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Discussion Starter #1
Hello all! I've recently acquired a 1993 Mark VIII and I've been making some videos about getting the car running and driving. You can check out the latest video here:


I'd like to know what sort of modifications you'd like to see, we are going to try to test all of them meticulously. I'm not that familiar with this platform, so if you have any modification tips let me know!
 

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Cool!
As far as dyno testing, I would love to see a dyno test of stock vs 96-98 Cobra cams, and then the cams installed straight up vs degreeing them. I would also like to see what deleting the IMRCs does, both to the top end power and the overall curve.
Another common mod on those is some 4.10 gears, since they are kind of lacking in the low end torque that helps get the heavy car moving.
 

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Discussion Starter #3
So we've already purchased a set of '01 Cobra cams, I was looking around for a set of '98 Cobra cams but they seem to be getting more difficult to find. The '01 Cobra cams were VERY cheap and local. I plan to dyno test them as installed and then degree them and re-dyno.

As far as IMRC goes, we will likely test them by commanding them open all the time or closed all the time in the tune to see what exactly happens. We may do a IMRC removal test at a later date, but my experience with these engines is that taking the IMRC out is a bad idea on a mostly stock engine. When it sees boost we will remove them though.

To start out we are going to do exhaust modifications, I can't believe how bad that stock exhaust is!
 

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Sounds good. I actually ran into the same issue. I'm building a budget C-head 4V to swap into my 97 Tbird, and I couldn't find the 96-98 Cobra cams anywhere, but I got a complete set of 99 Cobra heads with cams locally for $200.

For the exhaust, check out these guys.

Their exhaust for the 92-97 Tbird will fit the MarkVIII with very slight modification. Basically it hits the MarkVIII gas tank where it goes around, so you have to extend the pipes in that section slightly more to the driver's side, and then it will fit.
 

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1994 Cougar XR7 DOHC/5-Speed
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On a 93 the exhaust should fit identically, the tank changed to a steel design on 97-98s for whatever reason, and that’s where the routing issue comes from.

I lucked out on my 96-98 Cobra cams, I paid $250 for the with stock heads(which are still in my basement). The cat was out of the bag when I was looking for them, they used to be a $100 low budget upgrade, pretty crazy seeing people listing them now for $300-400 for 14° of extra duration on the intakes, 01 cams are plentiful since Continentals used them and are only 4° less
 

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95 t bird lx 95 dohc mark viii engine 98 rebuild trans jmod med stall
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I just order the exhaust from those guys all ss including the front wish comes with x pipe . just letting you know.
 

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1997 Thunderbird 4.6, 1998 Mark VIII LSC
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Fairly typical numbers IMHO for a basically stock FN10. It's nice to see it running strong even after 27+ years. From a personal curiosity standpoint I'm assuming the pulls were done with 91+ octane fuel? It would be interesting to see how much the curve changes when running 87.

I have one of the Trubendz systems on my MN12 - given the fitment issues I had with their first design and how much they worked with me to get the second design right, I can recommend them. :)
 

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Discussion Starter #8
226 rwhp surprises me on this dyno. A stock '01 Cobra makes ~250 whp and a stock '04 Mustang GT will make 200-205. A stock '91-'93 5.0 5-speed car will make ~170 whp. It's pretty strong.

The pulls were done on 87 Octane, these motors just don't have enough compression to need 93 Octane. I've never seen it make any power on any naturally aspirated 4.6 regardless of the year or type. Coyotes will make a bit more with 93, but not the 4.6 motors in stock form. I've dynoed at least 400 4.6 powered Fords.

I think we are going to go with the Trubendz system, were were going to fabricate a crazy 3.5" single exhaust just for kicks but I'm not sure it's worth the effort with those being so affordable. We are going to do something fun to replace the exhaust manifolds on the cheap, it'll be cool!
 

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1997 Thunderbird 4.6, 1998 Mark VIII LSC
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Actually the tune for the Mark VIII is written for 91. There are knock sensors that pull timing if it's run on less than 91. I run 87 too because it's not worth the extra few HP/miniscule extra MPG for the 30-40% price premium of premium around here. Hence the comment. :)
 

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1994 Cougar XR7 DOHC/5-Speed
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I‘ve been running mid grade 89 lately and haven’t noticed any evidence of pinging, and I haven’t even pulled timing from the 93 tune I loaded into it two years ago, that has definitely made me curious about tweaking the tune and running 87. I can tolerate a car that guzzles fuel @17-18 mixed MPG for what I deduce makes about 265whp for the visceral fun of it, but not so much that 40% premium anymore.

Edit: it just hit me, are you the same LoganD from the corner-carvers forums?
 
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