mongrelcat

I would assume you're running a 98RON program? Have you checked with Steve Wong? From everything I've read (mostly on Pelican,) his support for the product is very solid. Good luck in sorting this out.

delanobe

I had the same when I installed the cat bypass and the K&N filter.

I did a Dyno run and lost some hp but nothing dramatic.
Now with a new chip + cat bypass + K&N the car is stronger than before in the whole rpm range?

Maybe the oem software is not ok for these modifications?

Thoughts?

haygeebaby

Yep - chip is programmed for 98RON - SW chip is great - I'm positive that the chip makes some BHP.
What dyno did you run on delanobe ?
What chip did you change to and what bhp and tq figures did you get afterwards ?

Mike J

Check out my thread when I dyno'ed my car, you can compare your car to mine..no chip, no real mods, but I had recently rebuilt the engine and retimed the cams to what I thought was the best timing. Note there can be big variations between different dyno's, but this might help as a point of comparison.

https://rennlist.com/forums/993-foru...s-through.html

The dyno chart looked like this:



Cheers,

Mike

haygeebaby

Mike
Looks like we have similar TQ numbers, but 253rwhp !!!! Dude - no mods - that's megga strong. That's 304bhp at the crank. That's 60bhp more at the crank compared to me. Are you sure you didn't accidently put in RS Cam and in-takes like SW said ?

DIY engine build hey - what scale of difficulty is that ? I consider an oil change to be about 2 on a scale of 10. My car is a 94 - so pretty dam old - 15 years - but only done 72,000km's (45,00miles) - I guess an engine rebuild does wonders. What would be the time and cost to get a garage to do that ?

Cheers

Mike J

During the rebuild, I did a number of things, including cleaning the injectors, new cap/rotors/wires, plugs, air intake, cleaned everything (including the varioram), but I think the best thing I did was advance the cams. However, everything is stock, only "improvement" was to use ARP rod bolts for extra protection.

A rebuild costs lots and lots of $$$, its not really a performance improver. Don't forget there is lots of variations between dynos, but in this case we dyno's about 12 cars, and they all were as expected, except that I was at the top of the range for my engine. Also, with a 94, no varioram so that also changes the characteristics. With only 45,000 miles, your engine does not need any rebuilding (unless its burning lots of oil).

However, its known that the 911 engines have variations, so you can, if you are fairly capable, check you cam timing while the engine is in the car (I show that in the documentation). Nice thing about a 94, its has the old style cam timing so you can set the timing manually. That will take a bit of work though...and the only result might be just a bit more low end grunt.

My dyno run was done in 4th gear, with repeated runs from just above idle to the rev-limiter. Scared the crap out of me since the room was small, and the engine fairly fresh (I was listening for weird engine noises...).

Since then, I have gotten comments from people who take my car out on how strong it pulls, so something must be right. However, no real magic, perhaps I fluked and got all the parts working right.

Cheers,

Mike

Stealth 993

This is mine from 12/20, I should say it was 21 deg out side.
Stock 95 C4 it has 87kmi.

haygeebaby

Here are the dyno's. What do you guys think ?
Putting the original chip back in and the cat back on to see what happens.

Do you have to drop the engine to do the check the timing ?

haygeebaby

Stealth
Those are good numbers as well - 255rwhp and 232tq. No mods as well hey ?

haygeebaby

So - any comments on the charts boys ?

I'm feeling better after doing some more research on dynos - found a dynojet to dyno dynamics converter - and also read that some people find around 20% differnece in dyno readings between these two dynos. http://www.to4r.com/calcs/pwtq.php

If I do a conversion of my dyno dynamics figures to dynojet figures 205rwhp and 255tq, I get around 241rwhp and 226tq. This is pretty consistent with Stealth's dynojet charts. But man - Mike - your figures on the dyno dynamics - that's really impressive - off the charts man. If you did your run on a dynojet - you'd be getting a figure of around 300rwhp.

Have booked in for another dyno this Saturday - which is Lemans day as well (yeah baby) - and will test on the same dyno with cat bypass off - and stock chip and 911chip.

Cheers

Stealth 993

It's AWHP, not rear wheel. Yea, it's stock.

However, that's uncorrected numbers, due to the cold. The corrected numbers are smaller.

Your chart looks great. Nice A/F nice normal curve. I'd say everything is normal, & the dyno #'s are just low. You really need to take another 993 on there & se what they do.

Here is my corrected chart. This kind of proves, you don't put to much into the numbers.


Mike's numbers are just as impressive, his car must pull like a freight train.

mongrelcat

Why is the torque curve so uniform and flat? Seems odd.

Also, can you just replace a chip between runs and get accurate numbers? I would think that the ECU has to sort of learn and adjust for awhile to run efficiently?

haygeebaby

Can anyone else comment on that flat torque curve ? I think my scale is different compared to the other charts. And maybe one is off a C4 and the other two charts are from a C2. Am I right ?

Yeah - with the chip changing on the dyno. I'm going to run stock a few times, then cut the battery power, change the chip, and then run it through the gears for a while, while the thing is on the dyno. You think that is sufficient or not ?

Stealth 993

First you WANT a flat torque curve!!

It's just the scale of the chart, you can see it dips a little. The scale on the side is very bunched up. Mike J's torque curve is also very flat, & that's the way it should be.

haygeebaby

See the two dips I have on the bhp curve - 1 at 3750rpm and the 2nd at 5250rpm - what do you guys think I can do to smooth it out ?

Do you think it's worth it to get cam timing done ?
Is it possible to check the timing on your own and without the engine out ?