Do I really need a BIG GULP ???
 

Hey team... I am planning the budget for my Phase.2 build (see below in my sig) Planning to max out my stock low end fueling (JMS only) and have heard I should be good to around 750rwhp. With that said... If I port the blower, and a pinch more boost and a cam... do I really need a Big Gulp this round? I assume it would only hold me back if I added a low end kit and wanted to hit 800+ correct?

I'm thinking you might, but just an FYI...I was making 688 rwhp at 45% ethanol and went to 60%, using a jms unit thinking I'd be ok if it went to 700+. Nope, leaned out 2 cylinders and $14k later...

Did it have the lean condition cause of the switch to E and not enough fuel *pressure*?


I've veen debating switching to E but I hear alot of stories of blown engines cause of going to lean.

She was good at several events at 48%. Should be better at 60%, right? Nope. Cool weather and good da and kaboom. 17% lower with the usual stuff and it looks like injectors on those 2 cylinders couldn't keep up. Ugh!

If I remember right I think it's been confirmed that the OE intake is good up to 800 HP. The big gulp is nothing but noise up until that point.

Standard Rotofab is good up to about 750whp, it can't hurt to add a Big Gulp below that point as long as the car is tuned for it, but it may not offer much benefit either until after 750whp.

Porting the blower and adding a 103 tb while having headers with high flow cats, then you want to restrict how much incoming air into the engine makes no sense. The more air you can pass thru the engine unrestricted the better your performance will be, this is mechanics 101.

Yes big gulp is needed.

I ran my original Rotofab to about 770. Hurt the motor and replaced the short block and that that time we went to the big gulp and made 850 plus. So I think you can go to at least 775 or maybe 800 max. Beyond that and according to Mike at Rotofab you really don't need it till your at that level

You're going to be tuning anyways, so why not? You could sell your standard RF and put that toward a new one. You'll have to figure out how to get one here in CA. A lot of people say it's not worth it at that power. Maybe they're right, and you'll only pick up a handful or two Bald Eagles, but if you're going to a 103 - why not get a BG? I hear tuning (idle, I guess) can be a bit of a pain, but we didn't experience that. We did have to tune for it, after switching from the standard, so it seems to me there is something to be had, even for mild mods' like us.

My vote - if it's in your budget - why not? JMHO.

That's pretty much what I did at 700whp. I figured I might as well do it now, in case I decide to do more mods later.

I think at the level you are planning your engine can efficiently handle and use increased airflow. As noted, you will be tuning your engine anyway, so the Big Gulp makes perfect sense.

The Big Gulp isn't worth it until you at least port the supercharger and run a 103mm tb. If you put it on a stock supercharger and throttle body then yea it's not going to do much being there is a restriction upstream. I don't really base stuff off of a arbitrary power number. It has more to do with the setup and combination of parts.

I'm at 855 to the wheels using a JLT intake for a point of reference. The intake tube visually matches the diameter of a Katech 103. So a "regular" intake doesn't seem to be hurting my situation.

Mark