I have a 350 in my Z-28. It has a TPI with stock runners, edelbrock hi flo intake 24 psi injectors. I figure is making about 320 hp and 380 ft/lbs. No my question is should I soup up this tpi or go with the miniram. I am gonna put in a bigger cam and want the most mid range power. Will I see a big difference using a miniram?

 

The benefits of swapping to a Miniram really depends on your choice of heads and cam. Bolting a Miniram on a bone stock L98 would not be a "cost-effective" modification (small gain for a lot of money) as the stock heads and cam (as is) really can't flow anymore air than with the stock TPI setup.

However, with a set of good flowing heads and a different cam, and the Miniram can do wonders.

This is the dilema I faced when it came to building my engine - you really need to look at your heads, cam and intake as a complete package. Changing them "one at a time" really doesn't give the gains you'd expect until you get all three are done.

As for the Miniram, check out John Millican's article on modifying a LT1 intake to work on an L98.

 

I have a set of trick flow heads on, the cam is fairly small but i'm moving up to a XR276 hyd roller, gonna either have the heads ported or i'll just move to AFR 190. I've got all the high performance parts, I just don't like the TPI cause when I get on a long stretch of road it just dies after 4500.

 

I got a ZZ4 w/ stock TPI and dynoed @ the wheels 257hp 356tq. I don't know how good your heads are but I think right now 320 hp is kinda high. I am also thinking about a MR.

 

well I have twisted wedge heads on. the cam is mild it's only about 210 duration at about 470 lift. But i'm hoping to move up to a XR276 roller. thats why i'm thinking of the miniram so I can make full use of the cam. A stock ZZ4 is 355 hp, how did you dyno yours at 253?

 

That is with a single plane manifold and a carb???? Stock TPI set up would be around 257

 

I did not realize the drop would be that much. It actually kind of sux now. Maybe its' just the torque but it just seems to be more. And i have a smaller cam than in the ZZ4 engine. Thanks for the info.

 

I believe that 355 hp number is flywheel as well...
257*1.2 = about 310 hp at flywheel with TPI, which I would call real good numbers for stock ZZ4 with stock ZZ4 aluminum heads.

 

The ZZ4's #'s are done at the flywheel. My dyno #'s are done at the wheels. I too was very dissapointed. (considering I can beat most 4th gens).

IMO I think that one of the biggest reasons that the TPI kills the HP of the ZZ4 is that the TPI stops at 4500 and the cam stops at 5200. My motor is mismatched by 800 rpm. Its hard to make power that way.

You going in the right direction w/ a bigger cam. I will do the same when I install my MR. Thats another reason I'm getting the MR and not the SR. Easy to install.

 

Just thought I'd add my sig.

Basically a stock ZZ4 w/ full exhaust.

 

Actually 257*1.1764=302hp. That means he lost 53 horsepower to the tpi. But 356*1.1764=418ft/lbs. Gained 13ft/lbs. This engine was designed for a carb, but so many people mismatch it with tpi.

 

Oh and one more thing.. If you're using a cam that has power only up to 5200 rpm I would not go with a miniram. You need a more aggressive cam with a miniram. .those things like high rpms. A super ram would be more suited atm.