MMR Shortblock=Lost power???

[SVTwnaRUN]

Ok,guys I have been having a issue and its going throu my head
these past day's that why would I loose hp after a build short block
and upgrades? I mean would it gain anything The last time I talked to Mark
at (MMR) he was telling me that I would gain some power overall I lost quite a bit. About 40hp lost, I really think something is going on something is not right here after 4k spend and actcualy loose hp insted off gain its really feels that it wasnt worth the build,I remember that I talked to Mark about My plans and build what he suggested I followed it and I wanted to share it to see what are your thoughs,what you think is wrong.

Here are my mods before and after:

stock Eaton
2.76 pulley
BBK OR X
Borla Cat back
Mafia
JLT RAI
60#s
BAP

Dyno: 479rwhp 490Tq @14spi 11.4 A/F 19*timing

Stroked 4.75 1000hp SE Block
8.5.1 Compression
Stock Cams
MMR windage
MMR billet gears
Pistons Notched
Pistons Coated
Mild Ported heads
2.76
Stock Eaton
LFP SB
SB Plenum
BBK OR X
Magnaflow Cat back
80#s
BAP
MAfia
JLT RAI

Dyno: 440rwhp 525Tq @14psi Then Drops to 10psi at 5800rpm 11.3 A/F 19*timing


If anyone can Help with this Bc I cant stop having a heache about why or how is this posible???:fm:

 

[03cobraracer]

well maybe with the stroke and the mildly ported heads now the eaton isnt pushing enough air through the motor and you need to spin it harder? specially since you said its dropping psi higher in the rpms... it probably needs more air pushed through it now.. i could be wrong though. thats the only thing i can think of. plus new motors are tight and need to loosen up a little with mileage... only 2 things i can think of.

 

[itSSlow98]

If the boost is dropping up top then your getting belt slip. There is no reason you should drop 4psi up top. Your missing out on the area your gonna make your peak HP.

 

['88347coupe]

No you are losing boost in the upper rpm range because at that rpm, the engine is becoming more efficient than the blower can keep up with. That actually a good thing. Did you tune it on the same dyno? Does the car feel like it lost power? I wouldnt worry to much about dyno numbers anyway, you need before and after track numbers to verify that you lost, or gained anything.

 

[selbyvince]

well maybe with the stroke and the mildly ported heads now the eaton isnt pushing enough air through the motor and you need to spin it harder? specially since you said its dropping psi higher in the rpms... it probably needs more air pushed through it now.. i could be wrong though. thats the only thing i can think of. plus new motors are tight and need to loosen up a little with mileage... only 2 things i can think of.

im with this guy

 

[SVTwnaRUN]

well maybe with the stroke and the mildly ported heads now the eaton isnt pushing enough air through the motor and you need to spin it harder? specially since you said its dropping psi higher in the rpms... it probably needs more air pushed through it now.. i could be wrong though. thats the only thing i can think of. plus new motors are tight and need to loosen up a little with mileage... only 2 things i can think of.

sOmething like that mention My tuner but I still think its a bit loost of power

If the boost is dropping up top then your getting belt slip. There is no reason you should drop 4psi up top. Your missing out on the area your gonna make your peak HP.

I checked for belt slip and theirs isnt any belt its nice and tight

No you are losing boost in the upper rpm range because at that rpm, the engine is becoming more efficient than the blower can keep up with. That actually a good thing. Did you tune it on the same dyno? Does the car feel like it lost power? I wouldnt worry to much about dyno numbers anyway, you need before and after track numbers to verify that you lost, or gained anything.

Yes I tuned it at the same dyno with same tuner the car doesnt feel slow its just that I think it would of done better numbers with the extra parts for more pony's? the only thing I started to notice is the blower is making a lil buzyng sound and I dont know if something its going bad or its suppost to do that.

 

[71catruck]

With your boost dropping off as much as it is there might be somthing going on with that not sure. But from your before and after numbers you gained 35tq that's a good amount. I agree that you need more air. You strocked the motor and ported the heads I'm surprised you even seeing the same 14 psi down low. Like said befor track times will tell or go race some one that was a close race befor and see what happens.

 

[SVTwnaRUN]

Will a port on the eaton help on anything? I'm assuming it will pick something up better then what it is. I will have it tested track wise.

 

[bambinov8]

You losing power because of the boost drop. I dropped 2psi on my car due to belt slip on top and couldn't even hear it and belt felt tight. How old is that belt? Food for thought, I made 755whp @24psi, with belt slip on top I lost 2psi and made 722whp. You down 4psi, that's your lost HP man. Boost leak isn't the case because your air fuel will be off. Get a new gates belt and make sure you datalogg boost

 

[MysticRob]

You haven't changed all that much besides having a bit more displacement AND you're still breathing through the stock NON-PORTED blower. That's holding you back. Your new parts will support more power, but they don't make it because of that initial restriction. Port the Eaton or put a twin screw on it. Cheers!

 

[03Cobranator]

I agree with everyone else but if your worried about the motor just do a compression test and leak down test for your own peace of mind. If it comes out good then you surely have no worries!

 

[98 Saleen Cobra]

Pretty much what everyone else has said.. Go and race another upper only eaton and see how it does.. Like we've said in the other thread, numbers are just numbers.. The car feels strong it is.. The blower is to small for you setup, you need something bigger.

 

[younggun04]

I checked for belt slip and theirs isnt any belt its nice and tight

I am with Bambino. Just because your belt "seems" tight it might not be. On my whipple I had a belt that felt tight and I couldn't hear it slipping. But it was slipping and was down 30 HP. new belt and all was great. Gain my power back and then some.

 

[98 Saleen Cobra]

I am with Bambino. Just because your belt "seems" tight it might not be. On my whipple I had a belt that felt tight and I couldn't hear it slipping. But it was slipping and was down 30 HP. new belt and all was great. Gain my power back and then some.

Then you went turbo, and punted everyone ahahaha

 

[03cobra#694]

Might want to check the boost bypass also.

 

[jrichber]

Why post pretty much the same thing and hope for different answers?

http://www.svtperformance.com/forums/terminator-talk-229/921444-new-dyno-numbers-not-happy.html

What you got from last post is blower is holding you back no? I would also goto question do you have a snub idler? With a 2.76 would hard to believe no belt slip without it.

 

[Boss 327]

Why post pretty much the same thing and hope for different answers?

http://www.svtperformance.com/forums/terminator-talk-229/921444-new-dyno-numbers-not-happy.html

What you got from last post is blower is holding you back no? I would also goto question do you have a snub idler? With a 2.76 would hard to believe no belt slip without it.

Maybe he's trying to throw more mud on MMR :shrug:

 

[MysticRob]

Yeah, OP, you made 2 threads on the same subject with the same answers given in both. AED is famous for getting the most power possible out of these cars, so seriously doubt your problem lies there, and we don't even know whether your differing #s were on the same dyno, or due to atmospherics. Though MMR does sometimes get a bad rep on here and elsewhere, you have nothing diagnosed to make anyone believe the issue lies there either. Your unported blower is the most likely cause of the HP loss and TQ gains -- resolve that and update with new #s.

 

[SVTwnaRUN]

Nothing to bash on MMR they been really great with their service never have had
A problem with them, and I did this other post bc of I was thinking about this at 2am
An though really 4k in just short block and 3k in parts and results be lower hp then before??? I do Understan about blower to small and thats the issue holding back,
I did ask my tuner did he see any belt slip in his data log but he said no?
So I'm just wanted all this to hear ur Ideas and so far its going for my blower.

 

[Boss 327]

Did you ask shaun about it?