Test results before mods

djdawson2 · 11-08-2009, 11:16 PM

Not sure what the "feeling" is about the use of the G-Tech on this forum... but I wanted to test a little prior to changing my turbo and intercooler, just as a sort of baseline.

I've had very positive experiences with the G-Tech in the past, having used it while doing runs at a dragstrip, with the largest error being 6/100's of a second.

Anyway... my car is an '89 that is essentially stock with the exception of Brian's muffler. I live in Colorado, and I did my runs at slightly above 5000ft.

0-60's were repeatedly right at 6 seconds. 1/4 mile runs were also a very consistent 14.1 @ 107mph.

One thing I learned, is that it seems there's no good way to launch this car. I tried a half dozen different methods... most resulting in a major bog, and one that was too much for the clutch. Regardless of the type of launch, the results were always about the same. The telltale figure is the 60 foot time. I was never able to get below 2.5 seconds, which is very poor. I routinely have been able to get 1.6 second results out of my other cars.

I'll be installing the K27 7200 with a B&B intercooler soon. It will be interesting to see what sort of change those provide.

That's it....

beepbeep · 11-08-2009, 11:21 PM

As 0-60 times are too inconsistent and depending on clutch/traction, I suggest logging a full boost run in second gear. It's short enough not to let you run off the road, but long enough not to care about traction (assuming dry straight road).

I usually log RPM's in 2:nd or 3:rd gear using LM1 + AuxBox and superimpose those two in the computer in order to look for improvement.

djdawson2 · 11-08-2009, 11:29 PM

I guess I'm looking forward to the time when traction is an issue. Right now, it isn't. My times were very consistent for both the 0-60 and the 1/4 mile. Neither was impressive, but you have to start somewhere.

jpnovak · 11-09-2009, 04:28 AM

Yep, I log rpm vs time and convert to a "dyno" number.

StreetDyno - Dyno your car from home. My own physics model

I just built a 3-axis accelerometer datalogger ($70 in parts) to refine the method.

wjfk32 · 11-09-2009, 04:51 AM

0-60mph-Not worth it...INMOP..930's,965's Are meant from a rolling start or top-end for highway...You are going to cause alot of drama, damage and $$$ to your clutch and gearbox..I don't like to abuse my old school car that way.

60-130mph--Is the real test...I would just go side-by-side with a fast car or V-box and see what happens...Safety 1st.

Walt

djdawson2 · 11-09-2009, 07:15 AM

Yeah... trust me I don't envision my 930 as being a strip car, but just wanted to see what it would do. Needless to say, 1st gear in that car is too long for taking off hard... just too much abuse required.

To address the Safety Team... I have a nice flat access road in a rural area that no one ever seems to use. This is where I've tested my cars for years. Don't worry, I won't give the P-car guys a bad name by doing silly testing in public areas.

I think the mph tells a better story. 107mph is pretty high for such a slow 1/4 mile time.

Also, the G-Tech does do a nice job of logging hp and torque vs. rpm. It tends to deliver a substantially lower figure than a chassis dyno, but at least you can get a number to compare as you work on the car, as well as graphs to overlay. I think the G-Tech offers a huge bang for the buck.

Garrison · Garrison's Garage

Once you put the K27 on, you should notice a difference for sure. When I went from stock to K27S only the car was night and day difference. IMHO I think it makes the car a lot more driveable then the factory turbo...

tj930 · 11-12-2009, 09:43 AM

Best GTech 0-60 time I ever had was 4.5 seconds, with a standing1/4 of 12.8 seconds. But my car felt more powerful than it does now, had a Kelvar clutch (which could take some abuse) and - if I'm completely honest - the tarmac may not have been 'billiard table smooth' (i.e. bit of a dip in the middle).

Funny, some of the very best launches I've ever done, I wasn't even trying! I'd recommend NOT going for the '4000rpm-dump-the-clutch-come-what-may approach' - if the clutch doesn't bite, you're going to do monstrous damage to it; 2250rpm-ish with a very small, deliberate bit of clutch slip works better.

Anyhow - you've got an '89 5-speed model, so you should be getting 4.8 seconds!

djdawson2 · 11-12-2009, 09:52 AM

Quote:

Originally Posted by tj930

Anyhow - you've got an '89 5-speed model, so you should be getting 4.8 seconds!

Keep in mind that I was testing at 5000ft above sea level... a very real disadvantage.

I won't dump the clutch. I'm too much of a gearhead, and know the consequences of a shock load. Nonetheless, I've been successful at slipping the clutch for a good launch on other cars... just not the 930.

With the 7200's lower boost threshold, I'm betting it will get out of the hole a lot faster, and with less stress on the clutch.

I will soon know for sure.

WinRice · 11-12-2009, 10:57 AM

Quote:

Originally Posted by djdawson2

Keep in mind that I was testing at 5000ft above sea level... a very real disadvantage.

Which can be compensated for with the right turbo and a little more boost.

djdawson2 · 11-12-2009, 11:08 AM

Quote:

Originally Posted by WinRice

Which can be compensated for with the right turbo and a little more boost.

Not true. There is no substitute for air density. More boost = more heat, less power. BTDT with a lot of turbo cars.

But the turbo certainly does help to reduce the losses...

WinRice · 11-12-2009, 11:17 AM

Quote:

Originally Posted by djdawson2

Not true. There is no substitute for air density. More boost = more heat, less power. BTDT with a lot of turbo cars.

But the turbo certainly does help to reduce the losses...

Well......not a perfect substitute, but you got what I meant.

You can reduce the additional heat a little by using a compressor sized for the higher PR needed at higher altitude, rather than a compressor sized for sea level applications. Not a perfect solution, but better than what the NA guys have to work with.

Look up 'Brent930'. He's not as active on the forums as he used to be, but was a pioneer in pushing the limits of CIS. He was in Ft. Collins and had a CIS car with around 450 RWHP.

djdawson2 · 11-12-2009, 12:55 PM

Yep, I hear you. Until we get spooled up, however, we're at a serious disadvantage over the NA guys!

WinRice · 11-12-2009, 01:02 PM

A Yugo could beat my car off the stoplight..................LOL

Unless I really want to abuse the clutch.

djdawson2 · 11-12-2009, 01:25 PM

Yeah, I don't think I've ever tested a car that took me 2.5+ seconds to get through the 60 foot mark.

RarlyL8 · RarlyL8's Garage

A good test is 30-100mph. Passenger can run the stop watch.
To launch I let the clutch out fully as if driving away from a stop sign and then stomp the gas. 60 foot time is 2.5sec and 1/8 mile time is 8.5sec which tells the story.

tom84930 · 11-12-2009, 03:01 PM

I made a number of modifications to my CIS engine: K29, 964 cams, full bay intercoooer, headers, muffler, et cetera. Once it hit boost it was amazing. But until boost it was a dog. Then I installed an 8/41 r&p. The off the line difference is almost un believeable. The car takes off like a scalded cat. And I don't have to dump the clutch at 4000rpms to make it happen. The stock gearing on 930s makes attempts at fast starts costly and embarassing. Either changing the r&p or the transmission gearing can turn it into a different car. Just my two cents.

911st · 11-12-2009, 04:04 PM

I love the K27-7200 and chose it over the K29 & HF. However, I am wondering sense you are at such altitude, maybe one of the larger K27's might be beter where you live. Depends on your goals.

I belive that one of the mags when they did drag starts on a CIS turbo I belivew they started at 3000rpm letting out the clutch and getting on the throtle at the same time.

However, I used the acceleration in gear method as my base line. I would start at about 2000rpm steady state, run up to 6500rpm and time it. Also worked well in a higher gear to make note of where the boost started to come on and where it hit full boost.

forwheeler · 11-12-2009, 05:51 PM

tom84930
Does the R&P seem too low for highway or other driving?
I am interested in this since this seems to be a great way to lower spool time as it were for the track especially.
Where did you get the set? Can you give me an idea on cost?

tom84930 · 11-13-2009, 10:55 AM

Forwheeler:
If I recall correctly, the 8/41 r&p was in the neighborhood of $2000. The transformation is mindblowing. i'm way too old to be street racing, but I must admit to a couple of stupid, but illustrative lapses. A little over a year ago I blew away a Mercedes AMG63 off of a stoplight for a couple hundred yards before I regained my senses and braked. This past spring i did the same thing to a Z06 between two stoplights. The car's freeway behaviour is definitey altered by significantly higher cruising rpms. It's a tradeoff I don't mind. If you can find s fellow-930 owner with an 8/41 or 8/37 it would be good to take a drive before you commit. If you happen to be in Minnesots between April and November I'd happily lend you mine.