 10 RWTQ from my lightly modded car. I'm still rich. The tech said a dyno tune could get me another 20 or so RWHP putting me closer to the 330 RWHP.

As a side note we had a 2001 Z06 test with us. he was 100% stock except for Borla Stingers and he recorded 319 RWHP. He was FAT as well. I'm seeing a trend with the LS1/LS6.

So I am back to the age old problem - HP costs $$$$$ and how much more do I need/want to spend to mine it? And to compound matters unless I do spend the $$$ then all the other mods installed (costing about $2500) aren't working in harmony with each other limiting their effectiveness. To reclaim my lost 20 or so HP will require an LS1Edit dyno tune.

I'm very disapointed since I see folks with BIG HP numbers and I'm struggling at 313. I've seen 100% stock cars beat 313. I need of a hug.

Tom

Conquer

Go with a cam and LS1 edit :smash:

:grouphug:

90 droptop

Tune it....

thegypsie

DynoTune it and you will be right where you should be while seeing HP/TQ increase for a relatively low price compared to other mods. My first 2 mods (the cheapest) were B-wing and Corsa's whith the bulk of gain supposedly to come from the B-wing yielded 320rhwp on my 99 with nothing else. That was very good IMO and used as the base for adding headers, cam, tuning picked up 50 rwhp and similar TQ. The next step was stage I heads and LS6 intake and another 23 rwhp.

Once the easy mods are done, assuming you are having a profesional install them, the $100 per 1 RWHP looks to be fairly accurate.

Tuning is the exception, best bang for the buck with your current mods.

Good luck.

Lance

gmblack3

I have never seen a Z06 dyno that low. How hot was it in the shop? A few local guys dyno'd before installing LG LT headers for a baseline. It was about 100*f in the shop. The 01 with stingers and vararam was in the 340s, this was down about 10rwhp from a dyno earlier in the year when it was cool out.

AFVETTE

We had a cool humid day here in St Louis, I think it was about 78 degrees in the shop, he did have the A/C running but both big overhead doors open. So no it wan't HOT.

As a side note (and I hope other buddies I'm refering to chime in) I have seen over 20 C5's dyno'd here in the St Louis area since 2001 and I have NEVER seen these BIG numbers everyone else on the CF report. I personally know 5 99/00 with all the usual mods and NONE os them are breaking the 315 RWHP mark. I'm beginning to wonder about some of these claims??? Or dyno's. (I saw that because why would two different facilities one in St Louis and the other in Illinois all "under report" power? Just doesn't make sense.

Tom

Mean Green

uhhhhh yup, seems obvious....hell, shoulda done that back when you saw you were rich in the 1st place :cheers:

And if you don't want to do that, get AutoTap and a MAFT as long as you have a laptop

thegypsie

Good point and beleivable, but now you have a base to work with and see gains per $$$. Your HP increase from original dyno #'s are a good indicator of what you got and track times as well will show the improvement. JMHO
:seeya

topless99

my 99 6spd. pulled 320 hp. & 331 tq. with a twin flow intake and corsa indys on carteks dyno.It also showed to be running a little rich. On a tight budget they suggested a cam and tune.

C5 StockSwap

That sounds like a very stingy dyno you have there at that shop. I usually see around 300 (or just under) bone stock numbers for C5's. Add an air intake and exhaust, and LS1-Edit, and I usually see around 320rwhp.

Subsequent to that setup, I added a cam and headers, and I hit 382 rwhp on 21st Century MC's dyno, which tends to be a little tougher than other local dynos, but just by 4 or 5 hp.

Good luck, and get that tune!

X_03_Cobra_guy

:lurk:
319RWHP (385 flywheel) for a 01 Z06 sounds right to me.
300RWHP (350 flywheel) for a 99 C5 sounds right to me as well
340RWHP (405 flywheel) for a 02-03 Z06 sounds right on too.

I don't think his numbers are off at all. With his mods he is real close to what the 01 Z06
makes. I think this particular dyno is more honest than other dynos. Or it is calibrated
better. Just take the car to the track and run it, see what you MPH is like. If your MPH
is going up your HP is going up. If your running 122MPH in the 1/4 your making very close
to 400 RWHP.

When you see a car that dyno's high 400-425 or so, and runs a MPH of 115 you know somethings
wrong. MPH in the /14 is not very senstive to traction and should be fairly consistent. So when
you see some wild claims with low MPH :yawn: ... then take your bad boy out there and run 120 :-)

Valdostavetteguy

I also have a 99' coupe w/MN6. I don't know what it had when stock, but it dynoed at 319 RWHP and 325 TQ (SAE corrected) with just Blackwing and Stingers w/x-pipe (no headers). It was done on a new Dynojet 248 at Norris Motorsports in Orlando Fl.

I would have to agree w/the guys that told you to get LS1 edit tuning done by an EXPERIENCED professional on a dyno ASAP. You should be at least 330 or even 340 afterwards w/your mods...

C5Longhorn

Something sounds off on that dyno to me. While your numbers seem low, I think something on the calibration of the dyno may be off.

With a tune, you should be in the 330-340 rwhp range.

WRK CAR

Time to tune it. :cheers:

MTWallet

Tom,
Sorry to hear your dissappointment. You definitely need to have it tuned and you will be amazed at what it will do. Its not just the A/F ratio that will build power. When everything is working together the power will be there. A good tuner will also use a Tech2 to check for knock along with other parameters. Trust me, if you get back on the same dyno and get it dynotuned you will be happy with the $$ spent. Shoot me an email and I'll talk to you about it.

Check the hp/tq #'s in my sig with just boltons (without headers) and you will see that they are very similar to yours. This is also without tuning. This will show you that you are really not that bad.

By the way, where did you dyno?


[Modified by MTWallet, 11:42 AM 8/31/2003]

vetterdstr

I understand how you feel, for years I added expensive mods to my car and really didnt get much HP... I did have a plan and was building up the esential areas for major HP. Either be happy with what you have or go out and spend a lot more money to get the big hp numbers.

VR :cheers:

cliffkh

Dynos will vary. Testing on the same dyno after mods will show your relative increases. Get rid of the timing tricker. Get an LS1 Edit dyno tune! You know you have a problem. This will maximize the investment you have made so far.

Then you can decide to put in LS6 manifold and cam which would be your next logical step if you still 'need' more.

jschindler

I've been to many "dyno days" at MTI - have had my two C5's dyno'd ther a total of three times. I"ve also read many, many dyno reports on this forum the past 30 months. I have never seen an 01 Z06 dyno below around 335. Also, with your mods, 335 is exactly what I guessed you should be at with your mods.

I think the dyno is suspect based upon the Z06 numbers. But I also think you have a lot going on with your mods. the MAF and the SLP item (can't remember what it's called) are very possibly throwing off the PCM. I do think tuning is well worthwhile. For all the bashing we give GM, the fact is that their engineers do an enormous amount of work to get everything working together, and not have one mod fight the other.

Don't forget that stock tuning "looks" for certain perameters. When it sees something that it is not supposed to see, it frequently goes into a mode that tries to protect the engine - killing horsepower at the same time.

Good luck and let us know what you find out.


[Modified by jschindler, 11:48 AM 8/31/2003]

CJS

I agree that you probably have 10 more horsepower than that dyno showed. I always look at any reported dyno as +/- 10 rwhp from variance between different dynos.
I would suggest that you get a 220 to 224 cam at about a .56x lift on 114 lobe seperation, and that will really wake your car up. Then later on if you need more, you can do the heads.

NEPTUNEBILL

It seems we always end up spending on avg a 100 bucks per rwhp, some mods a little less some a little more