I've got a beater 5.3 Malibu swap car that I'm putting a MP112 on (truck style) the car is currently an 03 DBW setup w/75mm TB 8 pin. I have a 90mm J-tube and gold blade 90mm throttle body, but it's my understanding this cannot be tuned to achieve wide open throttle without the $250 X-link. Is there much to be gained switching to the 90mm? I have seached for 3 hours this morning and haven't found back to back dyno tests on the switch.

This is a sloppy mechanics style build, I know the limitations of the Maggie but I already had it and I'm curious. We've been spraying a 275 wet shot on the 5.3 for a while now with good success. Only mods are late Z06 cam/springs/moly pushrods. Planning on spraying at least 175 on top of the Maggie and maybe Meth too. This is a see how quick the car can be before it blows project.

 

It will help, how much boost do you plan to push with that 175 shot? Stock TB is 78mm

 

I'll spin the blower fast enough to make max power then start adding nitrous. If it breaks ill put another $200 5.3 in and not as much nitrous

 

I've hit it with 325 a couple of times and 275 at least a dozen.

 

175? Wow on top of the mp112? That is a grip of spray with boost. I have always heard with boost any shot is basically doubled, but that may only apply to turbos. I can't remember anyone spraying more than 100 on top of a Maggie so that should be interesting. I know the 90mm swap is expensive, but with the extra air flow its important.

 

I would guess going to the 90mm would lower boost 1-1.5lbs but still make the same power. Then you up boost to the same level and that's were the gains will be. Ive done this on several different applications and gained quite a bit. Id guess around 20-25whp at same boost level. Also as far as nitrous goes Id say start a lil lower than a 175 shot LOL. No need for meth unless you want it for the extra fuel but the nitrous will lower temps and add a ton of power. Id say start at a 100 shot and it would gain roughly 150whp and 200ftlbs over the blower itself. Then move up to a 150 shot and go real fast. Easy way to 800whp I guess LOL. Keep us posted. Seems like a very cool setup.

 

The Crusty Nova from drag week is my street car. 1100hp stock block/crank 370. Runs 8.50's, my buddies and I know what we're doing but never tried macmxing out a Maggie. My son started racing this car and we're trying see how fast we can go with cheap junk

 

It will gain boost not lower it. Positive displacement blower gain boost with a larger TB if they are moving enough air.

 

Cool build , I like the way you think

Get a powerbond OD balancer and a 2.6 pulley and let her rip , that Maggie will make some power and should be a fun street car . Some dayco 100mm idlers will help but you will have some belt slip up top with 6rib, but it will still be fun.

Adding meth will help also as you prob know , or run her on E85 if ya can .

I would def run the larger throttle body if ya can and at least a 4" intake.

 

I run my turbo car on corn, have to play with tune a lot. I have Holley on it so its convenient and easy to adjust. This will be a tune it on 91 then play with nitrous jets and nitrous fuel pressure to make her eat.