2nd_time_ls1

iTrader: (2)

Hello to all! I am building Autocross/ Time Attack 98 240sx with an ls7 Head based engine. I am currently at the point of finding which inlet manifold to put on it; Mast & Jenvey the ones that intrigued me the most.

Im looking for someone with experience pertaining to these manifolds on 600 hp+ engines. Main concern is the power band of the Mast and the restriction of the Jenvey.

If you have a intake you would have me consider, let me know.

Blown06

iTrader: (32)

The mast is a pretty tall unit and very expensive for a cast manifold. For the power you are trying to make and the fact that this is an autocross/time attach car......I'd probably stick to the stock manifold.

The mast isn't really designed for what you are trying to do in my opinion.

I have no idea what a jenvey is.

2nd_time_ls1

iTrader: (2)

I am going off of this dyno chart from hot rod magazines intake comparison. Fromlowest to highest numbers it follows: ported oem plastic ls7, sheet metal Wilson, mast 4500 Efi. The mast picked up everywhere and an extra 50hp at top.


Jenvey make individual throttle body intake manifolds, like harrop and kinzler: great throttle response and the ability to handle big cams with a calm idle.

Thank you for your outlook!

2nd_time_ls1

iTrader: (2)

I have no problem with intake height. I can fab up some ducting so I can keep the maf senso

The body of this car is going to heavily modified in due time, so this current hood will be scrap either way.

1964SS

iTrader: (1)

The Mast is incredibly expensive. I don't know why they feel it's worth that kind of money. Hell it looks like an edelbrock or holley with injector bosses.

Blown06

iTrader: (32)

Then you've never actually seen one.

1964SS

iTrader: (1)

No I have not in person just online, but a cast high rise single plane intake isn't exactly different from any other. Certainly not enough to validate 6X the cost.

Edit: I see they do have a lot of work done on the inside. That would take up quite a bit of time.

2nd_time_ls1

iTrader: (2)

Please be constructive. If you do not understand the engineering that goes behind testing how air flows through an intake manifold... and developing... and fine tuning. Then you cannot understand why its worth the money.

2nd_time_ls1

iTrader: (2)

Look at the graph. This intake outflows a Wilson g.e. $2500+

gnx7

iTrader: (28)

I have WCCH ported AllPro LS7 heads (429cfm) and the 2 piece AllPro single plane intake CnC'd for each other. In spring it'll be together on a 441ci setup.

I'm in a similar spot as you are 2ndtimeLS1. I plan to run it.... then wait until the FAST short runners come out in spring (If they ever do) or the Vararam dual plenum style that has had equally long delays for release date and test these.... I will be doing 65% street or less.... road race focused 30%+... and a couple drag strip passes a year for fun.

The AllPro intake above 5000rpm to 7500rpm+ rocks... but below that there isn't much information publicly out there. My intake was on a 4.185" bore/3.27" stroke setup and rev'd to 9500rpm which made 625rwhp (360ci/6.0 liters). I'm hoping with 80 more cubic inches to make 700rwhp easily. We'll see as my 1 7/8" long tube headers are not equal length... or stepped... and have 3" collectors due to chassis constraints. It's all in the combo. What goes in... must come out efficiently also.

This is the AllPro... it's massive and will be sticking out my hood like the Hoonicorn. I'm going to run a 4500 series TB.
If you think the intake is expensive... clench tight when you find out how much the fuel rails are!

2nd_time_ls1

iTrader: (2)

Gnx7... Your build is quite similar to mine. My engine will have a 4.155 bore and a 3.622 crank through. Put most my tech into some custom Wisecos for optimal mixture and combustion. As well as 2 Aem 4 channel wide-band controllers to fine tune as much as possible.

I have received one reply from Russ at Mast and that took 2 weeks. Waiting to hear back what he has to say about the dyno charts on the intake. Should be 10 days from now...

What fuel are you running and are you looking for 700 at the crank or ground? Both of those are pretty realistic with the right cam and valvetrain.

Your car is gorgeous and you made the right choice on that there engine! (;

Bill71

I was where you are 2 years ago. I wanted to run the Mast intake but couldn't find much info. I called them and he said the intake was primarily for drag racing and high rpm. Also the 4500 was worth 25 hp over the 4150. The only dyno test I saw is posted in this thread. I did order the manifold from Pace Performance because it was cheaper than directly from Mast. It comes with fuel rails too. I also am using an Accufab 4500 tb. I have nothing to compare it to but my LS7 with heads and stage 4 cam does not seem to be lacking any torque anywhere up to my 7000 shift point. The only tricky thing is the tb has big throttles and even slight pedal movement means a lot of rpm change. I need to slow down the throttle movement.

As for height, I needed a 3.5" tall hood on my 71 Camaro. I wish I didn't need that much since it obstructs the view a bit.

Jimbo1367

Bill71,
Would you mind sending me a PM with bigger pics of your car? Any build thread? I don't want to muck up this thread.

thanks,
Jim

gnx7

iTrader: (28)

I plan to run e85 and goal is 700rwhp. Being that my car is so light.... the power/tq hit below 4500rpm is probably a good thing for traction with the single plane.... even though I have 335/30/18's out back. I want to normally around 7000rpm or below and then when I'm coming up to a corner not have to upshift and then just run it out to 8000rpm if needed. I will be running an LS7 crank and Ti rods with Autotech/Racetech road race pistons.

Motor came with full Jesel solid roller parts and .937" race linkbar lifters. I will get the Cammotion LLSR and my PAC1208x valvesprings are for .750" and less lift which are also still reasonably priced. Most likely under .720" or they just wear out too fast.

Like everyone else... the main concern about this intake is the visibility and stealth factor is gone. When you see it on person.... it's ridiculously tall.... and then add a TB on top!

2nd_time_ls1

iTrader: (2)

Bill71... Your car is gorgeous man!

Thank you for the feedback. You are making my choice on the 4500 very easy sir. I am actually trying to reduce the torque from this motor with a shorter throw crank. Don't want to completely blow the tires off coming out of a corner.

As for that hood clearance... its not a issue for me. being 6'2" in this tall windowed 240 will assure great visibility.

How much street time does that Beauty see?

2nd_time_ls1

iTrader: (2)

Gnx7... More solid of a build that I. The factory rockers will have to do me good for quite a while.

Looks like a 800 hp motor to me... and i thought the 3.622 crank might be too much torque!

I am not a very stealth guy. This is a cross country race car and i aspect it to look the part. lol

I believe i will be joining the Mast 4500 club shortly after i finish school. Nothing says "AMERICA" like a sky scraping single plane on a v8!

2nd_time_ls1

iTrader: (2)

The article on the intake is not from Hot Rod magazine. For all who are interested... http://www.superchevy.com/how-to/eng...erent-intakes/

Bill71

It gets driven every week and I attribute that to the Holley EFI. I have never tinkered with EFI before but there is a lot of online support from Holley and I finally have a good feel for the software.