1. 2003 Ford Mustang GT
2. Ease of install: 5
3. Instructions Provided: Yes (though I have some revisions to them)
4. Overall Satisfaction: 10
5. Where you purchased the item: http://www.mustangtuning.com

 

SLP LT's are definately worth every penny. I'll start off by talking about the installation. Me and my dad installed these back in April 05 in our small 1 car garage at home. Since then I have received countless PMs and emails with questions about the installation, quality, and results. These were installed along with the SLP Short O/R X-pipe and Steeda Cat-back. We started the installation on a Saturday night with plans to work on it the following Sunday and hopefully have it completed by then. That didn't end up being how it worked. On Saturday night we removed the stock H-pipe and the manifolds. We also removed the starter and moved the steering column out of the way (make sure the battery is disconnected if you remove the starter).

 

 

The next day we started with installing the LTs. At this point we had been following the instructions provided by SLP. We started with the driver's side. It was kinda interesting. My dad lay on the floor holding the header while I stood over the engine on a step ladder trying to hold it from the top while he tried positioning it to bolt up. This is the point where if I had video it would've been heavly censored because every other word was a curse word from either one of us. We kept trying to get it to work but the EGR valve was also giving us problems. I think we managed to get 1 or 2 bolts in but then the EGR tube would not connect to the header. We couldn't get it to work around and it kept hitting up against the firewall.

 

We then tried the passenger side header. We could get a lot of the bolts on that side, but there was 1 that we definately could not reach. At this point we decided to throw out the SLP directions (which said that they could be installed easily this way) and we decided to drop the k-member.





In other people's pictures I've seen who have done the install themselves and dropped the k-member they completely took everything off the k-member and moved it out of the way. Well we had 2 floor jacks (one is older than I am) and a motorcycle jack, so we just dropped it and raised it back after the install. With the k-member out of the way and the suspension there was so much more room and installing the headers became SO much easier.

 

I used the gaskets and bolts that were provided by SLP. Well one of the gaskets was destroyed when we were trying to install the header with the k-member still up. We found some that looked almost exactly like the ones SLP provided at Autozone.



After this we were able to go ahead and finish the install of the x-pipe and cat-back. The process took 3-4 days. On Sunday when we started to try to install the LTs we gave up half way and my dad had to go paint a car. We continued on Monday with dropping the k-member. We actually didn't finish until Tuesday because the instructions for the cat-back provided by Steeda were completely flipped flop and wrong. We didn't work full days, just a few hours each day.

As far as the results go.. the first time I test drove it I noticed two things. The first thing I noticed was the decrease in the lower RPM range. It made daily driving easier but you would definately have to downshift to go anywhere, it was a pretty big different. The second thing I noticed was when I got on it. At 4000RPMs it felt like a completely different car. You could feel the increased power at 4k for sure. Of the mods I've done it's definately one of the more noticeable increases of power. Probably about a week later I took a guy I work with for a ride. I was still using stock tires at the time and it was pretty cold. But I remember that I was driving normal and I got on it.. everything was fine until I hit that 4k mark and then the car actually lost traction and tried to get sideways it was pretty impressive.

Some possibly negative things I've noticed is that there seems to be a bit more noise coming from that area. Which this maybe the installers fault.. normally you want to put the dipstick back in as soon as possible, we forgot to do it until last. Well we couldn't get one of the bolts for the dipstick back in so it sounds like something is kinda rubbing.. I've always sorta assumed it might be the dipstick rubbing the header. The other issue is that it sometimes seems hotter inside the car around my feet lol. The other downfall is the loss of your downlow power.. which bring me to my next recommendation.. a tune. It wasn't for a few months until I was about to get it on the dyno and get it tuned but it was definately worth it.

My dyno results... I headed down to Memphis, TN to DynoSpeed Racing (which I highly recommend) to be tuned with an SCT Xcalibrator 2. My mods at the time included the SLP LTs, SLP O/R X-pipe, Steeda Cat-back, Accufab 75mm TB and Plenum, and Steeda CAI and my car is a 5-speed. My first run before the tune was 257 rwhp and 284 rwtq with SAE correcting. The results weren't bad at all, but they showed I was running about 18-20% lean, which is never a good thing. So in the tune they decided to give me some more fuel. After that my final numbers ended up being 270 rwhp and 306 rwtq. The best thing about the tune was that it added A LOT of downlow power that I had lost out on. I gained 30-40 rwhp and 40-50 rwtq around 3500 RPMs.. it made the car feel soooo much stronger plus the extra horsepower and torque is always a bonus

 

As far as how loud it is. They say it's a common myth that LTs make your car louder at idle, I couldn't tell you if it's true or not since I installed all my exhaust at once. But I have been told it sounds quiet.. except at WOT. I actually have a video of me and a c5 vette beside me, and a LT1 and LS1 behind us all going WOT.. and the whole time you can hear my exhaust over all of them, and they also have aftermarket exhaust that sounds much louder than mine.

Anyways.. this just about concludes my book on LTs lol. Sorry for any errors!

Here's a video of the install and some other clips to just hear the car

Exhaust Install Video

Just a WOT video