Tuning gurus needed- no top end hp

[evan1170]

Alright, so months ago i installed Crower 264/272 cams and was running an old Fp green turbo and supporting mods. I got my car tuned on a mustang dyno, 290whp 266wtq.Shortly after the car dumped on me and this past summer it was being partially rebuilt (the mod list is what it currently is now on my profile). After the rebuild i got my car tuned, the clutch was gone ntm it was also a hot day and i got 278whp 265wtq. My power loss was excusable because of these factors. I then replaced the clutch and a couple other things and went back... for another tune. 253whp 264wtq..the tuner said the car was knocking at the top end so he couldn't add timing or boost, but is not sure why its knocking. I use quality gas and had a new tank before i got there.I called the shop and they think it may be carbon build up in the engine for sitting for a couple months and not been driven hard in a while. Expecting low to mid 300s, and getting more than 50 hp loss? from carbon build up?? I am just not sure whats going on, a few days ago i found on cyl. 4 the spark plug wire was kinda broken so it was only running on 3 1/2 cylinders if I'm right but i have replaced the wire. I was told to drive it for a while and call them back for a possible retune. For now I'm trying to get at the bottom of this, i have labeled each line as which ones that were when my clutch was slipping and the unmarked lines are the current pulls. If you have any questions pleasee just let me know so hopefully we all can find whats going on with this hp loss.

 

[TexasTurbo]

I can tell you right off that people are going to want to see some data logs of the pulls in question. I'd work on getting those posted here first.

 

[91mitsuman]

I didn't see injectors listed in your mods. Are they currently 450's or bigger?

 

[evan1170]

FIC 750cc injectors,pics are now posted!

 

[tron2119]

Dude, No one is going to be able to help without a log. Post one up and we'll take a look.

 

[turboglenn]

IF the engine is healthy (gaskets in top end HG/VC/IM/EM etc..) are all in good shape and there's good compression and the car is supposedly "tuned" with a good timing curve and decent AFR's, there's one thing I've seen more than any other that makes one engine run different thanthe next even if they are exactly the same builds.. and it is................

bcam/crank timing error!!!!!!!

I would almost put money on one of the cams being off or the crank pulley being slighly off from perfectly centered when the cam marks are lined up properly

I've seen a friends car with a 16g hit HARD but was dead above 5k RPM and i've seen other similar cars where they were a little laggy and boggy with a similar setup but had great top end once spooled and going. And to most (I will post examples of "off timing" pics on here that were "ok'd by the masses on here"

The cam marks can be perfect and the crank can be one of the following three... PERFECT CENTER, just lft of center by the width of the groove, and just right of center by the width of groove..the car will run all three ways with no problems but will only run it's best with perfect center

i've also seen people end up with an exhaust or intake cam off a tooth adn the engine still ran with no damage, just didn't run like it should

here's the only pic i have from an old thread i saw once, is shows how "off" it can be and still run, but with bad performance..although there's no belt on in the crank pic, it can end up this far off in either direction while the cam marks are perfect, so i would start there, seen it more times than not, and done itmyself many times in a row before learning how to get them PERFECT, read the VFAQ if unsure, there's on paragraph in there about the exhaust cam slipping and how to adjust for this and that is what i have to do everytime to get them perfect while in the car

 

[evan1170]

engine is healthy and i did a compression test, everything was fine. I did a WOT pull with 21 lbs of boost and my afr gauge was reading 10.7.. i have noticed my car will backfire a little more now, not very loud but definitely a noticeable pop. I am running bpr7es plugs which should be equivalent to the mods i have, but idk about power output. I know too cold of a plug could cause backfire but I'm pretty sure i have the rights plugs in there. Thankyou for the input about the possible timing issue, i while definitely take a look tommarrow at my car, for the cam gears i know il be looking to see if the notches one up, and for the crank what would i be exactly looking for to check? ( I'm kinda blanking)

 

[chinola69]

Dont know a whole lot about tuning, except for AFC, Is this possible?

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[Boostdriven]

Turboglenn might be right, you need to double check your cam timing, if it is right on you might consider degreeing your cams. I've seen similar problem with another car, after degreeing cams it made a lot more power after 5k rpms. Also check your plug gap and set it to .21-.23

 

[snowborder714]

You guys might want to check the last post date...

 

[chinola69]

You guys might want to check the last post date...

I know its an old thread didn't want to start a whole new thread for my question. Just that the numbers in the link I posted seem a bit far fetched, just wanted someone with tunning experience to give me there opinion.

 

[snowborder714]

So you want to know if 350hp is possible using an S-AFC? If so, yes, I don't see why not.

 

[Lou98GSX]

try getting your arf around 11.5 you might have rich knock .

 

[chinola69]

So you want to know if 350hp is possible using an S-AFC? If so, yes, I don't see why not.

No I know thats possible sorry for confusion. The first linke:

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Claiming 424 at 9psi stock engine.

 

[snowborder714]

Link doesn't work.

Either way, sounds a bit fishy.

 

[chinola69]

Link doesn't work.

Either way, sounds a bit fishy.

Yeah I wouldn't bother asking but the numbers are on a Dynojet.

SMG
Stock k20a
6262 Turbo
9psi on pump 93
for more info on the setup

Even the second link they are claiming 352whp
Stock b18 GSR
BC stg2 cams
Sk2 manifold
550cc FIC injc
HyTech rep headers
125shot