It's Alive! Finally Dyno Tuned!

98CobraStarLSC

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Finally Got the Mark VIII Dyno Tuned at Logan Motorsports. I got a SCT Xcalibrator2 and had Logan see what they could improve on..:rolleyes:

So, as it was, before hooking up the xcal, i asked if they would do a dyno pull just as i had it, when they did, the air to fuel was soo lean that he didnt feel like it would be a safe pull so he stopped it at around 4000 RPM. For some numbers, the a/f ratio was at a little over 16:1. for those of you who dont know, it should be, depending on the tune, around 13:1 ish...
I was reallly suprised.!!

After the tuning, it ended up putting down 239RWHP and 245RWTQ. It was still making power all the way to 6000rpm(where the dyno stopped) he said at 6500rpm it makes 243-248rwhp..It was about 80 degrees in the shop. I had the shift points raised, Shifts Firmed up! Which was a HUGE difference. Cooling fans come on around 180 now. along with some other things.

Heres a graph of one of the pulls. As you can see, the torque curve is nice and flat, So for everyone who had questions about running a short runner cobra intake, You don't Loose the low end .. Just goes to show, unless someone has done it, then nobody really knows for sure. i had soooo many people tell me that it would be a dog down low even with the 4.10's, grant it that i am still running the imrc's..



Overall i am REALLY impressed with the numbers considering on their dyno, (which they told me early on reads a little low), that the gen 2 marks were running from 205rwhp to 212rwhp.. so to be conservative, i gained about 30 wheel horsepower from the mods in my sig.. Very impressed. heres a video of after the tune 0-85..
http://www.youtube.com/watch?v=80W0h2lea1k

and lets not forget the before the tune video i posted. you dont need a timer to see that it is way slower here!
http://www.youtube.com/watch?v=ZMGr-88Ql4c

anyone got a stopwatch? i would like to see how my 0-60 and 0-80 changed between the two videos!

Comments please. Be honest!
 
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yes, big difference! Thanks guys. The project has been really great so far, i cant wait to get some Really Big numbers down, but it should pull a decent time at the track...

Ill be happy to answer any questions anyone has about the mods or anything about the car, happy to help!
 
yes, big difference! Thanks guys.
Ill be happy to answer any questions anyone has about the mods or anything about the car, happy to help!

what kind of rpm are you running at 70?

how much time and money do you have into that intake?all together.

how much did you spend on getting the gears in?
 
what kind of rpm are you running at 70?

how much time and money do you have into that intake?all together.

how much did you spend on getting the gears in?

RPM at 70mph is around 24-2500rpm.. its really not bad at all, i expected a lot worse! I only lost 1-2 miles per gallon on the highway! That is really what suprised me.!

As for the Intake manifold, i bought it from this forum actually!. heres the link, http://www.lincolnvscadillac.com/showthread.php?t=41670&highlight=cobra+intake.. It ended up costing me $350 shipped. (as you can see he said it should be 40whp, which i completely didnt beleive but i just wanted a cobra intake) It was worth it, usually on ebay they run $275ish.. It was recommended in the writeup that you do the cobra fuel rails, i didnt, i used the stock ones. I would recommend getting the cobra rails because of the low cost as opposed the the large amount of modification that has to be done to the cobra intake to make it fit.(you have to cut around the fuel pressure regulator and other areas to make it fit. I spent another $200 on the C&L intake and maf used off of craigslist.

As for the 4.10's install, i do all of my own mechanical work, (i work as a technician at Carmax). So it didnt cost me anything except parts($550ish) i bought them from Max at five star = best deal around period... But i did get a couple of quotes to get them installed just to humor myself. They ranged from 400-700 if you have EVERYTHING including the oil. We have independent rear suspention which means a lot more work, but in my opinion, its better. It took me about 12 hours i think, taking my time and going to breakfast, lunch and dinner . Mind you that i did it ON THE GROUND with jack stands. Find a lift, its a pain on the ground.

Hope that helps.:)
 
Why so lean before the tune?

Nice pull on the dyno, now on to the track! :D

I was running all stock ECU values with a check engine light. but i had all the mods to the intake was causing way more air and no more fuel!. i have the conical filter, cobra manifold with direct runners, and ported throttlebody..

Thats crazy that it was soo lean right? i was very suprised!
 
C intakes are pointless imho unless your boosted or have monster gears and a huge converter. I have never seen major dyno gains from one, looks cool though and make s a sc a direct bolt on too.
 
cobra intake and everything for the rear end 4.10's was all together about 1000! not bad but you have to do the install yourself for that price!
 
Good stuff! Just a quickie... is the race weight in your profile a typo?
 
another comment on the 4.10's... Everyone said with the xcal2 you could compensate for the rear end gears and get the speedo right?? They told me no, you couldnt because it uses a manual type speedometer sensor?

But when i am on the highway and around town as well, it doesn't seem like the speedo is off? seems like i flow with traffic great like it was back in the day with the stock ones. Weird huh? i have yet to test the true speed but i think its spot on..?
 
i am thinking that you have an exhuast leak pre-sensor for the wideband. 16:1 is so lean you would be melting stuff down if it was even acclerating at all. you usually get bad surging with 16:1 or leaner at a cruise state, much less a WOT pull.
 
No, not an exhaust leak...
well, they told me that it was so lean that my Check Engine light was from the O2 sensors reading sooo lean.. we checked and they are working perfectly. I have stock o2's they took mine out and put in the one for the dyno readings.. Basically the o2's were reading so lean that the computer was having to try to compensate..

Must not have explained well enough, to run on the dyno, you have to put the programmer in so it can be held in 3rd gear(1:1) .. so he plugged it in and the computer thought the problems were fixed because the check engine light was fooled into turning off. THAT is where we got a 16:1 a/f ratio. And yes it was surging like a M.F. when he gave it throttle.. haha. but just plugging in the programmer to hold 3rd gear and turn off the light, with the base map, it read a very lean 16:1..

Hope that explains, even reading it makes me even more confused. haha its hard to explain..
 
NICE :D ......Gen2's read from the ABS for the speedometer, the trans is the one that needs to be adjusted for the change in gears.
 
NICE :D ......Gen2's read from the ABS for the speedometer, the trans is the one that needs to be adjusted for the change in gears.

so is my speedo right or do i have to get into the Xcal2 and change trans ??? please elaborate and thank you!
 
so is my speedo right or do i have to get into the Xcal2 and change trans ??? please elaborate and thank you!

On Gen2s the speedo is of the ABS like shiryu0 Said. Your speedo should be just as accurate as before. IIRC the only thing you need worry about with the gear in the trans is the freeway ride height speed is picked up off of it. So without changing the gear in the speedo the car will drop at a lower speed.
 
I thought it was very close! But i didnt know about the ride height.. thats some good info!.

Also, i have a 160 thermostadt and i am programming my hi/low speed fans..

what should i set the low at ? and the high? (in the x cal2 )

It was defaulted at low 198 high 208 which is for the stock one.. the stock t0stat is a 188 degree.

EDIT- heres a picture of the intake with the cover off during installation.. For those of you who pm'd me asking about it


Rich, do you have some vis of your 3500 stall????
 
Thats crazy that it was soo lean right? i was very suprised!

but just plugging in the programmer to hold 3rd gear and turn off the light, with the base map, it read a very lean 16:1..

I always thought the base maps were excessively rich. Usual intake mods will result in leaner mixtures than base but are soon compensated by the PCM. Sounds like that's what was happening.

NICE :D ......Gen2's read from the ABS for the speedometer, the trans is the one that needs to be adjusted for the change in gears.

Isn't the TSS is still used by the PCM for shift programming independant from the speedo on the Gen2? Stock that is - with the XCal programmer the shift points are programmed to the desired results.
 

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