General Evo 3 and Kelfords on stock ECU

[hubz91talontsi]

Well i just put my kelfords in today and the car runs awesome up to 6000... Feels like its hitting fuel cut at 6000, feels like its spitting flames out of the exhaust, just wondering if this is just to much for the stock tune..?

The timing looks fine to me and it idle and runs fine up to 6000.

Evo 3 is running around 9-10 pounds, they are Kelford 272s. Stock Maf.

Just curious, I have a chipped Eprom going in tomorrow with a 2g maf and 865 injectors and turning the boost up as high as i can go on pump.

 

[toofast82]

Have you logged any runs or anything to see your timing curve and if you're getting any knock?

 

[hubz91talontsi]

Nope, i really shouldnt have to log it. Im just wondering if its just to much airflow for the junk ass 1g maf. I wish i could go into more detail of the block and head but i cant :-\.

Ill just double check my timing in the morning and put this chipped eprom in.

 

[toofast82]

Your 272 cams are going to change the VE of the engine, which is crucial especially with the 1gs very aggressive timing curve for pump gas and very rich a/f settings.
You really should have a wideband, logger and a means to adjust timing and fuel to get the setup dialed in

 

[hubz91talontsi]

Well i put the chip in and it still does it, Its back firing right at 5500 with no knock.

sounds like a timing issue to me.

 

[90gsx_luis]

what u need is a tuning tool to see thats really going on

 

[dsmdeliveryboy]

Its the cams mixed with you maxing out the stock MAS, I'm having the same problem.. I would also check for boost leaks etc. But your symptoms sound almost exactly like mine.. Cams, stock mas, low boost hitting fuel cut around the same time etc.

 

[donniekak]

If you are running the kelfords with stock springs, you may have valve float.

 

[hubz91talontsi]

I am running 865 injectors and a 2g maf now, hey guys pay attention.

I dont see anyway im getting valve float.

 

[donniekak]

I am running 865 injectors and a 2g maf now, hey guys pay attention.

I dont see anyway im getting valve float.

20 year old stock valvesprings, and cams with an aggressive ramp rate like the kelfords are a recipe for valve float. What was the spring pressure at what installed height, and what is the spring pressure at max lift? Unless you can verify that these numbers are in line with what kelford recommends, you can't be sure.

 

[hubz91talontsi]

I just dont see how they are floating at such a low rpm.

 

[skatershawn]

i say its timing up top mixed with the aggresive cams!

Get a loggin/tunning system to run to its fullest!
IMO

i believe running a chipped ECU is only good for adding more fuel!!
And you have no way to check or change anything that your ecu is doing!
Id be careful!!!!!!

 

[dsmdeliveryboy]

I just dont see how they are floating at such a low rpm.

So this is all still happening even after installing the injectors and 2g MAS?

 

[RvlutionMtrsprt]

Are you bouncing off the NLTS rev limiter because the clutch wire isn't hooked up properly?

 

[dsmdeliveryboy]

Are you bouncing off the NLTS rev limiter because the clutch wire isn't hooked up properly?

I doubt that is the case, I have mine completely disconnected so I'm sure his isn't that either..

 

[hubz91talontsi]

i say its timing up top mixed with the aggresive cams!

Get a loggin/tunning system to run to its fullest!
IMO

i believe running a chipped ECU is only good for adding more fuel!!
And you have no way to check or change anything that your ecu is doing!
Id be careful!!!!!!

Yeah this just temperary until i get a aem and 2250 injectors

Are you bouncing off the NLTS rev limiter because the clutch wire isn't hooked up properly?

Nope, factory ecu doesnt have NLTS and i didnt get it on my chip.

 

[Yngvar]

If you are running the kelfords with stock springs, you may have valve float.

thats what I'm thinking

 

[90tsiPA]

I'm going to say the valves are floating.
This guy had crower valve springs with titanium retainers and valve floated at 4000 rpm
http://www.dsmtuners.com/forums/cylinder-head-short-block/377673-my-crower-valvesprings-failed.html

 

[hubz91talontsi]

I ran comp 264/272 on stock springs without issue.

 

[donniekak]

I ran comp 264/272 on stock springs without issue.

Search for info about advertised vs effective duration, and ramp rate. The kelford 272's have an effective duration similar to 280/288 cams, with a very agressive ramp rate. Meaning the valve opens, and (hopefully) closes much faster than other 272's. What this does is "throw" the valve out of contact when the springs don't have enough force to overcome the inertia of the valve/spring/retainer.

 

[hubz91talontsi]

Im starting to think youre correct but i still think the timing may be off a little, i almost want to try to take it to 7k to see if a valve breaks .

 

[daren_p]

I ran comp 264/272 on stock springs without issue.

Comp 264/272 & Kelford 272's are no wears close in comparison. Even the Kelford 264/260 are more aggressive then most other "272" cams on the market.

I just dont see how they are floating at such a low rpm.

Valve float isn't just because of rpms, it also has to do with cam profile (& can happen at much lower rpms then near redline). Kelfords do have an aggressive profile & should not be used with stock springs.

 

[hubz91talontsi]

Alright guys thanks for the info, looks like i can finally get a Curt Brown head .

Hrmm well since im still not 100 percent convinced on my way home i decided to get on it again, went up to 6200 in first (doing the ### back firing thing) and all the way up to 7200 (without back firing) out of gear.

So tomorrow morning i will re do the timing and have another go at it.

Seems that when i advance the timing it raises where it is back firing.

 

[williillii]

How is your ignition system? Maybe you're not getting a clean spark and its misfiring like crazy. That was my first thought.

also

Nope, i really shouldnt have to log it.

Thats a really naive thing to say. First thing you should do when you have a problem you cant figure out is log the car..

 

[hubz91talontsi]

Well i had a bit of a timing issue and it is def valve float .

They start to float right around 4400.

kiggly springs here i come