Maxing out my turbo

[rn240sx]

I currently have 615cc inj with jwt ecu... According to what everyone says, these inj should support a little over 500 crank hp which equates to about ~ 425 whp.

I have a turbonetics t3 turbine stage 3 ex wheel and .48 a/r with a T04B H3 compressor.

If i were to push this turbo to the max.... no wastegate, no bc, just wide open full boost... When it spike's up at 25+ (if it reaches that high), do u think it will reach the limits of these injectors..??

ThanksRobert

[KATwo40]

Most likely you'll reach the limits of the air intake temps and suffer detonation management issues at that boost pressure on your setup before you max out the injectors.

[rn240sx]

Most likely you'll reach the limits of the air intake temps and suffer detonation management issues at that boost pressure on your setup before you max out the injectors.

Im not worried about detonation cause ill be on 110 octane when i do this. I wana see how much pressure it will hold solid.... Then back it off 2-3 pounds and set it there on my boost controller and tune it to that level... and hope i can get about 350-375 whp...

Its just that initial boost spike to however high it will peak out at... i just want to make sure that it wont max the injectors..

[lrb_2000]

can't you slowly raise the boost, and monitor the duty cycle of your injectors until they're almost maxed out, around 90%?

[Rookieca18det]

^+1

[Chezedik]

There is NO T3 that can handle that level of boost w/o reaching the max of adiabatic efficency. For that you go T4 or T25/28. There are not many turbos that do you any good at that level of pressure, w/o it being a BW or Holset.

[SeVa-S13]

I suggest learning how to plot compressor maps and engine CFM rates before undertaking something like that. I did some quick math and while the T04B H3 is a far more capable compressor than I thought (due to its smaller size and age compared to a T04E), 25psi on a 2.4 is beyond the turbos efficiency. Get a bigger turbo.

On a side note: I should look out for a turbo just like yours, I'd never mapped out that compressor before and it's surprisingly efficient, just not at that level.

[C-Kwik]

Injector maxes will correlate quite linearly with the motor's airflow rates. So it would essentially depend on how much airflow there is at the boost level and RPM you project this "spike" to occur.

Frankly speaking it's a rather poor way to try and set your boost level. Running 110 octane is no guarantee against detonation. Making that assumption is a recipe for disaster. If you're serious about trying to put this much boost through a motor, do it in increments on a dyno while measuring A/F ratios.

Between a compressor that will be dropping below 70% efficiency at 25 psi and a puny turbine size given the airflow you will see at that kind of boost, the motor will be working quite hard to pump the turbo. Heat may become an issue. And the power level will probably not be great relative to the level of boost.

[Chezedik]

Similar to mine, although, I would assume H3 refers to the turbine. The turbo will max out at a ratio of 2.5 or 36.74 PSI. This will allow at just over 437 HP. Here is the map I got that from:http://www.rbracing-rsr.com/tu...3.gif

But according to this site:http://www.rbracing-rsr.com/fuelinjectors.htm

your max is about 375 HP.So your max, at any reasonable efficiency would be at 2:1 ratio, or about 29.5 PSI. But that is maxing out your injectors. I would suggest finding a nice comfortable spot at about 320 so you do not need to max your injectors or mechanical potentials. Then you can live safely with boost. And although, you may not make numbers for the KA-t society, you will show that it is reliable, and therefore, worth doing.

[KATwo40]

Before you turn a single screw on any turbo vehicle, I have an even better suggestion than any listed above.

Go to Amazon.com or your local Border's or Barnes & Noble book store and purchase a copy of Corky Bell's "Maximum Boost."

Read it twice. It costs about 25 bucks and you'll never be sorry and you'll never consider finding your peak setup potential this way again.

[rn240sx]

Similar to mine, although, I would assume H3 refers to the turbine.

No the H3 refers to the compressor..

Quote » But that is maxing out your injectors. [/quote]

The 615cc should easily do over 400 whp and the limits should be ~425 whp..

Quote »I would suggest finding a nice comfortable spot at about 320 so you do not need to max your injectors or mechanical potentials. Then you can live safely with boost. And although, you may not make numbers for the KA-t society, you will show that it is reliable, and therefore, worth doing.[/quote]

[KATwo40]

Finding your injector max is pretty easy. cc/min * 0.66 = Approx. max whp on stock pressure.

615*0.66= 405.9

So, you're looking at topping out around 400-420whp, depending on fuel pressure and pump capability (please don't rely on a single Walbro 255).

Also, just because you'll be experimenting (which is what you're doing, rather than actually tuning) with 110 octane in the tank, doesn't mean you won't detonate. ANY fuel can detonate when intake temps reach a dangerous level, which is what you'll be seeing at 25psi on that turbo.

Remember: There are two ways to create boost.

1. Move more air molecules2. Create heat

The first option is your friend. The second is what you'll get.

[rn240sx]

So, you're looking at topping out around 400-420whp, depending on fuel pressure and pump capability (please don't rely on a single Walbro 255).

Why wont a single walbro pump handle that much pressure if im using the stock fpr..??

Quote »ANY fuel can detonate when intake temps reach a dangerous level, which is what you'll be seeing at 25psi on that turbo.[/quote]Well i rather not run 110 octane cause i cant pump it directly into the car. I have to have a separate gas tank with me to do it and thats kinda annoying... Id rather just pull up to the sunoco and pump the 100 octane into my tank directly like im doing now..!!

SO how far would u push this turbo if it was urs..???

[Iamjohnhayes]

show me a compressor map and i shall tell you or at least be able to get reasonable close

[Iamjohnhayes]

alos as far as injectors go....

look at this thread

zerothread?id=109492

[rn240sx]

show me a compressor map and i shall tell you or at least be able to get reasonable close

[KATwo40]

Why wont a single walbro pump handle that much pressure if im using the stock fpr..??

Walbro 255 tops out around 350-375whp. You'd be gettin' pretty close to the max. flow rate of that pump.

[Chezedik]

Found that out when I found the map, I was just a little lit, and didn't bother to fix it. Also, the injector calculation refers to .45 BSFC and 80% DC. So I know that the 240 with DOHC , is .55 BSFC and would reach probably 430 or so at 100% DC. However, I thought we were looking for the safest possible option. I guess that is where I made a mistake.

[rn240sx]

Quote »Walbro 255 tops out around 350-375whp. You'd be gettin' pretty close to the max. flow rate of that pump.[/quote]What is the next step up..??

Another question... How much fuel pressure can the stock ka fuel rail support..???

[KATwo40]

What is the next step up..??

Another question... How much fuel pressure can the stock ka fuel rail support..???

Next step up, if I'm not mistaken, is either dual Walbro 255's or a Supra pump.

As for the fuel rail, it's not a question of pressure. It's a question of flow capacity. There's only so much fuel that can flow through a pipe at a certain diameter, regardless of pressure (past a certain point, anyhow).

You could run a base of 50psi if you wanted, but the flow won't be supported. You'd need to upgrade the rail. Most upgraded rails are designed for top feed injectors.

I think you need to carefully research these points before you do your experiment. The best way for you to achieve your goal would be to make the proper upgrades, then get on a dyno and carefully increase boost and tune the system accordingly until you either A) max out the system, or B) reach your power goal.

[A34D4ME]

From the map a couple of posts up it looks like you will be making heat at that boost level. You'll get pressure from heat but you will not get more oxygen. If you're not getting more oxygen, more fuel isn't going to do you any good.

Looks like you need a bigger turbo.

[rn240sx]

From the map a couple of posts up it looks like you will be making heat at that boost level.

What boost level is that..??

Im at 20 psi now and havent went past it. Im running on 100 octane now all the time. I dont use pump anymore. 110 is leaded and i dont wana deal with buying a new wideband O2 sensor every so many months and i have to carry a gas container to pump 110...

At least with 100, i can just pull up to the pump and pour it in..

[GEO]

Walbro 255 tops out around 350-375whp. You'd be gettin' pretty close to the max. flow rate of that pump.

I don't know about that? Structure240sx is running at 500+ RWHP and has 1 walbro high pressure fuel pump

[Edub1]

Anything above 375 HP according that map. Even the center island is only 75% that looks like an in-efficient unit across the board. Don't mean to bash your stuff but If you're looking for more power it looks like a turbo upgrade is seriously in order.

Edub1=A34D4ME. Sorry for change, damn cookies.

[rn240sx]

Anything above 375 HP according that map. Even the center island is only 75% that looks like an in-efficient unit across the board. Don't mean to bash your stuff but If you're looking for more power it looks like a turbo upgrade is seriously in order.

Edub1=A34D4ME. Sorry for change, damn cookies.

Well i did 314 whp at 20 psi and the wideband they hooked to the muffler was reading in the 8's till about 5k rpm when it leaned out to 11's...

So i know the jwt ecu is flooding the crap out of it. I was gonna tune it but the dyno program they had displayed TIME instead of rpm's... WTF good is that gonna do me..?? They were sitting there guesstimating at what rpm i should me tweaking the afc. And another thing these morons wanted me to keep the a/f ratio in the 8's... He saw how it was steady in the 8's and then leaned out to the 11's and said that is where ur problem is, we need to get to that spot were it leaned out to the 11's and drop it back down to the 8's... I was thinking to myself... Do these idiots know how to tune..??? Rich is one thing, but 8's across the board..!!

I sware i looked at him and told him... "get my car off this dyno, im going home".

Im sure if i get this a/f to about mid 11's across, i could gain another 20+ hp at this pressure level..


Modified by rn240sx at 11:57 AM 1/7/2006

[Chezedik]

I think we covered that, it becomes inefficent at 29lbs. Beyond that, there is no power to be made.

[Edub1]

Look at the map above. Multiply the numbers on the left by 14.7 and subtract 14.7, this is your boost level. Draw a horizontal line. Multiply the bottom numbers times 10, this is roughly your HP. Draw a vertical line. Where these lines meet is the efficiency of your turbo at that boost/flow level. If I remeber correctly you want to stay obove 65% or your overdriving the turbo. At a pressure level 2.5 you are at 22 Lbs so follow the horizontal line to where you hit 65% and that is your wall. At this boost level you're not looking good anywhere. Sorry for the edits, had to re check map a couple of times.

Modified by Edub1 at 11:58 AM 1/7/2006
Modified by Edub1 at 12:02 PM 1/7/2006

[rn240sx]

I think we covered that, it becomes inefficent at 29lbs. Beyond that, there is no power to be made.

Ok, 29 psi from the compressor may be good and all, but i seriously doubt my .48 a/r on the turbine wont allow the compressor to keep its eff at that level... also, i doubt this turbine will even hit 29 psi and if it does, it wont even hold there... Unless someone here can vouch that their .48 turbine did hit and held 29 psi.....

[Chezedik]

Right, also follow the right edge, it is called the choke area. It is called that because the turbo will spin so fast that it will break the speed of sound, and can no longer take in air. You will see a bow, the apex of that bow is the ABSOLUTE maximum amount of air the turbo can move is about 52 pounds mass (429CHP)at about 2.65PR, Which is 38.955 PSI. However given the small range of efficency, that air would be hot enough to cook your skin off if you did not have a MASSIVE IC. So, what we are saying is the maximum boost level at good efficiency is 2.1PR (30.87PSI), for about 47.5 pounds mass (392.4 CHP). Meaning that you can only hope to gain about 30HP for raising your boost 8 psi. And as inefficient as it would get I would be surprised if you did not LOSE HP.Also, Edub, you do not necessarily subtract 14.7. Just if you are looking at PRs under 1. Obviously, if the PR you are mapping for is 3 then it is three atmospheres or 3*14.7 = 44.1PSI at sea level.

[Chezedik]

And no, I think you are right, I would be surprised to hear that the .48 A/R turbine will move that amount of exhaust past it without creeping BAD. So you would be looking at less than 20PSI, and I think that is generous. A turbo upgrade would be where you want to be for above 300HP.