Just Dyno'd, need advice

[97cobratiny]

Dyno'd the Cobra for the first time yesterday and put down 275hp and 271tq. I don't have a scanner but my ol' lady is gonna scan it a her work tomorrow, so I'll post it up then. It has a nice curve and peaks about 5500rpms. I'd like to make 300 to the wheels my goal and I'd like to keep it under $500. Here's my short mod list, and would love some advice on what's the best bang of the buck to get me there. The only "HP" mods are, offroad h, flowmasters in the stock cat, and a JLT CAI. I do also have an alum. flywheel and driveshaft that I'm sure free'd up a few ponies but thats about it. Thinking either short runner intake but then I'd need a tune too, right? Or maybe long tubes, but then I'd have to get a new midpipe too, and I've heard they are a pain in the ass to install. Thanks in advance.

 

[F8L BYT]

Dyno numbers are overrated but if you want 300 and have a max of 500 you will be hard pressed. I know lt's and o/r mid pipe will be more than that and im not sure but i think a sr will be also. Dont worry about the numbers so much and go with the Seat of the pants feeling and get some gears installed instead like 4.10's or 4.30's

 

[PSUCOBRA96]

500 bucks is not going to get you to your numbers, not trying to be mean, but to get to the 300 mark you will need a combination of two things such as a tune, longtubes, and say pullies might get you there. I did it with a shortrunner, lontubes, and tune with some still left on the table if I did pullies. Longtubes will get you closer but oyu are gonna still need a tune to maximize it.

 

[goat-ee]

Used nitrous kit would be the cheapest way to 300+ rwhp, and in fact would be that number to death pretty easy!!

 

[97cobratiny]

Can't get the scan of the dyno to load to photobucket so this is the best I could get, and the small dips in the run is from the dyno equipment not my car.

 

[luke87gt]

It's refreshing to see someone post SAE numbers once in a while and not try to inflate their numbers

Next, the dips in your graph are not dyno equipment. They are power dips that stem from Spark Advance being pulled, possibly due to the knock sensors. If you data-log your spark advance, you will see it dipping exactly at the same points on the x-axis (RPM-Axis) as where those power dips occur.

Next, you can get >300rwhp with less mods, but I would do the following:

- Full exhaust (1 5/8" Long-tubes, 2.5" Mid-pipe, 2.5" catback)
- JLT Intake
- March FLuidamper with larger water pump pulley
- IMRC Deletes
- Short Runner Intake
- Tune

You should see well over 300rwhp with that combo. I don't know of anyone that has made 300rwhp SAE with short-tubes, but it is certainly possible with all the other mods listed.

 

[19mustang95]

longtubes/new midpipe minus selling you old midpipe should be less than $500

 

[97cobratiny]

Thanks for the info, now where are the knock sensors located, and how hard are they to replace?

 

[pacific4v]

Thanks for the info, now where are the knock sensors located, and how hard are they to replace?

I don't think it's a matter of your knock sensors being bad as much as it's the factory tune doing it's job and pulling timing. I'd do what every one else is suggesting and get L/Ts and a psr intake, then a dyno tune to maximize your power by advancing timing and adjusting a/f ratio....oh and gear it if you haven't yet....

 

[luke87gt]

Thanks for the info, now where are the knock sensors located, and how hard are they to replace?

They look to be working just fine, lol.

When the knock sensors detect detonation/knock, the PCM then pulls timing to address it. FYI, my dyno graph looked very similar to yours when I first dyno'd. It had spikes just like that that coincided with the dips in Spark Advance.

Finish your mod list and get the car tuned. Many tuners end up turning off the knock sensors for NA applications.

Cheers,
Luke

 

[na svt]

by the look of that curve you may have a mark 8 longblock.

 

[97cobratiny]

by the look of that curve you may have a mark 8 longblock.

Is that a good thing or bad? What pros and/or cons are there with the mark 8 longblock? Sorry if these are dumb questions, but I really don't know the differences.

And thanks guys for all the help

 

[na svt]

Is that a good thing or bad? What pros and/or cons are there with the mark 8 longblock? Sorry if these are dumb questions, but I really don't know the differences.

And thanks guys for all the help

Mark 8 intake cams have 20 degrees less duration than those in the cobra. The low duration may be the reason your power is peaking at such a low RPM.

 

[97cobratiny]

Mark 8 intake cams have 20 degrees less duration than those in the cobra. The low duration may be the reason your power is peaking at such a low RPM.

I was wondering about that, I thought it would peak out in the low to mid 6000rpms, 5500 seemed low to me. Not sure what I'm gonna do next. I'd love to take a Teskid block, throw in some Manley internals, some C heads, and my buddy's Eaton he took off his twin turbo 04. But that would cost a bit more than I'm willing to spend right now. NA SVT, the modular master, what advice would you give?

 

[MouTine]

Many tuners end up turning off the knock sensors for NA applications.

Cheers,
Luke

I would like to read more about that? Is it realy common? Any more info particulary how you tune it off? I'm askinf couse I have Moates chip and friend of mine can do tunes to that chip.

 

[na svt]

Turning off the knock sensors is very common and should be done whenever max performance is wanted.

$500 buck will get you very little power gain. Get a short runner intake for an additional $150 you'll pick up 15-12rwhp. Headers will provide a small gain, 5-10rwhp and a good mid range tq boost but will cost at least $500 plus install (if you're not a DIY'er). You can do a short runner without a dyno tune while a short runner with deletes will require a tune.

A march small diameter fluid damper will free up 8-10hp and small diameter waer pump and alternator pulleys will free up 2-3, together these parts will run ya about $175.

 

[97cobratiny]

Thanks again for all the info. One more question though, how commen is it to have the mark 8 longblock in a cobra? All in all I was happy with the dyno results, with the mileage on my car and the few hp mods I have.

 

[na svt]

Thanks again for all the info. One more question though, how commen is it to have the mark 8 longblock in a cobra? All in all I was happy with the dyno results, with the mileage on my car and the few hp mods I have.

It's very common to find mark 8 long blocks in cobras since it's a much cheaper option than a replacement cobra engine. Your engine may not be from a mark 8 but if it isn't there's something causing it to make peak power so low in the powerband.

 

[luke87gt]

I'm not disputing whether this is or isn't a mark8 longblock, but just for reference, my bone stock 96 Cobra made peak power around 5950rpm. Obviously I expect that to jump a few hundred RPM with the free flowing exhaust, short runner, & IMRC deletes. It looks like your dyno graph shows peak power at around 5900, so it's not that far off, but I would expect it to be a hair higher especially thru the off-road exhaust.

Ignore the red line and focus on the blue line (since on your second run it looks like several degrees of timing were pulled just before the car was to make peak power - possibly because the car was hotter on the 2nd run). Your tuner should be data-logging all these items so you aren't guessing as to what is going on!

The timing jumping around is also skewing where the peak power is really occurring. On the 2nd run peak power was made at 5500RPM because your spark advance was not held by the PCM into the 5900-6100 RPM region where peak really *should* have occurred.

 

[97cobratiny]

It's very common to find mark 8 long blocks in cobras since it's a much cheaper option than a replacement cobra engine. Your engine may not be from a mark 8 but if it isn't there's something causing it to make peak power so low in the powerband.

If it is a Mark 8 Longblock does that mean it's not the original motor? Or is that something ford did? Reason I'm asking is a bought the car with 34,000 miles on it from the original owner. I would hope it's unlikely he blew the engine so soon. But who knows?

And I should be getting my taxes soon, so I think I'm gonna go with the March Dampener, Short Runner, and a tune, money permitting. Then a k-member, LT's, and a new mid pipe can come later.