TravRMK Posted June 11, 2007 Share Posted June 11, 2007 Hi all, I have an early 260Z, and will eventually build up an all out turbo L28ET to drop in. For the time being, since the rest of the car needs attention, I will be spending more money there. I will freshen up the L26 with flat top pistons, port match the head, and keep the stock 260 cam, rods, crank etc. The car came with dual Weber DGV's, but may snag some triples. My question is, have any of you actually gained much over the stock manifold with headers? Also would a 3" exhaust kill any low end power? I don't really want to redo the entire exhaust when I go turbo, but will if need be. Keep in mind I will probably drive it this way for a couple of years while I build, and collect all the parts for my all out turbo motor. Quote Link to comment Share on other sites More sharing options...
johnc Posted June 11, 2007 Share Posted June 11, 2007 If you're planning on building an all-out turbo engine you'll need every dime you can scrounge. Spending money modifying an engine other then your turbo engine would seem to me to be a waste of money. But, its your money. A header will give some benefit IF you spend time and money on some internal engine work. The exhaust will give you more bang for the buck then a header. Quote Link to comment Share on other sites More sharing options...
ckelly78z Posted June 12, 2007 Share Posted June 12, 2007 I used my stock exhaust manifold on my 78Z and ported the heck out of the lower end to be able to accomodate the much larger 2.5" downpipe and exhaust sytem that came with the MSA superturbo sytem. I noticed that the top end performance of the motor was MUCH improved, and it revved a little quicker. I wouldn't spend much money on mods that can't be used on your turbo buildup as well. Quote Link to comment Share on other sites More sharing options...
TravRMK Posted June 12, 2007 Author Share Posted June 12, 2007 Thanks for the replies guys. I agree, and don't want to spend too much on this motor, but I will probably have to drive the car with this engine for a couple of years. I just want all the umph, I can extract from the current one so I have something fun to drive in the meantime. Quote Link to comment Share on other sites More sharing options...
TravRMK Posted June 12, 2007 Author Share Posted June 12, 2007 What do you guys think of a 2.25, or 2.5 inch pipe off the manifold, and then step up to 3" about where my downpipe for the turbo engine would end? This way I wouldn't have to redo the entire exhaust with the new engine. It would probably be between 12-18 inches long. Would this be enough to keep a little low end torque with the L26? Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted June 12, 2007 Share Posted June 12, 2007 In my 260Z the 2.5" pipe is more than plenty for the slightly raised comression ratio. I don't think your motor will fair too well with a 3" system as far as torque goes. Quote Link to comment Share on other sites More sharing options...
e_racer1999 Posted June 12, 2007 Share Posted June 12, 2007 this is what i plan on doing: build up a decent NA motor that's not gonna break the bank (ie buy from members and used). when you decide to go turbo, sell your HIPO NA stuff and use the funds to finance your turbo build. especially if you are going to be running an NA combo for a couple years Quote Link to comment Share on other sites More sharing options...
Daeron Posted June 13, 2007 Share Posted June 13, 2007 If what I am reading is correct, he is talking about building an exhaust system of an appropriate size for a moderately modified stock engine, op to the point where a catalytic converter would wind up.. and then, from there on back, upping the pipe size and using a large flow cat and 3" exhaust system so that much of it could be left in place when the nice turbo motor goes in. IMO, as long as you have a good 12-18" stretch of moderately sized exhaust (that long, fully collected) you should be able to achieve the scavenging effect desired from that. After that point, stepping up to a larger exhaust size shouldnt hurt much.. it may have some detrimental effect, not having the full length at the narrower size; but the impact should be minimal. I am no battle-hardened tuner; my knowledge is thus far based primarily on reading and limited work on mine and other peoples cars.. but from what I have learned a short pipe can provide most of the exhaust scavenging. Quote Link to comment Share on other sites More sharing options...
TravRMK Posted June 13, 2007 Author Share Posted June 13, 2007 Yes, that is what I meant. I will probably do this since I don't want to have to make 2 complete exhaust systems. I will not have any smog stuff on, and no cat. But where the cat would be is where I would step up from the smaller size to the 3". Since I will have to make a custom downpipe from the turbo, that should be all I have left to do once the turbo motor goes in. Well, at least as far as the exhaust goes. Quote Link to comment Share on other sites More sharing options...
CarolinaZ Posted June 13, 2007 Share Posted June 13, 2007 Have a 77 that has a manifold that over the years has shrunk or so Im told by two or three exhaust companies..I have a header that a friend gave to me a couple of years ago..all things considered and the fact that I know the head mechanic for a Rolex team who has told me he would put it on with the exhaust for 450.00..well all things considered I think Im going for it..what the heck a little more horsepower for the ol'girl..why not.. Quote Link to comment Share on other sites More sharing options...
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