20psi on pump gas, if you dont know, dont answer...

[Doward]

Ian, your setup is a bit over and beyond what Jake's setting up With your head and camshaft, I'd be interested in seeing your VE across the board.

I wouldn't be the least bit suprised to find that your setup works better with the 3" piping - I certainly don't know enough about it to make an educated guess

That said, Jake, I'd stay with the 3" - changing the size from 2.5" out the turbo to 2.75" into the IC (3") then 3" all the way out might work out well - but I wouldn't go spending money to do so (aka, if you have the 3", use it - you will certainly not be hindering performance doing so)

Zazzn's hit the nail on the head - without an accurate map of your volumetric efficiency, you can't accurately nail down exactly what would perform best.

In your shoes Jake, I would stay with the 3", if that's what you already have.

BTW, all my research says teh PT67/T04r/T04z use the GT wheel It's why the PT67 makes so much more power than the old school T66.

As for my AFRs, I like 11.5-11.8 on the street and at the track. I don't like the extra cylinder pressure from the hotter mixture

 

[starscream5000]

Ian's turbo is also a ball bearing turbo, so boost comes on significatly sooner than a regular turbo, less resistance to spin the turbine .

Jake, turbo or not, flow charateristics through a tube are the same when it comes to velocity, turbos just increase it even more .

 

[QWIKSTRIKE]

I have a T61 setup similar to your build and i was running 20psi on pump gas for about 2 months. Now i'm rebuilding my motor because i detonated my #6 piston. I talked to Larry at SP and he said 20psi and pump gas are a big nono. Not sure about yours being a bigger turbo but my experience is going to be expensive. I would definitely mix some cam 2 or some kind of race gas to up the octance and that boost shit doesn't do a damn thing. And this happened to me within the last month.

Yeah and what was the tune....I bet the WOT AFR's were over 11.2. You guys fail to realize tuning is the key. Detonation isnt caused by bring riched its caused by being lean. Lean meaning not enough gas or gas tuned out of the equation by leaning the mixture for better performance. I bet if you ran 20 lbs of boost at say 11.0 WOT you would not have dotonated. Waht Larry didnt tell you is that your AFRS were to lean. I have plenty of friends running 600RWHP on t78s wiich by the way a 67mm turbo. Tune for a conservative AFR and it's atainable on pump! Again how many people have you seen detonate while rich.

 

[QWIKSTRIKE]

Ian's turbo is also a ball bearing turbo, so boost comes on significatly sooner than a regular turbo, less resistance to spin the turbine .

Jake, turbo or not, flow charateristics through a tube are the same when it comes to velocity, turbos just increase it even more .

Reigns turbo is ball bering and so is my turbo that I am running now. Also I just want to add that my 475RWHP was done on the GT4088 turbo. Now I have a GT4067R since the winter. Seems like that straw to a garden hose to a large pipe just took a twist. The size of the turbo filling that large pipe is the key. Ians turbo is smaller than ours as I recall yet going to the three inch pipe increased the response of the spool. Spool response was "QWIKKER" with the 3" turbo out pipe IMHO because the outlet on the turbo is not bottle necked with the out put of high air velocity at the opening before the IC.This seems to support what I was saying all along. The larger pipe is like a 5 lane highway that lets the velocity of air travel faster because of the larger opening. Proof positive that the 3" piping is good on this setup ie 3.0 litre engine and 500rwhp turbo power and 3" piping is a go!:naughty: :biglaugh: In the computer world a risc processor running at half the speed can out perform a cisc processor at 2x the speed. But when the basic input out put travel ways ie the bus routing(Highway in and out) was increased the cisc began to catch up and now is faster than the risc. In other words the larger the highway for information to travel from the computer the faster the response time. The same theory is happening here, and Ian, and I seem to have working prototypes to prove the larger pipe theory is a good idea. I remember having this same debate on S/F about 5 years ago when I had a 3" uper intake pipe on my car, and people were trying to tell me that they didnt think it would work, because of the same theory. I was driving on what was suppose to be a non supported theory. Then Steve from New Jersey bought my IC setup to swap into his stock location, and was inpressed with the resposnse from a bolt on turbo upgrade from S/S I think. When you talk of air velocity, and cfms traveling x feet per second you are slowing down the speed of air traveling trough the larger pipe without actually knowing if the speed is slower or not. That seems to be a flawed test theory, because you don't know for sure if the larger pipe is slowing the air down or not. You are assuming that the air in the larger diameter pipe is slowing down, with out actually knowing this for sure. If the turbo is making enough air volume to keep up with the increased diameter size your theory would be unsubstanciated, because the constant air flow would not slow down, but increase due to the less restrictive pipe size. I think that since the air volume is higher on a 500+RWHP turbo, and the air veleocity is extremely higher the speed remains the same, and that the time it enters the smaller opening of the 2.5" pipe it is bottle necked, and slows down because of the passage ways is cramped like a 3 lane highway during rush hour. When Ian changed the pipe to a larger diameter the bottle neck out of the turbo was reduced when the 3" pipe was installed, because now the three lane highway became a 5 lane highway with the same air volume, and that volume was able to travel out unrestricted, which inturn increased throttle response.:naughty: :evil2: ::fundy::

 

[MRSUPRA]

(A little off the topic).Does anyone know who has the best prices on the GT4067DBB turbo?

 

[QWIKSTRIKE]

(A little off the topic).Does anyone know who has the best prices on the GT4067DBB turbo?

Try DBsupra...Also off topic is that I may want to go a 70mm ballbering flavor in the future since my 67 spools so damn good. Way in the furture though.:naughty:

 

[QWIKSTRIKE]

I'm using 3" in and out and actually saw a drop in spool when I changed from 2.5" (from 2200/1psi to 1900/1psi with the 3")

Always a show off...why didnt you tell me this earlier. Now I may want to go 3" too be just like you. I am truely shocked that since we have been good buds you did't tell me this tid bit of info sooner Ian.:biglaugh: :nono: lol

 

[IJ.]

Ant: Bud maaaateee pal !!

I posted it here somewhere after I changed over and was stunned at the difference.

I'd changed a LOT in my motor for the big IC with the idea it was going to be laggier than before but in hindsight I'd guess it would be damn close to the same response curve it's just the lighter crank assembly lets it climb the Tq curve much sooner.

 

[starscream5000]

I do understand your reasoning here, my debate is based on equations of how to calculate velocity and an engine's volumetric output under specific boost settings. The only real way to prove it, like you are talking about, is with real world experience on the dyno. I think that you'll find that ball bearing turbos are completely different beasts compared to regular turbos, like Ian has demonstrated with his instaspool . I think after seeing the results of Ian's turbo, that I will most likely opt for the BOSS ball bearing series turbochargers instead of their regular versions (I'm only going for a safe tune of 450-500 HP) as their prices have gotten even more affordable, plus the CHRA's are now rebuildable by ITS.

 

[QWIKSTRIKE]

Ant: Bud maaaateee pal !!

I posted it here somewhere after I changed over and was stunned at the difference.

I'd changed a LOT in my motor for the big IC with the idea it was going to be laggier than before but in hindsight I'd guess it would be damn close to the same response curve it's just the lighter crank assembly lets it climb the Tq curve much sooner.

Dunno how I missedd that info....I always thught I was spying on you every step of the way too.

 

[QWIKSTRIKE]

I do understand your reasoning here, my debate is based on equations of how to calculate velocity and an engine's volumetric output under specific boost settings. The only real way to prove it, like you are talking about, is with real world experience on the dyno. I think that you'll find that ball bearing turbos are completely different beasts compared to regular turbos, like Ian has demonstrated with his instaspool . I think after seeing the results of Ian's turbo, that I will most likely opt for the BOSS ball bearing series turbochargers instead of their regular versions (I'm only going for a safe tune of 450-500 HP) as their prices have gotten even more affordable, plus the CHRA's are now rebuildable by ITS.

Hell yeah....I cant believe how responsive the ball bering units are. My GT4067r spools as "Qwik" as the smaller gt4088. Talk about lagg....what lagg. Just get tuned no more than 11.7 to run WOT 20psi boost.:biglaugh:

 

[starscream5000]

I was actually looking to start it out around 11.3-11.7, so we're pretty much on the same page here

 

[IJ.]

SS5: I used to do all of the math but the GT series of turbo's have made all of that info obsolete

Back in the day a 700 crank hp turbo on a 3.0L motor might have made power from ohhh 6500>7000 and been a light switch the 3540R is just amazing how drivable it is even with the 1.06ar turbine to let it breathe up top.

Ant: LOL can't even remember where I posted it

My MoTeC has "antilag" as well but I don't think I'd ever need it.

 

[Boosted Supra]

Not sure if my input counts but....I been running 20psi on 93oct with my SP63 ever since I had it installed. I never had a problem except in the hot summer days (Eric (Zazz) explained that). I will however advise you to put a lower psi spring in there because sometimes in FL it gets kind of chilly. The cold weather will spike you up to mid 20's psi and cause harm to your engine.

A close friend on mine blew his 7M (built like yours) with his 20psi spring in the cold weather trying to race me. His boost spiked up to 25psi, detonation was heard and engine was finished. Also, he was on vpc/afc. If your on aem, I suppose you can adjust it for colder climates??

FYI, I'm using an HKS GT W/G with a 1 bar spring

 

[QWIKSTRIKE]

Not sure if my input counts but....I been running 20psi on 93oct with my SP63 ever since I had it installed. I never had a problem except in the hot summer days (Eric (Zazz) explained that). I will however advise you to put a lower psi spring in there because sometimes in FL it gets kind of chilly. The cold weather will spike you up to mid 20's psi and cause harm to your engine.

A close friend on mine blew his 7M (built like yours) with his 20psi spring in the cold weather trying to race me. His boost spiked up to 25psi, detonation was heard and engine was finished. Also, he was on vpc/afc. If your on aem, I suppose you can adjust it for colder climates??

FYI, I'm using an HKS GT W/G with a 1 bar spring

Why not count your input....you offer valid information ....You have done it right. I've seen you out doing it driving besides me so you have a good solid valuable input. AEM gives more precise management over all variables. Hopefully our friend will be back soon.

 

[Doward]

Qwik, you can't possibly compare electron flow through an electronic system to air flow through a fluid system - two totally different beasts

I do have to correct you on one small thing -

Detonation isnt caused by bring riched its caused by being lean.

Detonation is caused by a spontaneous combustion of the fuel, instead of the smooth, steady burn that you are wanting. What causes the detonation can vary between running too lean or hot spots in the combustion chamber.

Want to avoid detonation? Polish the chambers, and keep an eye on EGTs.

Pre-ignition, on the other hand, is what a lot of people mistake for detonation - pre-ignition is where the air/fuel mixture is lit too early - whether by those same hot spots as can cause detonation, or by actually firing the spark plug too early.

Now, running the engine richer than needed will act to cool the combustion chamber down - but you will also start building up carbon, washing down the cylinder walls (if taken to an extreme), and losing power.

I propose that to run 20+psi on pump gas, one must control the quality of the gas, run just conservation of MBT, do everything possible to ensure no rough spots that can heat up in the combustion chamber (remember, the top of the piston is part of that combustion chamber!) and keep a very vigilant eye on EGTs of ALL 6 cylinders.

That's what I'll be doing, anyway. :dunno: I'm planning on building a display to monitor all 6 cylinders for deviation from one another. :naughty:

 

[starscream5000]

John, have you see Ron R's exhaust manifold?

 

[Doward]

A thing of beauty, isn't it?

Here's an interesting read I found - talks about a lot of what I'm alluding to, but seriously indepth.

*WARNING* Don't bother reading it if you don't have 20-30 minutes to kill

http://www.contactmagazine.com/Issue54/EngineBasics.html

 

[Junior]

disclaimer: I don't KNOW that this will work, as I've not done it, but I've hypothesized about it.

E85 is your answer. stuff is between 100 and 105 octane. you should be able to run without detonation at that boost level on this fuel. HOWEVER, your fuel system will need an overhaul, and your engine management will throw a fit, you'll need to run approximately 40% richer, I'd start at 55% richer and work your way back. it needs ALOT of fuel, which will need bigger injectors, bigger pump, not to mention the reduced fuel mileage.

This is part of why I'm so excited about E85 getting up here, I'll be building a project for it as soon as it gets here.

 

[tissimo]

boost cut will eleminate boost spikes if it happens.. simply set it to 21 psi..