Diablosport Forums

I installed the predator (u7146) latest revision r09 and I have been really impressed with the tune so far. I did a 93 tune and am using 91 octane (I took 2* from the spark advance to accommodate this as per the forum remedies). I have a K&N intake, magnaflow exhaust and this tune so far. I have noticed a lot more torque and hp since I made these three mods about 2 weeks ago.

The only thing is that I have an automatic trans and when it goes from 1st to 2nd it goes up to 6000 rpm and slams it into gear which causes the rear wheels to break loose at like 50 mph and I fishtail a little (this is with traction control off). I was thinking that if there was some way to shift easier or at a lower rpm (~5800 or something) it would allow the rear wheels to catch after the shift and improve the acceleration instead of peeling out. Would you recommend that I try to lower the 1-2 shift point or should I mess with the shift firmness instead? It is a little scarry because I only thought I had like 300 HP now and it feels like a lot more. It is making me wonder whether I should continue to add bolt-ons because this is a lot more power than I am used to and I dont want to lose control of the vehicle during fishtail. Otherwise this tune has really improved the acceleration and it is a different car than when I had just stock items. Thanks in advance.

Try lowering the firmness, but better yet, look into some better tires!!!

same thing here and have nitto nt555s and it still does it.but i only have gears and tune.i cant wait until the catback goes on and the pulleys.just installed the jlt ram air on it today

I have the goodyear unidirectional eagles that it came with which are in pretty good shape. I did lower the tire pressure to 30 psi in each tire down from about 36 and that did seem to help a little. In the last few weeks I have got used to the acceleration and I want more now haha! I am going to add bbk shorty headers and a 75mm throttlebody and plenum kit and that should add about 25 more. I think i will take it to a custom tune location in my area for diablosport and try a dyno tune after that. I hope that allows me to hit somewhere around 320 rwhp. If that is not enough then I am going to try out a vortec supercharger because my goal is to get it to around 450 rwhp. This little stock looking automatic GT is going to eat up everything it sees...including cobras and riceburners!

Jdoggers wrote:I have the goodyear unidirectional eagles that it came with which are in pretty good shape. I did lower the tire pressure to 30 psi in each tire down from about 36 and that did seem to help a little. In the last few weeks I have got used to the acceleration and I want more now haha! I am going to add bbk shorty headers and a 75mm throttlebody and plenum kit and that should add about 25 more. I think i will take it to a custom tune location in my area for diablosport and try a dyno tune after that. I hope that allows me to hit somewhere around 320 rwhp. If that is not enough then I am going to try out a vortec supercharger because my goal is to get it to around 450 rwhp. This little stock looking automatic GT is going to eat up everything it sees...including cobras and riceburners!

Dream on dude, your gt came with around 240 to the wheels... All the bolt-ons you can buy will get you to around 255 to 260 if your lucky. LT headers and supercharger, turbo, nitrous is all you can do to make the 2v decently quick. Still only looking at 350 hp to the wheels.....which will never come close to a stock cobra...

Stock automatic GTs typically would dyno at around 215 RWHP. With your catback and intake, you've probably gained 7-10 peak horsepower over the stock 215. With short tube headers, a plenum and throttle body, you'll add another 10-15 rear wheel horsepower - all in all, when you are done with these mods, you'll be in the 235 RWHP range. With that said, you'll never touch a Cobra, stock, wounded or otherwise - they dyno at around 360.

I'd suggest LT headers (short tube or long tube are both difficult to install - might as well go for the best while you are in there), 4.10 gears and a centri supercharger. That's the best bang on a budget. Then you might be able to hang with a stock Cobra.

Without a budget, I'd pull the motor and put some serious slugs and rods in there...might as well add a Cobra crank (even though the OEM crank is not likely to fail, it's one of those "while you are in there" situations) and some free breathing heads, then add a Kenne Bell Twin Screw Supercharger and explain to 04GTMike that the 2V motor isn't so bad after all.

And by the way, I don't own any GTs any longer, but I think the 2V is still a good motor. (But I love my 4V now, even though it has the crappy rods and pistons like the 2V. Still, with midpipe, catback, underdrive pullies, cold air intake and Diablo Predator tune, I only turned the dyno to 303 RWHP.)

Ok, so you basically told him the exact same thing I did...but with more detail. Why would you pump all that money into modifying a 2v when you could swap in an 03-04 cobra motor for less than all that? Basically I just wanted to clear up the disillusionment about the horsepower from bolt-ons. I have a 2v and im struggling about what to do with it. I say n2o if your poor, procharge if you have money....and just deal with it until you can save up for a cobra? haha.

Because some people will never be able to get into a Cobra, but they can afford a 2v and just add bolt ons as their budget allows. I wouldn't consider the 2V as simply a stepping stone. Some people are quite happy with their 2Vs and have made big power.
Also consider that you can snag a 99-04 2V for 7K - 11K. An 03-04 Cobra? Try 20K.

Swapping in an 03-04 Cobra Motor? Not so cheap, not so plentiful.

We both certainly agree on the validity of 2V bolt ons - on an otherwise stock motor, the gains are typically minimal. The biggest issue is the heads.

I stopped buying bolt ons for my 2V (the dollar value is simply not there) and was saving for a Kenne Bell, but then I got the itch to go fast and bought an NOS direct port Noszle kit - it was a blast with a 125 HP shot, but then my car was totaled a month or so later (thanks to an unlicensed idiot).

But understand that some people would be totally satisfied with a supercharger on an otherwise stock 2V - pumping out 350 RWHP. That's quite fast enough for a lot of folks. Together with the price of a an average 2V, you're talking about somewhere in the $14K range.

If that's not fast enough, add pistons and rods, fuel upgrade and crank up the boost. 450 -500 RWHP is easily obtainable on a 2V with a forged bottom end. Total additional investment (with stage 1 already in place) - circa $3-4K. That's well under $20K for big horsepower.

I would just step up to a cobra, financing is your friend. Why throw all this horsepower into a car that was never meant to have it? Cobras going for under 20K here, even 20 isnt bad for a badass car putting down almost 400 stock with no need to mess with anything. Finding 4v cobra engines is not hard at all, know someone who has built 4 "fobras" already with great success. All depends who you are, what you can do by yourself without paying someone to do it, and how much money you have. If you love your car and need something to do, then hell tear it apart and build away and still not make much power. Or just take it for what it is and step up to a faster car stock and make it hella fast. but yes, bolt-ons will only do so much and will not have you beating cobras or vettes or even the 3v for that matter.

I'm not sure I follow your logic with the statement, "Why throw all this horsepower into a car that was never meant to have it?" Actually the solid axle in the 2V is superior to the IRS as far as handling the power and getting it down to the ground. As I'm sure you know, this is exactly why Ford returned to using a live axle setup with the new Shelby Mustangs. And that's a shame. To see the Corvette doing it right with their IRS, yet the Ford product struggles with the same configuration is disheartening. I love my Mustangs, but I'd jump at the chance for a ZO6!
Otherwise, the Mustang chassis, 2V or 4V, is nearly identical. And you'd quickly drop a 4V Cobra motor in but you won't build on the 2V motor to get the same amount of power? I don't understand why you feel that there is a difference. (there is the trannie as well, I'll admit)
Anyway, we could go back and forth on this, and it's all good Mike, just different views on how to spend money and how to go fast. The bottom line is - the original thread starter is WAY OFF in his estimate of RWHP and gains obtained with bolt-ons.

I just meant boosting an engine that wasn't built to handle it, and opening up an engine when can have a factory proven already boosted engine just dumped in. And yes the tranny. Many paths to take, but were all trying to get the same thing. All my cars have to end up being daily drivers also, so I can't have them take a sh*t on me either. I kick myself for not getting the mach 1 I could have gotten, but at this point a lightning may be in my future. Nobody tells you buying a house means you should also buy a truck haha. It's all good though, only reason I commented on here was to slap some reality into someone who probably isn't even reading this thread.

04gtmike wrote:...It's all good though, only reason I commented on here was to slap some reality into someone who probably isn't even reading this thread.

True, True...

I don't think it is a waste to mod a 2V but if you want 500RWHP, sell it and buy a used 03/04. In the long run it is cheaper. Everyone looks at it fom the view that, "i can get a GT for $10k with low miles" then add a built motor, SC, a transmission, etc..etc. Then you have have $20k+ and it is still a GT and worth no moe $$. I'm not knocking the GT's, perfect if you just want around 400rwhp and no more.

Jdoggers wrote:I installed the predator (u7146) latest revision r09 and I have been really impressed with the tune so far. I did a 93 tune and am using 91 octane (I took 2* from the spark advance to accommodate this as per the forum remedies). I have a K&N intake, magnaflow exhaust and this tune so far. I have noticed a lot more torque and hp since I made these three mods about 2 weeks ago.

The only thing is that I have an automatic trans and when it goes from 1st to 2nd it goes up to 6000 rpm and slams it into gear which causes the rear wheels to break loose at like 50 mph and I fishtail a little (this is with traction control off). I was thinking that if there was some way to shift easier or at a lower rpm (~5800 or something) it would allow the rear wheels to catch after the shift and improve the acceleration instead of peeling out. Would you recommend that I try to lower the 1-2 shift point or should I mess with the shift firmness instead? It is a little scarry because I only thought I had like 300 HP now and it feels like a lot more. It is making me wonder whether I should continue to add bolt-ons because this is a lot more power than I am used to and I dont want to lose control of the vehicle during fishtail. Otherwise this tune has really improved the acceleration and it is a different car than when I had just stock items. Thanks in advance.

If you want as much Torque at the Rear wheels as you say, I highly recommend getting a PI 3disk 2800 to 3000 stall stallion torque converter. You'll get approx 40% more to the rear wheels. I noticed a HUGE difference !

i have an 09 gt,dyno@278 rwhp only mods are flowmaster,ford racing cai,using the steeda 91 octane tune.(u7145)tried all the tunes in the predator this gave the best result..oh and flipping the spry(n20)100 hp shot puts me in @368 rwhp.hope this adds to true dyno results..dyno'd 5-7-09