djbit Posted June 11, 2008 Share Posted June 11, 2008 I'm debating which route to take on turbo. t3/t4, t4, hy35(w), or hx35(w) , others? I don't want to blow my engine but my goal is 350-450 HP. The car does have a worked p90a head. Should I get the 2mm head gasket to help to lower compression? The car has ~4000 miles on a fully rebuilt engine (how a bought it). I don't know what pistons it has, most likely, the l28na oem Flat tops. What do you guys recommend? Thanks Quote Link to comment Share on other sites More sharing options...
datman Posted June 11, 2008 Share Posted June 11, 2008 I have a pretty much stock NA f54/p90 with flat tops and 2mm gasket. I run a Holset HE351CW and it's very quick @ 15psi boost. Responsive low down and bags of torque. Go for it!! you won't look back. Quote Link to comment Share on other sites More sharing options...
djbit Posted June 12, 2008 Author Share Posted June 12, 2008 Thanks man! Is HKS the only company that sell the 2mm head gasket? It's pretty pricey but yeah, it's very motivating that others have been successful going NA to turbo. I'll be looking out for a good holset turbo but I will probably be able to afford it until July. Quote Link to comment Share on other sites More sharing options...
djbit Posted July 18, 2008 Author Share Posted July 18, 2008 Got a Holset HX35W and a 24X12X3 FMIC (a la bigphill). Still need surge tank, both fuel pumps, fuel regulator, megaquirt and all the valves and tubing......I'll get there eventually....someday. In the mean time I am still driving my car with the dual SUs and it is running great. Quote Link to comment Share on other sites More sharing options...
Pyro Posted July 18, 2008 Share Posted July 18, 2008 T04E -50 trim compressor seems to be the best fit for a L28. You will need a 1/2" spacer on the stock exhaust manifold for the compressor to clear the exhaust manifold. A T3 turbine works well with a L28. Plus if you use a T3 turbine, then you can use the stock wastegate and down pipe (if you are on a budget). Leave the turbine stock if you use the stock cam. If you use a MSA stage 1 turbo cam, then get the turbine modified to a stage 2 or 3. A stage 3 will hit full boost by 3500. With higher compression, a longer duration cam (like the msa stage 1 turbo cam) will help prevent detonation. Quote Link to comment Share on other sites More sharing options...
rvandivort Posted July 23, 2008 Share Posted July 23, 2008 Leave the original cam in the head. Don`t change it, they are good for 350+. See other threads here. Na is different than turbocharged for obvious reasons. Quote Link to comment Share on other sites More sharing options...
djbit Posted July 28, 2008 Author Share Posted July 28, 2008 My Z came with some type of cam. I will take pictures of it when I install the turbo valve cover. I'm hoping someone will be able to give me an idea of the type of cam it is. Leave the original cam in the head. Don`t change it, they are good for 350+. See other threads here. Na is different than turbocharged for obvious reasons. Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted July 29, 2008 Share Posted July 29, 2008 My Z came with some type of cam. I will take pictures of it when I install the turbo valve cover. I'm hoping someone will be able to give me an idea of the type of cam it is. I think it's probably a pretty good assumption that it's a cam for normal aspiration. It probably won't like turbo. Quote Link to comment Share on other sites More sharing options...
djbit Posted July 29, 2008 Author Share Posted July 29, 2008 Yes, your probably right. I'll be on the look out for a turbo friendly cam. Any idea who makes good turbo cams for a street car? Depending on funds, I may just make the turbo set up work as it is with safe boost just so I can go through the exercise (I need the experience). I think it's probably a pretty good assumption that it's a cam for normal aspiration. It probably won't like turbo. Quote Link to comment Share on other sites More sharing options...
Pyro Posted July 29, 2008 Share Posted July 29, 2008 Yes, your probably right. I'll be on the look out for a turbo friendly cam. Any idea who makes good turbo cams for a street car? Depending on funds, I may just make the turbo set up work as it is with safe boost just so I can go through the exercise (I need the experience). The turbo setup and cam should match. A low rpm boosting turbine is restrictive. And this restriction makes a lot of exhaust manifold pressure which doesn't like cams with valve overlap due to excessive reversion (exhaust flowing into the intake manifold). So, turbo cams typically have wide lobe separation to reduce the amount of overlap. However, free flowing turbines have much less restriction which lowers exhaust manifold pressure. And valve overlap is not a problem if the exhaust pressure is less than the intake pressure. But the free flowing turbines spool up much later. These turbines do well with normal NA cam prolifes. A stock L28 NA cam doesn't have that much more over lap than a stock turbo cam. It does have 8 more degrees of intake duration which is good for another 500 to 750 rpm of usable power. And using an aftermarket down pipe and bigger exhaust should help the stock turbine flow well enough to use a stock NA cam. I use a MSA stage 1 turbo cam. Has 260 intake, 250 exhaust, and 114 LSA. pulls hard to 6700 rpms. I use a stage 3 T3 turbine which doesn't hit full boost until 3500 rpms. If I had to do it all over again. I would use a NA cam (248/248 degrees) with a stock turbine and aftermarket down pipe. Then use a T04E-50 trim compressor. Quote Link to comment Share on other sites More sharing options...
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