Wilka

iTrader: (1)

I know there are countless threads on intake manifolds so before you try to refer me to the search feature, I cant find what I'm looking for. Here is my situation:
86x89 sleeved motor
12.5-12.8:1 ish motor
Fully built block and head minus rockers
Pro2s
Stock port itr head with a 5 angle VJ.
Edelbrock victor x with port matched 74mm sk2 pro throttle body.
Currently going to 9k.
Tuned on pump e70

I've hit a snag in the hunt for more out of what I have and figured I'd try to get some feedback from the community.
Made 244 and 165 on drag radials on a dynojet.
Huge power dip around 5 and motor gets a huge kick in the *** around 6500-7200
Looking to try and smoothen out my graph and net some better track times.
My options are:
A. Send my manifold off to be ported and rev to 9500 and see if I make any gains.
B. Go ported ultra street (4piston cnc) with a plenum spacer
C. Ditch it and go to an ultra race and ktuned 80mm

Car still sees the street once or twice a week when traveling to "mexico" for weekend outings on occasion.
Maybe someone had this problem before and had some solid feedback with some evidence.
I see tons of all motor b's with both manifolds and get mixed answers from everyone.
According to what I've read, plenum is supposed to be between 1.25 to 1.5 bigger than the motor, if that's the case, the street is out of the question, but due to design, it sort of doesn't follow, its designed to have more even airflow distribution compared to other manifolds on the market and the ultra race being the same design just being in reverse with plenum and runners.
Trying to make the most of what I have without over buying for something I don't need.

Feedback is appreciated.

2LEM1

iTrader: (1)

I think you'd see much larger gains by porting the head, I don't think the Victor is holding you back.

What RPMs does torque fall off?

What header are you using?

Are you running exhaust?

Wilka

iTrader: (1)

Hoodexit and I only see my graph in mph, not rpm. Looks to be about 3/4s or so of the way up where it peaks and then flattens out.

Wilka

iTrader: (1)

I had another theory where going with the ported ultra street may band aid the fact of being a stock port head and help promote the velocity I may be lacking.

TheShodan

iTrader: (14)

mmmm.. Nah. There's nothing like having the head be able to breathe better than relying on some plenum to do the job for you. That means porting and a good cam to finely tune valve timing events to get maximum airflow.

As nice as an Ultra Street manifold, It's still just an intake manifold. I think you're starting to self-rationalize justification for buying one.. If so, go ahead, but remember, you made that decision, so don't expect the world to change overnight with it.

2LEM1

iTrader: (1)

Power is made in the head.

With the build you currently have, nothing will free up power as much as a good head port at this point.

Yes, you can probably pick up a few ponies with another IM, but you'd be far better off getting the head to flow more IMO.

k20z1ej1

You have all the ingredients to make 260+... except a ported head. The fuel, cams, displacement and intake manifold are all there. The stock ports are the only thing holding you back, as others have already stated.

Mach1n1st

I used our CNC ported ultra street and it worked very well. 245/160 whp/tq on mustang dyno.
84x89, 11.5:1, pump e85, blox tuner 3 cams,CNC ported head, rmf big tube header, 3" exhaust.

Wilka

iTrader: (1)

See, I'm wondering if the added velocity helped torque is comparable but as you stated, on a mustang dyno, also had a ported head.

PSI GUY

iTrader: (2)

Send the head to 4Piston and be done with it. That VictorX is really all you need unless you are trying to make power past 9000 rpms. You will see more gains in the head than anywhere else. I played the intake manifold game, it's expensive and until you get into a big camshaft you will not see small or even noticeable gains.

Wilka

iTrader: (1)

What kind of times can I expect? Itr trans on 23's weighing about 1950-2150?

PSI GUY

iTrader: (2)

Too many variables, anywhere from high 11s to low 13s.

GSR_ITR_BOIB

Go with 4Piston's ported Ultra Street manifold. Might as well have them port your head to match too. They do great work. Take the word of somebody who's had the exact items that I'm telling you to get lol. Could also think about going with Pro 3s.

Wilka

iTrader: (1)

What gains did you make, did you use a spacer? What manifold did you have before?

Wilka

iTrader: (1)

Bump interested in everyone's experience.

GSRcivicSon

forget the intake manifold and port the head. that is ABSOLUTELY where you are lacking. sure an intake manifold may net you a bit of power, but it also may not. the victor x is good enough for your setup. a stock port head is not though.

vtecmaster85

velocity may not be that big of an issue with the 86mm bore and pro 2 cams. could also try bigger cams too. but send it to a reputable porter and tell them you dont wanna lose much velocity.

warpig1

port the head