Jump to content
SAU Community

Recommended Posts

sounds on the money to me. i wouldnt get your hopes up to much. any rb25 making close to 400kw on a gt35 is very stout. hell my 26 only made 376 on 25pound with a t04z...

i thought the t04z make big power on rb26's?

my rb26/30 is making 405awkw (equivalent to 445rwkw) on low mount garrett -10s @ only 23psi

Had a chat to Adam again tonight.

And he said the dump and new cooler would be the best place to start.

I asked how many cars he had tuned making 400+ with a 3 inch dump and he said none.

Not saying there are not engines out there doing this. But if he says he has not seen one then there must be a reason.

For the exhaust its a 5min test, pull the 02 sensor and fit a brass adapter and vac nipple, hook the second map sensor in to it and plot it.... bingo done.

i remember talking to rob @ rips about my exhaust which is a hks super dragger (starts @ 3.25" then goes to 3.75" at the rear).

his feedback "run it with the full exhaust then drop it at the front pipes, you will then know if your exhaust is choking any power"

^^^^ How do the above two posts address whether the dump is the issue....what you have described is usefull for determining whether you have backpressure in the exhaust....not whether you have the proper gas expansion off the turbine?

If you go back to my previous post with two excerpts I cut and posted...refer to the first one...now this guy had a 3 inch dump going to a 3.5 inch side pipe...now I doubt there would be any backpressure present in this system....yet his hp was falling over. He then fitted a 4 inch dump and 3.5 inch full street exhaust and abracabra he made more power everywhere.....and if you read his post weren't not talking massive hp figures here either.

For your convenience:

Dropped the exhaust, still with the 3 inch dump pipe tho, could run an extra 7 deg timing (up to 22) and made 450 at 24psi. Now this was ok, except when we added gas, Power would spike to 490 then as the CFM increased power would always drop back to around 450 rwhp. This was with a 3 inch dump pipe, then increasing to 3.5 inch and exiting out the side of the car. It didnt seem to matter what we did with camshaft timing or anything else for that matter power always fell over hard.

So off to the drag strip, did what we needed to do with the car...... Afterwards a new full street exhaust was made, with a 4 inch dump and a full 3.5 inch system. This thing now makes more over all horse power than before with a 3 inch dump and side pipe but now makes more horse power the harder we rev the engine. Everything here has been done with a screamer pipe, So you could imagine the added stress with CFM having it plumbed back in.

Edited by juggernaut1
...and replace the 4 inch body cat with a 5 inch body cat.

agree with that too.

juggernaut is on the right track. :( yes it's good to keep heat in the pipe to keep the energy in there and keep the gas velocity high BUT you also want to allow the gas to expand nice and quickly once it's past the turbo outlet. you need to for POWER!

^^^^ How do the above two posts address whether the dump is the issue....what you have described is usefull for determining whether you have backpressure in the exhaust....not whether you have the proper gas expansion off the turbine?

agreed i should have read the whole thread :P but depending on the type dump it can still be usefull, if it is a straight through pipe then no it is a useless test, but if it is a chamber type with the usual 3 bolt flange (and 02 sensor bung placement) it will still show up any restriction, even with the exhaust dropped. We just used this to sort a restriction in a s15 that had a dodgy china split dump, then tested the tomei and CES (tomei was the pick).

  • 2 weeks later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Nah. Was just wondering if you were having a small stroke or if there was some slur/gaf/inside joke that I wasn't aware of.
    • That was a fark up, it's Salamanca Place I was thinking of. And now I'm curious as to what potential slur/gaf I have caused with Salamander Road, ha ha!
    • Actually everyone on the roads was really well behaved. The only person that did any minor tailgating was a local hoon in a Turbo Focus. Unfortunately we weren't going the same way so there was no grand initial D touge battle. Lots of people pulled over and let me through. The amount of "Hey man nice car, omg skyline, nice 34 man woo" was suprising. Like really suprising. Like almost annoying. My partner was obviously surprised, she'd never seen anyone in the real world point out the car/like the car/want to chat about the car before, so to have like 3 people per day mention it was notable, I could finally say SEE? SOMEONE THINKS THEY'RE COOL. Everyone was also pretty suprised about the weather. Every day was dry and about ~13-14C. Mount Wellington had a sign that said they close the gates at 9pm and I was heading up there at about ~7:30. It was VERY apparent that conditions were getting significantly worse by the minute on the way up and down. The road on the mountain was terrible though, it's no driving road. I have various suspension related questions now. Luckily it was only about 20 minutes from where we were staying to the top of the mountain as said Google maps. We only had the 2 nights in Hobart. We went to the Farm Gate Market though which was really good - And went down to the Hastings Thermal springs/caves down there during the day. I'd definitely be up for going back again, so luckily there's a few more sights yet to see. Didn't get to do the west coast/queenstown/cradle mountain so this was supposed to be a 'scouting' trip anyway of sorts if I were to one day do/take part in/organize a more car-focused trip. As for the boat, it wasn't bad. Well it was bad, but not in the way you're thinking. We did the night trip which leaves at 6:45 (though you have to be there ~2 hours earlier) and arrives the next morning at about 6am. There is nothing to do on the ship. If you plan accordingly and bring a book/tablet/show to watch/charger you can just chill out, take some Travacalm and just sleep through it. The food there is an extremely basic buffet that costs $32 a plate, or $14 for a $3 pizza. The way back we had a travel kettle and a few different types of cup noodles and made our own tea/coffee in the room. This was a far superior way to do it. At the very least book one of the rooms with beds. I guess as we were in the off season we didn't have room mates. You get an option for rooms with 4 beds (2x bunks) or a room with just the two bottom beds. There's also some option for a deluxe queen bed but it's much pricer. We've been on sleeper trains in Asia before so we figured this is similar (and it was)
    • You just gotta be really, really, really clear and decisive with what you want your end product to be. 99% of people who want this conversion aren't "I want to run a 295 front tyre!" so they don't really need the widebody. They just want the OEM body to look a little less dumpy, so bonnet, bar, skirts job done with some camber, stretch, slam. It's when you want that, but then decide to pivot later you get big problems. See also if you're willing to get an all in one fibreglass bar, and you're willing to accept fibreglass problems like cracking the entire item on a driveway, instead of just a piece attached to the bottom, etc etc etc. Decide this all before buyin'.
×
×
  • Create New...