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View Full Version : Surging......


Exposed
07-03-2007, 07:56 AM
Hey Guys, I did a bunch of mods to my 03 Cobra last week. I also had it tuned last week on a dyno and bought the Xcal2. The car runs great now... The problem is now at low speed (1000-1900 RPM), it has a slight noticeable surge. Like at 1100 RPM's, 5th gear just going about 30 MPH, it is real noticable. Cruising on the Interstate at say 2000 at 70 MPH, it is not there or not noticeable. I did not have or never noticed it prior to the mods. I also don't have any engine lights on the dash to indicate something is not working properly. Is this related to the tune or maybe something else?????

blk04cobra1
07-03-2007, 09:05 AM
Sounds to me like the drivability in the tune needs to be tweaked...

ORANGE CRUSH
07-03-2007, 10:46 AM
Did you change the TB and Plenum?


I had the same thing happen to me and the issue was with the TB.

Exposed
07-03-2007, 10:58 AM
Same TB but changed to JLT cold air induction..... Did you adjust the TB or have to replace it?????

blueblazes
07-03-2007, 11:26 AM
Sounds to me like the drivability in the tune needs to be tweaked...torrey hit this one on the head. To many tuners these days are trying to tune 10 cars a day and are just tuning the wot fuel trims and arent paying any attention to the short term fuel trims and drivability factors that need to be tuned. Instead of taking all the time to do that they just rely on the cars adaptive learning to take care of those issues and people like you end up getting the short end of the stick because the tuner dont wanna spend the time to do it right.

Torrey is great guy and knowledgeable if got questions pm him and wrack his brain they are good people

Exposed
07-03-2007, 12:11 PM
Could be.. The tune was done by Triangle Speed Shop and their reputation is pretty well known around the Houston area for being about the best in tuning. I talked to them yesterday and they were more than happy to look into it for me.. The only problem is they are a 260 mile (round) trip from my house here in Katy. I am sure they can solve the problem if it is tuning parameters and I go back to their shop. I was just trying to verify that is what is needed before a trip back over there. If there was something else (like a TB problem) that might need addressing that I could do, would save me the expense and time... It stands to reason since it was not surging before, it would be caused by the tuning or something tied to the tuning....

valightning
07-03-2007, 12:25 PM
Try plugging the EGR vacuum line. Disconnect the vacuum line from the EGR valve and plug it with a screw, etc. If the EGR is the problem it will correct the surging immediately.

Exposed
07-03-2007, 12:36 PM
Will give it a try this evening when I get home...
thanks

blk04cobra1
07-03-2007, 05:31 PM
TSS does seem to have a good reputation across the boards and did/does have the quickest procharger car in the country...I think what may have happened is what Blueblazes pointed out...some times a tuner will concentrate on WOT trims and maybe forget to check the drivability...this can be difficult to get perfect if the dyno is not a load bearing dyno...sounds like TSS is going to help you out though, keep us up to date :thumbsup:

SuperG
07-03-2007, 05:51 PM
Could be.. The tune was done by Triangle Speed Shop and their reputation is pretty well known around the Houston area for being about the best in tuning...
Ahh...this sounds like Calvin! Yeah, I have a similar problem, but have not called to ask them about it...perhaps I need slight change to my tune as well.

puzzle13
07-03-2007, 06:22 PM
What kind of plugs are you running??? I was running Brisk plugs and had the same problem when cruising at low rpms. Changed the plugs to NGK TR6's and the problem went away like magic.

blueblazes
07-04-2007, 03:04 AM
another thing if you wanna verify its tune. first does this surging happen when sitting idle? If it does then flash the tune back to stock and see if it stays. DONT DO THIS IF IT ONLY HAPPENS UNDER LOAD YOU WILL MOST LIKELY GET DETONATION FROM FLASHING BACK TO STOCK WITH PULLEY SWAP AND DOING THIS UNDER LOADED CONDITIONS.

Also check and make sure your iac is clean and clear.
If iac is clogged or dirty it can cause surging issues. Also verify no vaccum leaks anywhere.

Im throwing alot of possible solutions your way hope one turns out to be it.

I dont know what mods you have but if the car is relatively stock and you dont have any mods to change teh boost levels then you could flash it back to stock and see if the problem persists. Please state your mods so can better advise on this before doing so. Hate to tell you to do wrong thing :thumbsup:

Like previous poster stated its good to upgrade to tr6's. Depending on what boost level your running they should be gapped differently will be able to better advise on that once your mods are stated

Exposed
07-04-2007, 06:18 AM
Strangely enough, when we did the tune, I still had the factory plugs installed. We we getting blow out at higher RPM's. So we put a fresh set of plugs in.. They are the Brisk GR14S... According to Puzzle13, he had the same problem.. Since TSS did the work on Gary's Cobra, now curious if Gary has the same plugs since he is experiencing the same problem... I may swap them out just to eliminate that from the equation.... Here is the list of mods so Blueblazes can recommend the proper gap for the NGK TR6's.

Magnaflow Catback Exhaust
Magnaflow Tru-X X-Pipe
JLT Performance Cold Air Intake
LFP Intercooler Heat Exchanger
Billetflow Supercharger Pulley 2.76
Billetflow 4 Pulley Idler Kit
IRS Brace
SCT Xcal2 Tuner
Performance Tune at Triangle Speed Shop (Orange, Texas)
Getting about 15 LBS. of boost at WOT

The surge is not that noticeable at idle. It seems to be when the engine is loaded and after warmed up. I leave my house in the morning and drive 30 MPH for the first 3 miles then get on the Interstate. I normally run in 5th gear at 30 MPH (about 1100 PRM's). At this speed coming out (when cold) don't seem to notice it that much. Coming home in the afternoon, car is running normal operating temperature and much more noticeable. If I go into 4th (RPM's come up some), it is even more noticeable. I think I will pickup a set of plugs today and install this evening to see if that is the culprit. I sure hope so, definitely save me gas going back to Orange....
thanks guys for the help..... I do love the way it performs now with the mods....

Exposed
07-04-2007, 07:10 AM
One other thing.. Is the NGK TR6 the actual part number of the plug? I am looking at the NGK site and they show a bunch of plugs for the 03 Cobra. They show Premium, Super Class, and Regular Class. Here is the link to where I am looking..
http://www.ngk.com/results_app.asp?AAIA=1410578

I am assuming the Premium Class Iridium is the best they offer (or seems by the price). They do show a TR55IX. I did a search and they do have the TR6. It shows as the Regular Class (bottom line). It does fit the 4.6 on the application chart but does not show up for the Mustang Cobra.

Also, can you get these plugs local like at AutoZone or O'Reilly's???? They don't show these on their websites... Also Triangle said I should run one step colder than stock.

XCOBRAX
07-04-2007, 07:32 AM
This is what I used http://store.summitracing.com/partdetail.asp?part=NGK%2D4177&view=32&N=700+150+4294907915&appfilter=1#Application

Don't use the Iridium plugs.. they don't work in Terminators. Try the initial gap at 035.

puzzle13
07-04-2007, 11:54 AM
The stock # for the TR6's is 4177. Do not gap them over .35 or you will get blow out problems. I actually have mine gapped at around .33 and you should have a little more boost than mine as I have a 2.8 pulley. At .36 to .37 the blow out problem was worse.

As to the brisk plugs ... they didn't burn all the fuel, not many problems on the street, but road racing stress caused extra heat and loss of timing. Go to the cheap NGK's.

Exposed
07-04-2007, 12:51 PM
I just picked up a set on the way home. Will install here later today after she cools down a bit... Will let everyone know if that took care of the problem...
thanks

Exposed
07-04-2007, 07:03 PM
I installed a set of the TR6's this afternoon. I have been out for a couple short trips after installing. The Brisk plugs I pulled out looks fine. They only had probably 300 miles on them. I will know for sure tomorrow when making my normal trip to and from work on the results. As of right now, I think the new plugs have corrected the surging. The motor seems to run really smooth now and low speed cruising seems to be fine now. I did not notice the surging any while out... I am keeping my fingers crossed that this has solved the problem. It is amazing to me why the high end silver plug does not do as well as the cheap standard ones. I am sure the TR6's won't last as long but for $2.00 a plug, that is cheap....Will keep everyone posted tomorrow on the outcome. I appreciate you guys input.....

blueblazes
07-05-2007, 01:25 AM
nothing beats a good tr6 plug

and yeah .035 is good gap for your boost lvl

Exposed
07-09-2007, 06:12 AM
I hesistated on saying the surging was gone last week. I made a trip to North Louisiana Friday to see my dad. I put about 700 miles on the Cobra. Final outcome, I did not feel the surge one time on the trip. So, in conclusion, I think the plugs were the culprit. I really can not understand why a higher end plug would not perform better than the cheap stock ones.... Anyway, very pleased with the performance and even the mileage. Checked mileage both ways driving 65-80 MPH and got 21-22 MPG.... That is about 3 MPG less than before all the mods and tune. The performance now is considerably better witht the mods so I don't have any reservations about the loss of a couple MPG. The Cobra did great..
Thanks for the help...

ausie
07-09-2007, 11:22 AM
This is what I used http://store.summitracing.com/partdetail.asp?part=NGK%2D4177&view=32&N=700+150+4294907915&appfilter=1#Application

Don't use the Iridium plugs.. they don't work in Terminators. Try the initial gap at 035.
Any suggestions as to why they do not work in Terminators? I was considering them as replacements for the Denso's I had. Considering the cost of the $2.00 plug, sounds like a better deal.