First drags of the season on friday - need opinions
 

So the first drags of the season are on friday night, and I plan on running the car. Been tuning for a couple weeks (manually, without MLV) and the car seems to run pretty good. I do have a few issues that I will list below, but I am posting my MSQ and a datalog (if it'll do any good) to get some opinions or suggestions on things that may need some changing before friday.

I do not trust myself to change the spark settings yet, so I am still running the same map that Braineack sent with the MS when I bought it. As far as I can tell, it's been doing ok. Car is currently running ~11psi wastegate pressure, although I will be backing that down to around 8psi and using a manual boost controller to get it up to 12psi. AFR's have been in the low 11's at redline. Plugs look great, nice and clean.

Current issues:

- Car still has a slight misfire at idle. Not sure if some settings are off, or if the injectors need to be cleaned. Either way, it doesn't really bother me.

- When pushing the clutch in to come to a stop, the idle drops a little faster than I would like to below idle speed, then raises back up to settle at ~950. How can I get this to drop slower?

- Launch control! Best way to get it to work?

Thanks guys!

-Misfire at idle is probably just AFR tuning. It's tough to get right.

-Don't know on the idle settings, someone here will, though.

-LC/FFS? Do you have a 5-speed? Don't.

The Launch control is something that I will only use at the track, and do not plan on dumping the clutch when it's time to go. No plans on using flat shift, doesn't appeal to me.

I assume you've at least got a Torsen?

Nope. :) Working on that. Just an open from a '97 for now. Searching for a bare torsen lsd to install into what I already have.

If you plan to do much drag racing, you should consider the RX7 (non turbo) clutch type. It will hold up to more abuse then the torsen, and will bolt in your 1997 housing. YMMV

With how much modification? I will assume that I need new halfshafts and a certain driveshaft.

First thing you should do, is perform a search for RX7 LSD. It has been discussed Ad nauseam here.

If you are already running the 97 open differential, you have already made 95% of the modifications. Find the proper RX7 LSD, remove the center section of your 97 open diff. remove the ring carrier, then remove the pinion gear from the carrier. Install the ring gear on the LSD install the LSD into the center section (need to set proper backlash, and check pinion depth). Reinstall the center section into the differential housing (change halve shaft seals). Reinstall shafts fill with oil with friction additives.

I've been told it's not really beneficial for me to upgrade to the non-turbo differential. I'm just going to keep what I have for now. If it explodes, it explodes. Not my only car, and I have access to numerous parts. So it's not that big of a deal.

Anyway, anyone want to help with the MS stuff?

Whoever told you that upgrading to the Rx7 LSD wouldn't be beneficial is an imbecile.

LC is easy - do a search. ApexOnYou's settings is what I use.

RX-7 LSD is win. No one here is saying your open diff will explode (it won't), just that the rx-7 lsd will give you better performance in racing. I just got an rx-7 lsd and it's great off the line and out of corners. And I'm still n/a!

Ah....looks like I'm on my own here. Thanks anyways guys.

So none of the runs at the track went well. Car was faster last year with a smaller turbo and a voodoo box. :laugh: Needs some serious tuning, so hopefully I can get the car on the dyno at work this week and get it tuned. I have the fuel about right, but the spark map needs help that I can't give it. :noob:

Here's a datalog I did during my last run. If anyone wants to take a quick look and point out anything you see is weird or not cool, that would be great. Oh, and don't pay any attention to the WB02 reading in MLV, it's way off. I still need to relocate the ground for the WB.

Drag passes without a wideband, eh?

You're only making 3psi at 5000rpm and 9psi at redline. What BC do you run? You need to tune TP as you don't hit 100% anywhere. What WBO2 is in there? You accel enrich also seems untuned. Basicaly you're running an untuned car at the drags... nice!

GT, you have the greatest tuning tool known to man (well, atleast men that drive Miatas) and you're not even using it to 1/8th of it's potential. This is stuff you CAN do by yourself. Trust me, I'm supernoob too.

1. Fix the above...boost control, wideband, TPS and accel enrichments. This will seriously improve driveability, and power.

2. I don't think you're problems should be much in the department of spark. If you're running the map Scott sent with the unit, you're pretty good. Sure you can eak out another 20hp on a dyno, but mine pulls like a banshee with that map. Of course I see 10psi at 3000rpm and hold it to redline....

3. Fuel is most definitely a problem. Without a functioning wideband, you can't filter your VE table through MLV effectively. This is what the majority of a good base tune is...and should definitely be done thoroughly before hitting a dyno. If you can count how many datalogs you've run and filtered, you've still got work to do. The last one I ran was a 25 minute set of twisties that got my maximum cell change down to 4. You should be able to get under 5 for cell changes on consecutive runs. You may see a greater change day to day, so just pick a day you like with weather you normally drive in and tune away.

4. If you get all this straightened out, you CAN tune spark. I'm about to do this the hustler way. Build det cans, drive up hill with "friend" :giggle: in passenger seat...profit.

Good luck.

Wideband gauge in the car works just fine. I've been going off of that.

FM MBC, PLX wideband. Accel enrich is untuned because I don't know what to do there. :crx:

You still seem to have this down a hell of a lot better than me. I learn best by watching people do things. Trying to learn how to do it by reading takes a lot longer.

Any tips?

Something was definitely up last night, because boost was building way to sloooowww.

It's finally nice today and plan to do that. However, I have not been using MLV but am tuning by hand because of the funky wideband readings in MS. As stated above, the actual wideband gauge in the car works fine and I have been tuning from that.

Yeah, I need it.:facepalm:

MLV tuning is 100% better and faster than by hand. Get the PLX to work with your MS or get a WBO2 that will work and thus log with MS. Then learn to use MLV. Also read the MS manuals on how to calibrate your TP. Oh and pop the hood, maybe your wastegate is just loose.

I'm under the hood at least twice a day, the WG is fine. We have had issues with the WG actuator that I am using, so I may switch that. I plan on re-grounding the WB today.

GT3

Sorry, would have been more specific, but have been at work all morning.


WIDEBAND:

I'm not familiar with the PLX, but with the LC-1 you first setup the WBO2 controller to give your linear output based on the controller lambda values. An example is a 0-5V output for corresponding 10-20AFR values. This means you have about 2.35V going into the MS for a stoichiometric 14.7 air/fuel ratio.

Fix this first, and be very very happy, because MegaLog Viewer is THE ONLY WAY TO GO with regard to a street tune on fuel. Leave the hand smoothing for later, or for the load-dyno operator.

TPS:

Check the drop down menus. Sorry, am at work now, but there is a calibrate option on one of them that is hella easy to use. I could talk you through this, but didn't have time to put my BMW unit on this week. If you don't have it done by Tuesday, PM me, as I should have it figured out. If you search there is a write-up on this.

ACCEL ENRICH:

These are in the basic settings, and you have the option of "map dot" or "tps dot". Since you're running tps, use the second option, and tune the (3) little fields that are there. These aren't a function of req-fuel, so if you haven't changed them since you put in the bigger injectors, you REALLY need to do so. I just went in and cut all the numbers in half (since 460=2x230) and this fixed my backfiring and decel popping issues.

I'm not sure if you'll have to start from scratch for TPS dot, but it's easy to tune, just pick some nice numbers, say 3-5-7, and go down 2, then up 2, for each, and see which direction is getting you closer.

BOOST CONTROL:

Sorry, can't help you here. I just know a lot of folks have trouble with EBC and MS. You may wanna go wastegate until you sort out the more basic problems. I imagine this will only compound issues right now, and make it harder to diagnose symptoms.


When I'm back in front of my own PC I'll try and get you some screen shots, but you should still have my .msq from the other thread (please don't run it) if you want to check your spark table. I've changed just about everything else since then, but have not TOUCHED that spark table, and I can't say my car is slow.

I made a G35 look like the Buick it is last night.