So earlier this year I had a 2.4LR built by Evolution Dynamics. I'm trying to decide what's the right amount of boost to run for my application.
Basically I want to ensure longevity out the motor. The car is not my DD, and I don't beat on it. I'm currently running
basic specs:
-2.4LR
-Built & ported head(supertech valves, retainers, beehive springs, ARP studs)
-9.5:1 CP Pistons
-Manley TT Rods(I beams)
-ACL main&rod Bearings
-6466 G2 (1.32 A/R)
-Twin Scroll manifold
-Twin 44mm Tial
-Double Pumper(FB290s),2150cc FICs
-Speed Density
-Exedy Triple
-Stock 5spd
-E85

I've been running it on a 25psi(550whp, dynojet) map for a few thousand miles now.
My builder is insistent that I should come back and get a 2nd-higher boost map.
As much as I'd like to i'm very hesitant because i'm not sure what effect it'll have on the life of the motor.

I realize there's ALOT of variables at play here. But considering all proper maintenance is done, a good tune, and a watchful eye is kept on the logs..
what's your opinions on a "safe" amount of boost I can run?
I don't launch the car, I basically stick to 2/3/4th gear highway pulls in mexico..

The motor currently runs healthy, burned/blew-by less than an 1/4th a quart of oil in the first 4k miles. There was an issue with a cracked and miss-gapped plugs giving me problems for a couple thousand miles, but that's all.

 

If it has an exceptional tune it should hold upwards of 800 wheel dynojet although I don't recommend running it at those power levels all the time. I'd assume there is 626+ rod bolts on ur setup.
I would prefer a lighter rod like pro H which would be easier on the bearings, anyway if the tune is good it will be fine.
Just to give an example there are quiet a few evos down here running upwards of 600 wheel dynojet on stock evo blocks.
Mostly important make sure ur block was assembled with the correct clearances for that kind of boost / power, being that is a LR and if it has good bolt upgrade u should be fine in the rpm department.

 

-yes it has the 625+ rod bolts & L19 head studs. Rev limiter is it 8k. Clearances were checked and recorded during the build. I plan on checking the bearings & sending in the injectors to get cleaned once it hits the 10k mile mark. I'll probably get an AMS oil pan at that point too.
-I realize that 25psi isn't much for a built motor.. But regardless 550awhp seems like alot for a 4cylinder...
I'm considering just doing a 30psi "kill tune", and that's as far as I'll probably go.

 

There's really no point to having that 6466 strapped on there if you're going to leave it at 550. Having a high boost map to occasionally play with at around 775-800whp would be fine. If your set up is good, ~35psi will put you there.

 

i'm also concerned about the kind of stress that'll put on my stock Tranny/Tcase. Yes I won't be launching it, but that doesn't mean the synchros & forks will be happy when shifting with that much power. I'm already getting a little bit of grinding from 5th to 4th, with only 22k on the 5spd

 

If your not launching it or beating it up while shifting u shouldn't have a problem, if there is no drag on clutch and its setup right and are shifting good u shouldn't have to worry about your transmission or t case while shifting at high boost / rpm...
And youe not shifting at that power level, your shifting at a certain RPM. If the shift is good then when the pressure plate slams the clutch into the flywheel the trans is already in gear and the gears should hold the power no problem...

 

HP has no effect on shifting. RPM does, but your 2.4 only spins 8k. Launching is what hurts the tcase.

 

i'm thinking i'll go with a 30-32 map. #35/700+ is just too close to the limits of several components for my liking. In my head it just increases the chances of something failing catastrophically a bit too much.

 

Don't think there is any better than super tech valve train, just curious what crankshaft is in there?

 

100mm crank. I thought the same too, until I met someone who worked at a reputable local machine shop who said they stopped using supertech because of too many valve failures.

 

What components? You do realize that the "best" built trans and tcase available is from TRE, and he uses the stock gears, shift forks, and synchro's. These are parts that people make 900whp with. You are seriously underestimating the strength of the Evo drivetrain. Especially since you're not launching the car.

 

I suppose the drivertrain should hold up as long as I don't launch it.
I'm going in this weekend for a 30psi map. I suspect it'll make atleast 600awhp on the dynojet....thats ~150hp/cyl(more if we account for drivertrain loss). In my head that just seems nuts, considering the stock car came with about half that

I'm curious what usually kills these motors first at these kinds of power levels. Heat warping block/head, valvetrain failure, bearings, rods?

 

Detonation. Go read the struggles to make aero engines produce more horsepower during WWII. It took a decade to perfect a new aero engine so they worked with what they had - 130 octane fuel, anti detonation fluid (water or water and methanol), intercoolers (the name comes from the fact that the cooler was between the first and second stages of the supercharger), turbos, oil coolers - its all there. Add in the fact that aircraft were also often seeking long range which required lean mixtures. It was easy to get something wrong and make it a one way trip.

 

Git-er-done is right it seems like a waste not turning it up. 35 psi is a safe limit and shouldn't hurt your motor if its been built for it. Once you get over 40psi on E85 things have to be just perfect with the tune. Your at 9.5:1 so that's about the limit, any more boost and you have to start pulling a lot of timing. What oil are you running?

As far as the drive train if your not launching the you'll be fine. Just remember the T-cases will fail at this level if your not changing your gear lube very frequently. Everybody is going out and buying "indestructible T-cases" because they had a failure, well let me tell ya most fail because the gear lube was toast not because they overpowered the unit. There really is no way to exceed the torque limit on the transfer case with street tires so when you see a failure on a car that doesn't run slicks, you know it usually was improper maintenance. I suggest you get a well rebuilt T-case and change your gear lube frequently. Same goes for the transmission and rear end. just change the lube about half as often. No need for the "soft gears" on a car that doesn't launch.

You should have no problems running 750hp if properly maintained.

Cheers, 2win

 

Yeah, Fluids should be changed at <10k mile intervals at this level, or just annually if the car doesn't get driven a lot.