glass slipper

While at the SGC gathering, I got her on the dyno (finally, after 15 years). ~350 RWHP...the car is bone stock with ~50K miles on it and coolant temps were 205-210 *F. Runs were done back to back with no cool down.



I was expecting less as I'm having issues with the vacuum side of the secondaries (pump runs continuously with key on/engine off), but obviously they are going wide open at full throttle. I was really surprised at the A/F ratio as it didn't drop below 14:1 until after 4500 RPM and didn't hit 13:1 until right at the end. Definitely more power to be had with a tune to the richer side to allow more timing. I remember when the car had a problem with a bad spark plug under warranty (before they knew about the "pucks" falling off) and they did a data log that revealed timing was after TDC in a lot of places. The car always ran good so I chalked it up to the efficient combustion chambers not needing as much timing. I'll take care of some issues over the winter and get it back to Aaron's for a good tune...maybe he can coax 360 HP out of it.

As always, it was a great time at the SGC gathering and Aaron is a class act.

FASTAZU

Richard,

Was great meeting up with ya again....Nice numbers , drop me a pm I would like to know more about the timming issues you had and what was done about it, as it looks like that is what I am up against.

Steve

WydGlydJim

I'm pretty sure the Quasar Blue ones put down the best numbers!

GLmajer

I have a '94 ZR1 and had in on the dyno Sunday at West Coast Corvette open house. Numbers are very respectable; 388 RWHP and 382 TRQ. Only mods are Corsa exhaust, K&N filter and air box, and computer chip. This car beat a stock 2008 Corvette on the dyno! Lonf live the "King of the Hill"

Blown67427

Plenty of room for improvement.

kcl98

I think that puts you a stone's throw away from the most powerful numbers for a completely stock ZR1 - I think it's 352 - hope you get it.

KC '90 #2870

LowFlight

If I am not mistaken...the buyer of my previous 91 dynoed 360rwhp with a haibeck chip and B&B exhaust.

1990 QUASAR BLUE

Great numbers. I only made about five more with ported top end and flowmasters. Does anyone remember the difference between SAE and STD? I thought it was minimal.

glass slipper

Here you go:
http://www.woodcarbs.com/hpcalc.pdf
http://www.land-and-sea.com/dyno-tec...horsepower.htm

One link says 4% difference between STD and SAE. I ran the calculations using the correction formula from the other link to convert from STD to SAE conditions and came up with 4.5% (close to the first link's 4%). It should be noted that STD is also an "SAE" correction factor (J607) and the above two links are talking about engine dynos, not chassis dynos. What's referred to as SAE horsepower actually goes through a convoluted calculation where the engine is motored to determine friction HP or a 15% factor is used. Chassis dynos just use the correction factors related to weather conditions, not the whole SAE tests obviously. For a comparison, I made a chart below:

Weather.......Temperature....Humidity... .Barometric Pressure
STD/SAE J607..60°F.................0%........29. 92 in-Hg
SAE J1349.......77°F (25°C).......0%........29.234 in-Hg (99 KPa)
ECE................77°F (25°C).......0%........29.234 in-Hg (99 KPa)
Same as the SAE J1349, but does not use mechanical efficiency in the calculations.
DIN................68°F (20° C).....0%.........29.92 in-Hg (101.3 KPa)
JIS................77°F (25° C)......0%.........29.234 in-Hg (99 KPa)
Uses different correction curves than the others as a substitution for using mechanical efficiency factors.
SAE J1995......77°F (25° C)......0%.........29.53 in-Hg (100 KPa)
Gross HP rating used before 1972.

The new SAE J2723 rating (referred to as certified HP) that the C6Z06 and many new cars are rated under uses the same test procedure as J1349 above but requires independent witnesses and all engines submitted for testing have to be within +/-1% of its' rated HP and all production engines have to be within +/-2% of its' rated HP.

Correcting to lower temperatures and higher barometric pressures will yield higher "corrected" HP making it easy to see why STD gives the highest and SAE the lowest. Also explains why the same car here (SAE J1349) is rated higher in Europe (DIN). The C6Z06 is 505 HP here and 512 HP in Europe because of the different correction factors...many incorrectly thought the European version got more HP.

To say mine is one of the highest ones would have to undergo the scrutiny of what method/correction factor was used on the others to make sure we aren't comparing apples and oranges. But even then, different dynos even different days introduces enough error to really make comparisons an exercise in futility when only talking 10-20 HP difference. I estimate mine at ~334 HP SAE (using the calculated correction factor of 4.5%) making it middle of the pack if the others are at SAE (which I suspect is true). I was expecting around 300 HP because of issues with the secondaries which is why I felt like she did good...not because it is more "powerful" than the average. In retrospect, I should have calculated the SAE number and included it in my original post as I knew STD yields the highest number (ie nothing to get real excited about). But since the dyno sheet said STD, I assumed it would be redundant...sorry for any confusion.

1990 QUASAR BLUE

Great post, and informative as usual. There wasn't any confusion, I just couldn't remember what the difference was. Although, I thought it was minimal. For what it's worth mine only made 320/320 SAE when stock. So those are still great numbers in my opinion. I would certainly consider them higher than middle of the pack. Especially, considering the secondary issue and the fact that it's rather lean. I always thought the leaner it ran, the more power it made. However I recently had a local tuner tell me that's only partially true. I guess after a certain point, power starts to drop off again. So, I have to agree with everyone else. There's certainly more power to be made, just with a tune. Congrats again on the nice numbers, and thanks for the response.

4cefed

Nomatter what correction factor was used your ZR-1 is still a very strong running car. It was great talking with you during the gathering. Good luck with the car. It really looked fantastic. Love that color.

GTB/ZR-1

And Richard (and Carrie) have fun w/ it too...

Richard, how'd you do @ the NCCC event the next day?

glass slipper

Thanks Joel, I'm already looking forward to seeing everybody next year and hope to have more stories to tell/hear.

George
We had fun as usual but the really fast guys showed up this time so no overall FTDs this time. I did have several group FTDs though. The real story is Carrie. When she first started in my ZR1 a few years ago, she was about 8 seconds off my times. She slowly got it down to about 5 seconds until this summer when all of a sudden everything seems to have come together for her and she's gaining by leaps and bounds. If you remember at the last event in Oct (with the video), she was 3+ seconds from me. Last Sunday, she was only 1.8 seconds slower. That's getting close and the trend is not in my favor. I'm going to have to quit horsing around out there or she's going to start beating me before the year ends since we have three more days of racing. I never expected her to even get close to me...now I'm beginning to taste those words I'm going to have to eat when I told her she'll never beat me. When she does beat me, I'll be one proud dad.