Convertible times/MPH?

[SVTCobra306]

Checked the timeslip thread, it doesn't really list if any are convertibles.. My wife's 97 vert seems slow for a Cobra. Last night it ran a best of [email protected] mph. Previously it ran 14.79 at 95.xx, both were with me at the wheel. It weighs 3488 on my Longacre scales, and I weigh about 200.. Mods in the 14.79 run were DeMolet Tunable Induction, welded in Flow's, SCT Xcal with DeMolet's canned tune, and a King Cobra clutch, otherwise it's stock, and I had cleaned the IMRC's and replaced the injectors with fresh Ford Racing 24's shortly before that run.

Last night I ran the 14.70, and the only changes to the above mods were adding a UPR catted X pipe, replacing the MAF which went bad with an 03 GT MAF and reworking the tune mostly to correct the MAF transfer function for the new MAF and delete the rear 02's. Granted, 2 MPH and nearly a tenth from two small mods isn't bad, but this thing is off the pace a little I feel.. I know I can get 2 more tenths out of it in the 60', maybe 3 without changing tires. Last nights short time was 2.3, the previous run was a little better at 2.2, and I've gotten 2.0's out of street tires plenty of times with my 94 so I have time there.. but still 14.40's would be off the pace for a modded 4V I think... IMO it should run 14 flat at about a hundred MPH with its current mods, and better with gears (it has stock 3.27's in it now).


Sorry this sounds like a rant, I guess I'm looking for a benchmark to check this car by... anyone have a stock or similarly modded convertible lol? Maybe I'm just overthinking it.. the MPH/weight suggests 275ish RWHP..

 

[PSUCOBRA96]

car is def. off, prob the canned tune isn't helping, but then again neither is your 60ft, but the MPH seems a little low as well. Get it on the dyno or to a tuner to see what he AF is and what its doing in all RPMS, whens the last time the fuel filter and wires were changed, along with plugs make sure they are gaped at .054.

what RPM are you shifting at?

 

[SVTCobra306]

I'm shifting at 6500, stretching the gears a bit so I don't have to shove into 4th at the finish..

I have plugs for it, to my knowledge they've never been changed in the car's 120K mile life.. the car runs perfectly smooth, no spits/sputters or hesitation, and you can feel the IMRC's kick at 3250. I'm changing them soon, and I'll ohm out the plug wires while I'm at it. I have to remove the intake again for a gasket that's sucking just a bit, I guess they hardened along their life, I had to replace the upper plenum gasket too when I did the IMRC cleaning. It's tempting to delete the IMRC's while I'm in there just in case they aren't opening fully.. I tried ditching the tune before, it's a tenth faster with it than without. The clutch isn't slipping. The heat and humidity last night didn't help I suppose.. prolly another MPH or two in good air lol. I'd simply think it should turn 99-100 bone stock, that's why I was looking for stock 'vert times..

 

[Wynn]

It don't sound that bad, honestly. You're probably leaving .2 to .3 in the 60'. I think the verts were like 14.2 stock, so you're there. Just do a few mods and you'll see bottom 13s. Just my opinion..

 

[PSUCOBRA96]

yeah change out those plugs, even if they look good, if they are old they may not be putting out enough spark for complete fuel burn, sounds like you might not be getting everything outta the car at the top end, play with your RPM shift time and see if it gets better or worse if you raise it or lower it by 200 rpm you shouldn't have to worry too much about shifting into 4th with the stock 3.27's, just take it to redline once your in third

 

[SVTCobra306]

It don't sound that bad, honestly. You're probably leaving .2 to .3 in the 60'. I think the verts were like 14.2 stock, so you're there. Just do a few mods and you'll see bottom 13s. Just my opinion..

I have underdrives for it.. techically they're for a Mach 1 but I also have a Termi water pump so they'll work once it's changed too.. I know gears and DR's alone will put it solid in the mid 13's.

 

[Wynn]

What were your 1/8 mile times? That's all I can really relate to. FWIW, my car would trap about 80mph in the 1/8 with the 3.27s and street tires.

 

[JSPajak]

My stock 98 convertible went 14.06 at 99.7 MPH. I was leaving at 2000 RPM and granny shifting at 6500.

 

[SVTCobra306]

Got it to 14.54 at 97.8 with just a spark plug change, 60' is still 2.23 leaving about 1500 and wheel hopping (old bushings gotta go lol), didn't get the density altitude but it was muggy as hell tonight so I think we're getting closer to where it should be. Oh and tires are now 255 Sumitomos on 17X9's instead of 245's on 17X7's lol.. not much difference but a little.. got almost a tenth on the 60' from them.

 

[Quin]

Try shifting higher.