Engine knock stealing my HP!

[2014Paxton5.0]

Around 6300 rpms my engine drops timing on the dyno and instead of getting my peak hp, the graph just drops. I have just got a full tank of 93 oct at BP this morning and put in a lucas octane booster. I also had a oil separator installed from bobautosports. I have a paxton 2200, torque booster 3.3 wastegated. DW 1000cc injectors, vortech bap, bbk long tubes, bbk high flow catted xpipe, pypes catback. Lund tuned. The shop I'm at recomended removing the cats, as the oil separator and new gas with oct booster didnt seem to help so they are doing that as we speak. Has anyone ran into this issue? What recomendations do you have?

 

[SID297]

Why is it pulling timing? If it is the knock sensors, then what is the source of knock? Have a datalog?

 

[2014Paxton5.0]

Why is it pulling timing? If it is the knock sensors, then what is the source of knock? Have a datalog?

Well the shop thought at first it was bad fuel, then maybe blow by. Which is why i did the steps noted. But now they think it might be the cats. The are cutting the cats out now

 

[SID297]

I highly doubt it's the cats (if they are factory).

 

[WIST2013GT]

Did you check for exhaust clearance? Maybe you have some pipes banging somewhere.

 

[2014Paxton5.0]

It's bbk xpipe high flow cats, yeah but it did make a real crappy smell when they did a dyno run. I'm wondering if they are clogged or messed up somhow. I also feel like it could possibly be the tune but idk lund ussually nails it.

 

[2014Paxton5.0]

Did you check for exhaust clearance? Maybe you have some pipes banging somewhere.

I'm pretty sure they checked that out while it was on the dyno but I'll double check

 

[basspro302]

Are they looking at knock + or -? Or total spark. It is possible they are confusing the knock sensors adding timing not pulling it. If the knock sensors are at 0 or reading negative you are good if its + you have knock it isn't uncommon to see a little + knock once in a while

 

[2014Paxton5.0]

Are they looking at knock + or -? Or total spark. It is possible they are confusing the knock sensors adding timing not pulling it. If the knock sensors are at 0 or reading negative you are good if its + you have knock it isn't uncommon to see a little + knock once in a while

Would they both cause the drop in hp at 6300 rpms. It should be pulling up all the way till 7000 at least

 

[2014Paxton5.0]

I had to boost the engine out to get the headers on, so I'm having them check the engine mounts, maybe i didnt tighten them down properly. They said they checked all the exhaust previously

 

[2014Paxton5.0]

Update** they fixed the knock, but the tune needs to be updated because the timing was set low because of previous knock. You were on to something with the + - ,

 

[2014Paxton5.0]

Its 0 now so they just need to add timing

 

[basspro302]

So what happened?

 

[SID297]

What shop is doing the tuning?

 

[2014Paxton5.0]

Lund tuned it. Turns out the tune is fine. I just have to do some wot pulls through the rpm band up to at least 7000 to get the chip to realize that it can put timing back in because there is no knock anymore.

 

[WIST2013GT]

Any updates? Are you still on the dyno?

 

[2014Paxton5.0]

Any updates? Are you still on the dyno?

By the time they fixed the knock and got a reply from lund they were going on lunch and I wasn't going to wait the rest of the day, So I'm coming back to finish dynoing later. I have to do WOT pulls to get the chip to realize there is no knock anymore so it can add more top end timing back. they did one more run before that and it picked up 8 rwhp, so the dyno read 552 SAE. I anticipate picking up another 10-16 rwhp after I have done my WOT pulls to 7000+ rpms in order to get the added timing back. I got like 3 different graphs, I'll probably post here soon.

 

[2014Paxton5.0]

Btw they cut out the cats and that fixed the issue, I also had a bobsautosports oil separator and added a a lucas octane booster which is supposed to add like 4 octane to a 15 gal tank. even with those i still had the knock. Seems that the cats were the biggest issue.

 

[WIST2013GT]

How much timing is in the tune now? What type of dyno are you on?

 

[2014Paxton5.0]

How much timing is in the tune now? What type of dyno are you on?

Well, when I emailed lund a while back before the torque booster, they said it was max 16 degrees. Well, I just looked a data log file when they were tuning my car with just the paxton and base pulley and the max I saw was 15 degrees. So I'm a bit confused on that. I am emailing them again to find out. I'll see if i can upload the excel file that shows the data log. Either way I'd like to be at at least 17 degrees max timing so I can get the numbers I'm shooting for. the tune never changed when i put the torque booster and 3.3 pulley on. They said I could just use the same tune. Dyno jet dyno