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Thread: Questions About Max Power With Totally Stock Engine?

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Posts: 1-10 of 38
2009-01-16 23:26:20
#1
Questions About Max Power With Totally Stock Engine?
Hey guys I am new here to this forum and I live in California and it looks like this site should have everything that I am gonna need for my next project. My last car was a 92 240sx that i converted into a s13 silvia drifter with a blacktop sr20det and I intalled every bolt on there was but I ended up selling it because of all the heat I was taking from the cops all the time, and now i drive a nissan titan because I just love nissans. Ok on to my project that I am building and my question. I am building a mid travel dual purpose sand and desert buggy and i dont want to use a subaru or a v6 or a vw motor so i decided to go with the pulsar gtir engine because i have never seen it done and I called a place that makes adapter plates to mount it to a built vw 091 transaxle and they carry a kit that works with either front or rear wheel drive sr motors. Now my question is what made me go with the pulsar motors is that they come with a t28 turbo and a nice size top mount intercooler and 440cc injectors unlike the blacktop rearwheel drive sr20det I had in my s13 with a t25, 370cc injectors and a little crappy side mount intercooler. so in its stock form with stock intercooler what power can be had out of the gtir motor? I want to put down between 275-300 horsepower.
2009-01-17 04:56:08
#2
275-300 WHP with everything stock is not too much trouble.

The better question is, why are you leaving it all stock? =]

FYI: the 275-300 WHP can be had from any old DET without any trouble (might want to grab a T28 though), and you don't have to deal with individual throttle bodies, and higher cost / low availability of GTi-R parts.
2009-01-17 18:00:18
#3
Well Ben I have already done a silvia conversion to my last car (92 240sx) with a
blacktop sr20det. here are my reasons for leaving it stock.

A: transaxle i have to use is a volkswagen bus 091 trans and having one fully built will cost about $2700-$3000 and the max power it will handle is 300 horsepower. Anything above 300 then i have to step up to a mendeola trans and the cheapest one they make will only handle up to 350 horse and it is $7000.00 and that is way out of my price range for a gear box.

B: the buggy is only going to weigh about 1400 pounds and 300 horsepower is going to be more than enough.

C: reliability is what i want and if I can get 275-300 out of it reliably without touching anything then thats great.

And also the reason I want the gtir motor over a rwd sr20det is the price is usually a little less than an old redtop sr20det, it already comes with a t28 turbo with larger injectors and it comes with the top mount intercooler which I would have to custom make with any other sr20det and on the gtir it is exactly in the place i want it to be on top like the subarus so i can run a custom scoop into the intercooler. the t28, injectors, and intercooler alone that i would have to buy for the rwd sr20det would be well over $1000 more plus all the custom piping when it everything i would change already comes stock on the gtir.

so what do i need to do to get 300 horsepower out of the stock engine? would i be able to bump the fuel pressure up to 59 lbs. and crank the boost up to 15psi with about 2 feet of 3" piping out of the downpipe with no muffler and a nice intake with the stock ecu or should i have it chipped?

HERE IS A LINK TO THE BUGGY THE ENGINE WILL GO INTO

TUT TECH RACING -> Dual Sport Cars for Sale.
2009-01-17 20:09:03
#4
the t28 will need to be rebuilt with the 360 deg. thrust bearings, and everything else will hold up, although i might warn you that the stock bottom will hold 600hp, except for the bearings, i've seen stock setups eat bearings (literally) like butter. the inj. are good for 350ish and the tune will be good as long as you bump up the fuel pressure.
2009-01-17 20:30:34
#5
Originally Posted by gti-r93
the t28 will need to be rebuilt with the 360 deg. thrust bearings, and everything else will hold up, although i might warn you that the stock bottom will hold 600hp, except for the bearings, i've seen stock setups eat bearings (literally) like butter. the inj. are good for 350ish and the tune will be good as long as you bump up the fuel pressure.


So you are saying that the t28 in factory trim will not handle 275-300hp @ 15psi of boost stock? and i should have it rebuilt with 360 degree thrust bearing before cranking up the boost?
2009-01-17 23:40:23
#6
18psi i didn't hit 300 or at least i don't think i did, i never dynoed it but i only did a 13.5 in the 1/4,(on a fwd) but with 14psi i did a 13.o in the 1/4(4wd),

i strongly don't reccommend going over 15psi on a stock turbo or with stock bearings in the block, but that is just me, you can put some acl race bearings for under $250 and i was quoted 360 to rebuild a t28 with the 360 deg. thrust bearing, with that done you should reach 300-350hp i think. but that is me judging on the searching i have done, if you lokk at my other thread i just completely went over board with my build and i'm hoping for high(or now a days moderate) hp.
2009-01-18 17:24:54
#7
I ran 15psi on my t25 on my stock de and ran a 13.0@110mph. I would run 18psi on the stock t28 and see what happens. it may not last long, but will definitely give you more power and better times then my t25. Most guys running the t28 run low 12's@ 114mph.

And BenFenner whats wrong wrong with the instant throttle response of the ITB's???
2009-01-18 17:46:46
#8
Originally Posted by GR8WHITE
a volkswagen bus 091 trans and having one fully built will cost about $2700-$3000
Just curious, and I'm sure I'm sounding stupid here but, what's the price of a modern Porsche transaxle, and more importantly will it fit/can it be used?

Originally Posted by GR8WHITE
the reason I want the gtir motor over a rwd sr20det is the price is usually a little less than an old redtop sr20det, it already comes with a t28 turbo with larger injectors and it comes with the top mount intercooler which I would have to custom make with any other sr20det
I was talking about FWD SR20DETs. Not sure if they can be had cheaper. You're right about the injectors, turbo and intercooler though.

Originally Posted by GR8WHITE
so what do i need to do to get 300 horsepower out of the stock engine?
A way to deliver more fuel, and peferably control spark advance.

Originally Posted by GR8WHITE
would i be able to bump the fuel pressure up to 59 lbs. and crank the boost up to 15psi

(snip)

with the stock ecu or should i have it chipped?
That might be a quick and dirty way to do it, however I'm not familiar with the boost cut-out settings on the GTi-R ECU, nor do I know how well that method will work in practice. I'm sure others in the know can chime in.
You might want to start another thread about that.
And maybe get familiar with the name Calum.
I'm a stand-alone guy, so really all you're going to get out of me is advice headed towards stand-alone engine management. Most everything else seems crude to me. =/

As for making 300 WHP with the T28; there's no reason you can't do that and more if done properly. I am installing a T28 on my car this weekend and have plans of 18 psi and 320 WHP and should get there with no problems.
I will be running progressive boost though. 18 psi all day long on a T28 might be a little much.


Originally Posted by jonwepa
And BenFenner whats wrong wrong with the instant throttle response of the ITB's???
Nothing. Just from a reliability stand-point, they can be annoying to keep adjusting, and can be a pain in the ass to tune with stand-alone if he goes that route. Also I'd be worried about the mechanics taking a beating from the sand.

But that's the only drawback, and in his situation I'd say it's still worth the risk since the GTi-R engine is 95% of what he needs.
2009-01-20 19:34:40
#9
well the 300hp i was looking for was at the crank not the wheels, but it looks like the tranny i have to use will handle 300hp max so i will probably keep it a little more conservative considering 300hp is the absolute max the tranny will hold so now i would like to crank about 280hp stock so maybe with just a fuel pressure regulator and a boost controller set to about 14-15psi should get me where i need to be.

and i already sent a message to calum at the end of last week asking if he can make a tune close to the mines ecu and how much he would charge but i have not heard back from him.
2009-06-06 02:24:03
#10
ever find out about that tune from calum and what they charge Im looking for a flash on my ECU to
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