So did a dyno tune on my car. I tuned the car.......i made 573awhp on pump and some meth, at 30psi. I was expecting alot more.......
My turbos are twin gt3076r with .48 exhaust and .60 on compressor could the .48 rob that much power? Is it cause im so much above sealevel that the air is this thin that its that much of a difference?
my heads are ips race heads 1mm over so theres tons of flow
90mmintake 90mmthrottle body
The dyno was a dyno jet, any gurus suggest anything thanks.
I'm hoping you find your issue since there is definitely something wrong... My car made more power (608whp) through TD04s and stock heads/cams at the same boost. That's going to be a pretty large boost leak. One trick I've used is to put some max hold hairspray on the intercooler pipes before you put them into the coupler. It helps to seal them and has allowed me to run 30+psi with an eBay intercooler set up. Good luck.
x2. OP, you can't go based on FEEL if the car is running how it should be...yeah to a certain extent you can feel if the car is knocking or not...but your standard of judgement keeps swaying.
I just seen this bent Ic pipe on the cold side out and it looks like it could leak a lot of boost I'm going as we speak to get it pressure tested and possibly leak down test.
I'll take a video of car running or boosting lol. ?
Did boost leak there was a hissing noise on bov at 5psi fixed that up and boosting to 24psi coulve go much past since i was flying once again. Last night only got to 20......
But as far as mechanical everything is good. So it looks like its the degreee..... Or just f with the cam gears
This was a worthwhile read filled with a lot of helpful, informative posts! I must say that threads like these make me glad to be a part of this community! Good luck with your build-- I hope it all works out.
I was just in the exact same position. Made 570awhp with my hx52 at 30psi on pump/meth. I went round and round and here is what I found. This may or may not be your problem.
I found that my exhaust system had 8psi of back pressure, added a 46mm wg to the downpipe to test and it dropped to 2psi.
I found low compression on cylinder 6. Turned out one of my guides had broken (no clue) and bent both exhaust valves. The cylinder wasn't dead, but obviously a problem.
I did a leakdown test and nothing was leaking...........just a bit past the piston rings......nothing to worry about man. I have no freakin clue what to do now maybe just my setup makes that much who knows?
All and all this car is really getting on my nerves, fuse 11 keeps blowing now so no dash lights windows turn signals etc....... gotta find the issue there now.... Was hopeing to hit the track tommorow but doesnt look like it unless i get this problem solved...
I would still hook into the exhaust and see what the back pressure is. If you do some searching there was a supra they tested dp/exhaust sizing and gains were 30-80rwhp, another dsm gained 75awhp by adding a cutout in the dp.
I just used a o2 plug, drilled a hole through it and welded an air fitting nipple on. Screwed into a spare o2 port and hooked up a boost gauge.
May or may not give you big gains but in the scheme of things it is pretty easy and cheap to add a cutout.
The gauge isn't the biggest problem as you can run a bunch of tubing to keep it away from a lot of the heat. The hose that is hooked to the exhaust is the area that needs to be capable of withstanding some heat. Good rubber hose should do the trick as it isn't a permanent item.
Hook it up, do a pull real quick, and analyze the result. Return it back to the original configuration.
Op, do you have any form of catalytic converter on the car? Is there a muffler?
Yeah, I doubt it's that....pretty sure with very little modification even the stock stuff has made into the high 600 low 700. I still think it's the cams. But what about the clutch? Could it be slipping under high boost and messing with your numbers?
Ive got a rps twin carbon it probably isnt the clutch. I think your right when you say its in the cams.
Been thinking ive heard of guy losing 50hp at just 7psi cause of improper degreed cams. And id imagine it works like this so say your makeing 100hp you lose 20hp cause cams arent degreed properly id imagine that percentage would still account on say a 1000hp setup so thatd be 200hp see what im saying? So for people just to say ahhh 40whp is all youll lost doesnt make sense to me. I think as the numbers increase youll lose alot more so i think your spot on dciv.........i jus tneed to learn how to degree which probably wont happen.
Could have slightly bent valves in cylinder 6 then... And the compression numbers could very easily point to a cam degree problem... If you have different compression on the 2 banks then one or more cams is probably off
yah no.......to bad my car is from japan and usa doesnt allow jdm cars unless there 25 years old cause i was gunna do that in the get go.....Or get nelson to build me one but i called ur borders and stuff they said no i need to make a bond and all this crap that was loads of $$$$$ so i said f it.
The leak down test shows the cylinders ability to seal with the valves closed. A compression test will show how the cylinder is operating. You can have good leak down numbers and poor compression.
Hooking a boost gauge to the exhaust won't cause any problems from heat. At least not in the short term. I was a little surprised. I drove around for 10 minutes and 6 pulls, no signs of melting, not even where the rubber hose hooked to the exhaust.
Pull all 6 spark plugs out. Make sure the battery is fully charged. You need to disable the fuel system. Test each cylinder one at a time. When you install the compression tester in a cylinder crank the engine, you will hear an audible sound each time the cylinder being tested runs a compression stroke. Count the number of compression strokes while cranking. I usually crank 8 or 10. Stop cranking and check the compression. Do this for all 6 cylinders.
If any are lower than the rest add a table spoon of oil into that cylinder and test it again. If adding oil raises the compression then it is a problem with the piston rings. If the reading doesn't change it is a problem with the valves. If all cylinders or one bank of cylinders is low it is probably a problem with the cams or timing.
Were your cams supposed to have shims under the lifters?
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