lt500r55

I'm confused with all my reading here, to the point if i put 113 heads on a l98 I do not get the 400tq the zz4 has. if I put the zz4 cam in the l98 also does the l98 with it's ltr out tq the zz4.

or do I have to go carb with it's manifold to get the tq. I always thought the ltr was the tq king but i'm looking at the zz4 an thinking that's a sweet running motor for my 89 Iroc.

why does the corvette l98 or does it not pull the tq #'s the zz4 does. I'm at a loss here...if I get the answer the ltr just can't keep up with the carb in this case I'm thinking I'm going carb if I do anything...Dan

Orr89RocZ

iTrader: (20)

Stock tpi on a zz4 longblock should have a higher peak trq number than the carbed version.

Putting 113 heads and zz4 cam into L98 should basically be same deal.

Zz4 should have wider trq curve and make more hp.

TTOP350

iTrader: (8)

As said, you will gain TQ with that motor under a TPI but lose out on the HP with a TPI.

dmccain

iTrader: (2)

In love the looks and the gas mileage of the TPI system but it does have its limitations. A friend of mine swapped over to a carb and performance intake manifold on a stock L98 and went from mid 14s to upper 13 sec 1/4 passes. The car went from running out of air at 4500RPM to pulling strong to 5500 or so. I myself would probably rather have the fuel injection but sometimes its so troublesome its not worth it to fool with. Ive pulled a cross-fire setup and a TPI setup before after many headaches and cursing sessions with it. LOL

Orr89RocZ

iTrader: (20)

If you put bigger tpi base and runners on it it will gain the power back. Or some other intake like miniram, stealth ram and singleplanes efi, etc. those all will gain the power back

lt500r55

Thanks for the replies much appreciated, an I'm rambling it seems so thanks first

that's the way I was thinking it would go also more torque less hp. the people who have Siamesed the ltr base seem to point to a bottle neck at the injectors as yet another hp holding back point. I would think a Siamesed base would be great myself but maybe get the injector area opened up would be good an leave the runner intact. an I was thinking of concentrating there first.

with trying to use the zz4 as a goal, my stock heads need to come off there some day anyway. with a stock tpi an the zz4 cam an heads (low miles heads in good condition an price) as a possible plan.

I have an extra stock tpi base I intended to open up. if I could pickup the zz4 manifold an carb, heads an cam I would be temped to. I buy the idea a street driven car does not need all that hp but I would never give any back because I don't need it. if the guy comes through with the heads I may go this route..

any Idea's on what to do with the extra stock base it needs a lot of work I know.. an really if these heads don't come through others are out there. I'm leaning to less cam than that hot cam I picked up. all this can be wiped out with a dif manifold an it's really temping my car has been stock so far an this is just crazy it seems...Dan

JerseyGeneral

It a shame, not many of us 3rd gen'ers want to stick with numbers matching. Port the matching heads and lower intake to match. You get the flow your looking for, and that nostalgic feeling of an original classic ride. But then again I'm old school! Just saying!!