74goldtarga

I am having a 3.0L turbo track-car engine built and the plan is to use my 8V head which was built by Lindsey to their "Stage 1" spec along with the stock cam and intake. My intention is to run 15psi on E85 (17psi max ?) and max RPM of 6500 with the M-tune (will need a new tune obviously). Car already has a Lindsey stage II intercooler, 3" exhaust with fabspeed down pipe and Tial 44mm waste gate controlled with an E-boost 2.

The question is: is there some head work or a new cam that I should definitely do if I am going to 3.0L?

I realize that upgrading the head/cam/intake is a way to gain some power but I am going above budget already and I want a safe build with a broad power band. I want to make sure I am not strangling the engine in a way that will hurt reliability or so severely limit power that it makes no sense.

Second question: turbo is a custom K27/8 made by Evergreen turbo with a clip on the hot/turbine side to reduce back-pressure for higher boost (when I had the turbo built I told the fellow at Evergreen I was targeting 18psi and this is what he decided would be best). It would seem to me that this is still a decent pairing for a 3.0L at the new target boost of 15psi and keeping the RPM reasonable. Agree?

Humboldtgrin

The head will need the water port modified to fit the 3.0 block if it's not a 2.7 8v head. The turbo should work but may be small on the hot side at higher RPM's if you ever wanted more boost. You can use the same cam as the 2.5 or fine a 9R cam from an 89 2.7 with 1mm more exhaust lobe, not much difference if any is seen. I recommend an exhaust back pressure gauge on the crossover while testing the boost. You don't want the exhaust back pressure PSI to exceed the manifold boost PSI when the turbo is at high boost. Reversion is not good! Other then that get that engine together and show use how it does.

74goldtarga

Thanks. Crossover PSI gauge was already on the list.

refresh951

The head is going to be pretty limiting. I would suggest a late NA camshaft and doing a head like outlined below. It is a low cost solution:

https://rennlist.com/forums/944-turb...t-8v-head.html

74goldtarga

Thanks Shawn - I will read your write-up. I would have to pay to have any work done due to time constraints but I am interested to learn more. My thought was to get the car together and running before next spring and maybe do a full intake/cam/head in a year or two. Any risk of problems with the Lindsey stage 1 head though or just limited performance? I assume not. Also, late NA cam helpful even with my current head? Thanks again.

refresh951

You can always change the head out later. I would try to find a late NA camshaft. It gives a bit more exhaust lift and they are cheap. I found one for $50.

Jay Wellwood

Camshaft Profiles for reference:

333pg333

Quite a different path to what you were thinking of Nathan?

74goldtarga

Actually no. It is what I was originally planning but then talking with Neil had me leaning a different direction. In the end I'm going in the direction that works for my needs and budget. If I had a different starting point I would FOR SURE go with Neil but I wasn't able to re-use as much of what I have with his plan and it also involved a little more disassembly work on my end. I really wish I could build what you are building. I just had too many people telling me to go with sleeves and that didn't fit into my budget with Neil. He is the best though, I'm convinced, and your 2.5 motor is proof enough of that - one of the friendliest / most helpful people I have ever talked to in the car hobby. What I will get should be a nice robust thumper and hopefully meet my needs near my budget.

74goldtarga

My thought was to send him my head in a year or two and let him work his magic.

333pg333

Makes sense to get up and running with an affordable motor and keep the car on the track. Getting caught up in big budget builds can be exciting but also time consuming. Perhaps chip away at building something up in the background over the next few seasons? Can you run the 16v head in your series? If so, that's what I'd work on.

74goldtarga

Thanks Patrick. Like your car, mine started as a street car and has been built for the fun of driving a race-car on track. I have moved at a snails pace compared to you but slowly the car has gotten faster and the increase in displacement will help. Maybe I'll go crazy on the top end later but, as you say, I want to be on track and within (an imaginary) budget by spring. I also need a new helmet, Hans, halo seat before next year and am making some changes to the door bars and graphics. I figured the car should be faster than what it was and if it can do so with reliability I will be happy. For now I am building what I want and can afford rather than for any class or rules-set.

My good buddy has an '07 GT3 and just got to driving faster than me this summer. Maybe this will put me past him . . . Then I can refer him to Neil

333pg333

You're still in the fun part of ownership. Once your project gets really crazy it looses some of the basic fun and becomes a bit of a task sometimes. But to go really fast you do need to make some big improvements over stock. You should be able to give your buddy a good run for his money and even show him your tail again with the larger motor. The extra tq is well worth it!

74goldtarga

The research and learning part of how to make the car faster (engineering) is almost as much fun as the driving for me but in the end the car has to start, run reliably, and go back in the trailer without problems or it gets old very fast. I don't want to change too many things at once. So again - stock head and cam ok even if much less than ideal? K27/8 probably ok for the time being? Maybe 380 whp with this setup or is that overly optimistic?

333pg333

Your parameters sound very safe. Low boost with E85 is a conservative but sensible path. Keeping temps and pressures in check will mean you increase the chance of turning up and racing and towing home again after a satisfying day. Good luck to you.