i have a s4 stockport rebuild engine on my TII and i m lookin for some estimates on how much power i might make on my setup...

i have a stock port s4 block with 3mm seals greddy cast manifold greddy FMIC im running a HKS T04R turbo with .84 AR hot side i have 1600 secondaries and 850 primaries.. kg rails and full SS lines with a walbro pump and im running a microtech lt 10.
Does anyone have any idea of what kinda WHP i may put down with this setup?

 

375 @ 15 psi.

Your stock ports, log undivided manifold and divided turbine are holding your back. Turn the wick up to 20 psi or higher with some water or alco injection or race gas and your closer to 450~480.

~Mike........

 

how much more would i be making with a better manifold and a streetport?

 

i'm gonna say 380whp@15psi


stock ports for the lose

 

I doubt you would see 480 @20lbs with a .85 hotside on stock ports.

 

I would think he needs a .96 or even 1.0 divided hotside for those numbers.

 

^^ last two responses

Kabooski made:

520 rwhp with a .81 A/R P-trim, PT67 15~18 psi


carx7 made:

467 HP .84 A/R divided 15~18 psi PT67 GTQ turbine


Carl Byck made:

506 RWHP/387Torque @ 25 psi, 449/332 @ 20 psi .81 p-trim
https://www.rx7club.com/showthread.p...highlight=carl

Theres many more, but you get the point. If you want to see more people who has eclipsed the 450 mark on these lower A/R turbines, LOOK and SEARCh, theres pleanty. .81, ,.84 isn't the bottle neck. Its ports, intercooler, and exhaust system amongst other details. These "small" turbine A/R's you'll find have good response and anything bigger then 1.00 your just not going to see much power increase untill you start breaking the high 600 figures, at that point its either a dyno queen or drag car and response isn't a major concern.


The manifold isn't a huge deal, especially when you consider the cost of either making or buying a tubular equal length long tube divided manifold. The main benefits of them is quicker spool up. Since you gain a quicker spool up, you can go bigger on the turbo and make more power yet be as responsive as a log manifold with a smaller turbo. With a street port mild to large, expect a 30~40 increase in power at the levels we were talking about (T04r at about 1 bar). Porting shows more gains the bigger you go with the turbo or pressure ratio/boost amount. You should match a non divided turbine with a non divided manifold / divided manifold and divided turbine. Your .84 A/R is divided, your HKS manifold isn't. Although it'll work fine, your spool up may be a bit slow and eventually your center divider in the turbine housing will develope cracks. Personally I'd either take the big plunge and splurge on a nice divided tubular manifold (read; I said NICE, not SSAutoCrapper) to go along with your turbine, or get either a .81 or .96 non divided turbine housing to match your HKS manifold. BUT, like I said already, the .84 you have will work, jusy be a little slow on spool up due to it being divided and your manifold not.

~Mike............

 

thanks alot for all the info man you've been a big help...i dont think exhaust and intercooler will ever be a problem for me cause im running the HUGE greddy kit from rx7 store..and im running the 3 inch racing beat exhaust..i would think the two would easily support 600+ whp..is it bad that im running a dry center turbo considering the fact that i am goin to be driving this thing on the street as well as on the track?

 

Nothing wrong with a dry center, although I always recommend getting a wet and every turbo I've built and sold for rotary guys has been wet as well. In general, wet can last anywere from 1/4 to twice (200%) as long as a dry center dependant on useage and the driver (if if lets the system cool/run before shut down and how often oils changed and grade oil).

~Mike.............

 

Kabooski made 520whp @20psi on racegas, not 15~18 or whatever that means

carx7 made 467whp @19psi on racegas, not 15~18psi


don't be giving this guy false hope that a 67mm T4 will pump out enough air to hit 500whp on pumpgas or something. it probably wouldn't even happen with big ports, let alone stock ports...

 

jacobcartmill: the racegas doesnt give you the power, it simply lowers your chance of detonation. kabooski's use of racegas is not the reason he made those numbers, the racegas is a safety measure against detonation.

only difference between higher octane gas is speed of burn.

kevin.

 

You obviously haven’t read ANYTHING, or at least comprehend a damn thing I have posted. Your quote of me was for the two previous post before that I was responding too, I was given examples of guys making over 480 rwhp with smaller .81, .84 turbine housings. It had NOTHING to due with the original posters questions on power levels or PORTS, or PUMP GAS. Now for the original posters questions, I said 375 @ 15 psi didn't I???? ahh wait.. scroll up.. damn yup sure did. Then I said closer to 450~480 running meth injection and or water injection running 20 psi OR HIGHER boost. All this was posted too long ago for me to edit it before this now current response. No one reads jack **** anymore on these forums, just skims them fast looking for a chance to pounce on others.


~Mike..............

 

Pay Attention

He is spot on, good tune, right parts, 450+whp at 20+psi on stock ports with that turbo is not out of touch with reality.

-S-

 

haven't you heard??? Everyone is an expert on the internet

 

teknics: thanks, i am aware how gasoline and octanes work.
they made those higher WHP numbers because they were able to run higher boost (19 and 20psi) due to their use of race gas. neither of them would have been able (maybe? or maybe shouldnt have been able) to run that boost or make quite those numbers without the use of higher octane -thats the point i was trying to make.

 

mike: stop crying. i made a mistake and did not read the two posts above yours, which were about turbine sizing.
and i "pounced" on the wrong boost levels you cited when talking about kabooski and carx7's dyno numbers. you specified that they were both running the same compressor; i mistakenly thought you were talking about the compressor power potential instead of turbine potential/restriction.
sorry for ruining your week.

FWIW, i agree with you. i had a 1.15 a/r ptrim on my t04b vtrim turbo (yeah, mismatched i know). i lost absolutely no top-end power when i swapped out to a .81 p-trim turbine housing and it only made the car faster, due to the much better boost response and spool time. there's no need to go over .8x in turbine a/r (especially if its an aggressive turbine wheel) unless you have over 550whp because the minimal topend power gains probably wont outweigh the loss of boost response

 

I had a full tank of 91 pump gas when I did my initial tunning. I added a few gallons of 100 octane to the car when we did the 19psi runs. So at best I was in the mid/low 90's octane wise. I guess it depends on ones definition of race gas. But I suspect my overall octane wasn't too far off from the 93 available in Tx and other states. (didn't pay attention to the location of the original poster)

I realized later that under load my AFR's were in 9's when we did this tunning.... SUPER rich.

*edit* I should also add, since I"m not sure I ever made it public... that once I blew my motor, and started looking at the trashed turbo... it was infact a PT68 instead of the 67 that I had purchased.... lol. Never thought to actually measure the compressor when I purchased the turbo to be sure that I had indeed recieved what I had purchased. oops

 

ah thanks for the info, i didnt even know you posted on here anymore...
what compression rotors were you using in that car? 19psi seems a little ballsy on 93 octane, but what do i know? everyone in here thinks i'm "just another 'expert' on the internet."
do you still even have the car? i noticed the numbers were from forever ago. i remember ooing and ahhing at that car back when i had my FC's a couple years ago.

 

nice expertise shown with that valuable post too, turbo-travis.
do you have an rx7? have you had an rx7 with EMS and a T4?

 

i think people ussualy assume that if someone is running over 15 psi that they either have meth injection or they are running race gas..its not very smart not to

 

I am not sure what you people do over there but there is BIG differences in exhaust back pressure and resulting volumetric efficiencies on the engine when you go from a very small turbine housing like a 0.8X to a 1.3X on a T4 frame turbo.

You only need to look at garrett's own HP ratings of certain modles of turbo chargers to see that they shift the power potential of the turbo higher and higher the more favourable this condition is (exhaust back pressure to compressor inlet pressure). There is case after case of people here getting BIG power gains in revs from 5k to 8k rpm @ sub 1.5bar boost pressures when switching to suitable sized turbine housings.

A 1.15 divided is considered small here on a TO4Z ! (modern q trim type turbine)
on old technology p trim turbines (TO4S,TO4R etc) we all use 1.32a/r's and have near flat power peaks from 5.5k to 8k (honest 600bhp engines @ 1.3 bar 21 psi !) so there is no lack of power band or responce and no shortage of power either. If you want big power from 4k or 3k go put a v8 in your car the smaller turbine housings will give you responce but it all comes at a cost and that cost is worse operating conditions for you engine.

 

Don't bother telling these guys that stuff.
Its pretty obvious don't to many people monitor preturbine backpressure...

 

I'm around, but messing with FD's now. The car had 9:1 comp rotors. I drove the car around at 17psi. The 19 was pretty much at the dyno. Agreed it was ballsy. But the car was very solid. We quit tunning when i ran out of fuel (single supra pump). I sold the chassis a few years back... the new owner put an LS1 in it.

Please don't insult my abilites or intelligence. I am well aware of what I was doing. I haven't looked recently, but when I sold my FC, I hadn't seen any *acutal* dyno's from anything you'd done....just alot of talk and hype. Please link me to the dyno graph where your self built turbo/manifold/setup dynoed 470 on pump. And then the date that said you did it 5 years ago. It easy to lay claim to numbers years after other people did it.

Peter brings up an interesting point, and I have always noticed that the Aussie's run "large" turbine housings... or at least certainly larger than what "we American's" run. I've seen plenty of very respectable people on this forum with FAR broader expereince than I run small turbine housings and make big power.
I only had funds to try one setup, so I made my decision based on the research that I did on this forum.

As to back pressure, I played with my theory (and no, I am not claiming it to be original) that a small turbine housing, with a big wheel (GTQ), and a 4" exhaust, would reduce the back pressure enough to promote acceptable power in a good power band. The backpressure on the top end was "bled" off (by what many considered to be overkill for my setup) with dual 38mm WG's. I thought my boost response was plenty sufficient, and for my first car and build, I was please with 470RWHP.

 

Holy thread resurrection batman!! haha..sorry to bump this antique thread but i figured it'd be dumb to make another on a similar topic.. i ended up putting down 380 whp @ 15psi. i didn't have meth or race gas available at the time so we didn't tune for anymore boost.

so now ive been running the same setup for 2 years and im in the quest for more power, i purchased a coolingmist deluxe meth injection kit with the vari cool progressive controller, im making an appointment with my tuner to get it tuned to make, i hope at least 425 whp. im thinking around 20psi to be able to reach around 425whp, correct?

i now have a koyo rad, supra TT pump and ported TB with plates removed, also precat removed from RB exhaust system. how much boost do you guys think ill need to bring me from 380whp to around the 425whp range?

 

anyone? im getting ready to go get this thing tuned so im hoping for some help before then, thanks