20 psi??

[thebigspool]

Ok so i was looking into buying a car...nd he says hes running 20psi...with a stock tdo5 side mount..nd stock clutch ...is this even POSSIBLE?? please let me know guys!!

[the_mork]

I'm running 23.5psi on an evo3 16g which is the same frame as a stock 1g turbo. 20psi is possible but it is pushing that turbo IMO. Nevertheless I see no reason not to push a 14b if its what you have. They can be had for $100-$200 when you wear them out or you can upgrade at that point. Other than that the stock sidemount isn't what I would worry about it is the fuel system and the tuning device. The sidemount will tend to heatsoak but I do very well on a Supra SMIC. If the car has a legitimate and worthwhile tuning system and bigger injectors/fuel pump then it simply isn't a problem. That sort of boost can even be sustained by an SAFC though that certainly isn't the route that I would recommend.

[thebigspool]

I'm running 23.5psi on an evo3 16g which is the same frame as a stock 1g turbo. 20psi is possible but it is pushing that turbo IMO. Nevertheless I see no reason not to push a 14b if its what you have. They can be had for $100-$200 when you wear them out or you can upgrade at that point. Other than that the stock sidemount isn't what I would worry about it is the fuel system and the tuning device. The sidemount will tend to heatsoak but I do very well on a Supra SMIC. If the car has a legitimate and worthwhile tuning system and bigger injectors/fuel pump then it simply isn't a problem. That sort of boost can even be sustained by an SAFC though that certainly isn't the route that I would recommend.he says it has a walbro pump..didnt comment on injectors or tunning sys he claims it has a chipped ecu??claims the motor was reuilt and currently has 30k.,,was rebuilt with all oem..

[stageberg]

i would test drive it he prolly has a eprom ecu which is socketed(chipped) but when you drive it the best way to tell if the car can handle that boost is hit well 4th is best i think and if the car jolts which is a big miss fire the car cant handle that boost cuz it aint getting enough fuel which means he didnt replace the fuel pump most likely cuz i ran 22 on a tdo5 with stock injectors blue top 450's fine but had a walbro 255 pump the stock head gasket wont hold up for long running 20 plus (had mine go out running 22) i think stock are rated for 18psi correct me if im wrong but im pretty sure thats right.

[thebigspool]

he said he upgraded to a 195walbro nd i figure it can handle the boost just worried its not safe on the motor??? because i dont feel like buying a car and having replace the head gasket a week later....

[jakea]

i ran 22 on a tdo5 with stock injectors blue top 450's fine but had a walbro 255 pump the stock head gasket wont hold up for long running 20 plus (had mine go out running 22) i think stock are rated for 18psi correct me if im wrong but im pretty sure thats right.

at roughly 2.57 PR, you were likely near 102% IDC at 6000. I'd bet your blown gasket was a series of knock events moreso than a headgasket. member v8killer has ran much more than 20psi on a stock gasket..

to the OP, a sidemount+td05@beyond 2.5PR with the stock intercooler, likely beat and damaged, is a bad idea. Even if he had management, the IAT would be an issue because of the intercoolers efficiency.

[the_mork]

The head gasket can easily take 20psi as long as there isn't excessive knock. I'm running the stock gasket and a fairly conservative tune at the previously mentioned 23.5psi.

Also according to this map the 14b should handle a pr of 2.5 fairly well. Looks to me like a 14b can handle that at up to 70% efficiency with a bigger island at 68% and IMO that isn't too bad. IATs will go up quick on a prolonged run but usually a person doesn't boost like that for all that long. I also expect a 14b to be able to handle that for a quite a while because they are such sturdy turbos and even if it doesn't handle it they are only $100-200 so throw it away and put a new one on or just upgrade. I also think people really underestimate the stock SMIC. I never had an AIT sensor when I had one but my Supra SMIC works beautifully and keeps my temps in a very nice range. A 3rd gear pull showed me just breaking 90* on a summer day at 22psi.


http://stealth316.com/images/td05-14b-raw.gif


Also fwiw when I was looking for the 14b compressor map I accidentally had a look at a 14g map and all I have to say is wow, this would be a great little turbo for a hopped up street machine.

http://stealth316.com/images/td05-14g-raw.gif

[the_mork]

at roughly 2.57 PR, you were likely near 102% IDC at 6000.

Also I don't know how you figured this without knowing the volumetric efficiency of the motor and atmospheric conditions. I can see you saying that anything over 32.3lbs/min would max out a 450cc injector (it will at 11:1) but just knowing a pressure ratio doesn't give you enough information especially if the car has been modified in any way that affects VE such as exhaust, IC piping, air filter, IM, exhaust manifold, porting, etc. I can see having an approximation based on a completely stock hypothetical engine and STP but we live in Wisconsin and no two cars have ever even originally came off of the Normal assembly line with exactly the same VE.

[thebigspool]

thanks guys

[jakea]

Also I don't know how you figured this without knowing the volumetric efficiency of the motor and atmospheric conditions. I can see you saying that anything over 32.3lbs/min would max out a 450cc injector (it will at 11:1) but just knowing a pressure ratio doesn't give you enough information especially if the car has been modified in any way that affects VE such as exhaust, IC piping, air filter, IM, exhaust manifold, porting, etc. I can see having an approximation based on a completely stock hypothetical engine and STP but we live in Wisconsin and no two cars have ever even originally came off of the Normal assembly line with exactly the same VE.

http://www.stealth316.com/2-calc-idc.htm
:). I assumed the variables from past experience and tpical atm conditions

[the_mork]

I was going to mention how that calculator is setup for a 6g72t but I realized that it can be adapted as long as you know some things. The issue is that I'm sure neither of us know the natural capacity for the motor in question but otherwise it is a relatively sound guesstimate. What I object to is the misnomer that PR has anything to do with it.

Also did you use 450cc for the injector size or 398cc? 398cc would be correct in this case because of the difference in the uneditable fuel pressure assumption.

[jakea]

I was going to mention how that calculator is setup for a 6g72t but I realized that it can be adapted as long as you know some things. The issue is that I'm sure neither of us know the natural capacity for the motor in question but otherwise it is a relatively sound guesstimate. What I object to is the misnomer that PR has anything to do with it.

Also did you use 450cc for the injector size or 398cc? 398cc would be correct in this case because of the difference in the uneditable fuel pressure assumption.

I disregaurded the fpr value because I assumed the 255 might bump it up a bit.
PR to me is important, its just another way of saying boost basically.
14.7+xpsi
14.7 = Pressure Ratio.
Either way, we both know 22lbs from a 14b on a stock beat intercooler with no management is bad idea, especially on over worked 100k miles injectors.

[the_mork]

I'm aware of the significance of PR and that it is only significant when used in conjunction with VE when discussing flow, or with flow when considering efficiency. It really isn't a useful number when it stands on its own in the same way that psi isn't generally useful. I think our real disagreement really comes down to significant digits when you mention 102%.

Also a 255 will bump up pressure at idle and cruise but will not increase fuel pressure at WOT.

I'm not trying to be contentious its just that what I would really prefer to avoid is spreading misconceptions (even if it is not actually misinformation) to new DSMers. I'm sure you have dealt with the frustration of misinformed newbs who have misunderstood what someone has said.