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View Full Version : Sr20 with s15 dbb low hp#


Bnr32gtr
08-12-2013, 11:38 AM
So I have a s13 black top just did a compression test and its seams healthy 150-155 across the board. It Has power fc d, 810cc injectors, s15 dbb turbo and a tune from Je in bmore md it only put down 290whp at 15psi I just thought that was a Lil low I was thinking 330ish what do u guys think also I have grate a/f at wot but when just cruising not in boost I'm seeing 14-15/1 a/f I was thinking this is way lean but is it ok since not in boost? Thanks for the help any input would be grate I plan to get a gtx In less than a year that's why the 810cc

Bnr32gtr
08-12-2013, 11:46 AM
Sorry phone died and can't figure out how to dealt one of the post

nickauger
08-12-2013, 01:16 PM
14-15 AFR is what you want in cruise. 290whp is very acceptable at 15psi , I assume you don't have upgraded camshaft.

Lev
08-12-2013, 01:33 PM
14-15 AFR is a bit on the lean side, but aside from that 290whp from a T28 is very acceptable. To get a reliable 330 you're going to need a better turbo, disco potato or 2871. You could technically get there on a t28, but you'll be pushing it real hard to do it (as psi goes up, lifespan goes down).

jr_ss
08-12-2013, 02:51 PM
In cruise, 14-15AFR is not lean. Stoich is 14.7:1 and that's what the OEM ECU is going to hunt for. The only areas that were most likely touched were in boost timing and fuel maps.

290whp is acceptable and not low by any means. Tom N on here made 310 or so at 17-18psi.

brndck
08-12-2013, 03:29 PM
290 is pretty good for that turbo on stock internals.

To get any more out of it you'll need cams at least.

speedfiend
08-12-2013, 03:43 PM
I had an S15 DBB on my S14 SR with 256/264 cams and an enthalpy tune with 550cc injectors running 15psi. Mine put down right around 295whp with no sort of tweeking done to the tune just straight outta the box and running pretty damn rich at wot. So your right where you should be for the most part. Course the cams led to a little wider flat power band across the rpm range. I bumped the boost up to 18psi for a bit but was unable to get it back on the dyno to see what the numbers were. Ending up breaking the ring land on #1 piston due to my own stupidity and its been down ever since. But I did daily the car for 3 years like that and ended up with close to 130k miles on the motor before it went so I feel I got some good use out of it and it was only a matter of time before it went.
Cameron

Lev
08-12-2013, 03:52 PM
You shouldn't pay too much attention to the horsepower number. Every dyno reads differently. So one guy might tell you he made 330 whp on mild motor with an S15 dbb, but did it on a a hub dyno which tends to read higher. You may then take your similarly build car to a dynojet and only read 285. Is your car less powerful? Not necessarily. The Dynamometer is a tuning tool, it tells you what your car is doing at what RPM, and if it is telling you your car is running correctly, you should be happy.

Tom N
08-12-2013, 04:20 PM
What is a great AFR at wot?

Mine made 301/322 spiking 17psi and settling around 15 with a AFR in the 11.0 range.
Take it to the track and see what your mph is in the 1/4.

Croustibat
08-12-2013, 04:31 PM
What is a great AFR at wot?

Mine made 301/322 spiking 17psi and settling around 15 with a AFR in the 11.0 range.
Take it to the track and see what your mph is in the 1/4.

Ideally you'd want a bit under 12, but 11 is a nice safeguard. If anything goes wrong with your fuelling system with a target of 11, you'd end up in the 12, 12.5 , which you will see and then no harm is done. Going in the 13.5/14 at WOT though, is another story ... EGTs will rise quite fast, det will occur, and the vicious circle may be quite fast to destroy the engine.

Not much HP to grab there anyway. Timing makes power, running richer has the same effect as retarding timing. So if you are running in the 10 AFRs, better go back to 11/11.5 and remove a couple degrees of timing. You wont wash your cylinders AND will lower fuel consumption (the difference in fuel quantity is negligible in regard of cooling, more fuel does not cool more at this point)

My advice is this: unless you are using high octane fuel (high like > 100 ) and can react quickly to a change of fuel quality, dont aim for 12, aim for 11.

Tom N
08-12-2013, 04:34 PM
Ideally you'd want a bit under 12, but 11 is a nice safeguard. If anything goes wrong with your fuelling system with a target of 11, you'd end up in the 12, 12.5 , which you will see and then no harm is done. Going in the 13.5/14 at WOT though, is another story ... EGTs will rise quite fast, det will occur, and the vicious circle may be quite fast to destroy the engine.

Not much HP to grab there anyway. Unless you are using high octane fuel (high like > 100 ) and can tune the car on the spot, dont aim for 12.

Except the car made less hp at 12.0.
It was tuned from high 10's up to 12.0 and it made the most power from 11.0-11.3. On regular pump gas.
I go by what works on the real world.

Croustibat
08-12-2013, 04:43 PM
Your question was "what is a great AFR at WOT", remember ?

12 is a great AFR, but a bit dangerous. I do use it, because i can react on the spot. i make more power at 12 than at 11, because i use 104 octane fuel, meaning i can use the best possible timing - which you cant on regular fuel, and is the reason why you had to go richer.

Anyway the "more power" you got is something a dyno cannot accurately measure. 10-12% deviation is standard on a dyno. You might have had the same result.


Now if you had asked "How do i get the most power on my car", the answer would have been ... "use high octane and map for 12, with the timing to match".

jr_ss
08-12-2013, 04:49 PM
Your question was "what is a great AFR at WOT", remember ?

12 is a great AFR, but a bit dangerous. I do use it, because i can react on the spot. i make more power at 12 than at 11, because i use 104 octane fuel, meaning i can use the best possible timing - which you cant on regular fuel, and is the reason why you had to go richer.

Anyway the "more power" you got is something a dyno cannot accurately measure. 10-12% deviation is standard on a dyno. You might have had the same result.


Now if you had asked "How do i get the most power on my car", the answer would have been ... "use high octane and map for 12, with the timing to match".

If I'm not mistaken, he was referring to the OP's post...

Tom N
08-12-2013, 04:49 PM
Your question was "what is a great AFR at WOT", remember ?

12 is a great AFR, but a bit dangerous. I do use it, because i can react on the spot. i make more power at 12 than at 11, because i use 104 octane fuel, meaning i can use the best possible timing - which you cant on regular fuel, and is the reason why you had to go richer.

Anyway the "more power" you got is something a dyno cannot accurately measure. 10-12% deviation is standard on a dyno. You might have had the same result.


Now if you had asked "How do i get the most power on my car", the answer would have been ... "use high octane and map for 12, with the timing to match".


I'm sorry I was responding to the original poster. He posted he is running a great AFR at wot. Which is meaningless with out saying what his AFR actually is.
So I was asking that.
Trust me I wasn't asking what a great AFR to run is for myself. 12.0 on regular pump gas here doesn't work if you want to make some power.
On race gas I tune closer to 12.5.
I should have quoted him and highlighted where he said that. But I'm on a phone and didn't take the time to be more clear. Sorry.

cotbu
08-12-2013, 05:41 PM
The hp output is good, i did 289hp @ 14psi from the same turbo. You need to run 18psi to see anywhere near 330 with that turbo. I had 555cc injectors at the time.
Cruising AFR's are as well safe, you could go a little leaner, and let the 02 and ecu handle that shyt.

My car actually loves the leaner afr's like 12.2-12.0 but I always tell her, she can't always have it her way!

kojiki88
08-12-2013, 05:52 PM
I have Toda 264 cams, S15 bb turbo at 17psi with an en external Tial wastegate, 740cc injectors, Z32 maf and it made 305RWHP and 296 torque.

Croustibat
08-12-2013, 11:59 PM
I'm sorry I was responding to the original poster. He posted he is running a great AFR at wot. Which is meaningless with out saying what his AFR actually is.
So I was asking that.
Trust me I wasn't asking what a great AFR to run is for myself. 12.0 on regular pump gas here doesn't work if you want to make some power.
On race gas I tune closer to 12.5.
I should have quoted him and highlighted where he said that. But I'm on a phone and didn't take the time to be more clear. Sorry.

My bad.

You should have posted "what is a grate AFR", i would have gotten it that way :p

Bnr32gtr
08-13-2013, 05:12 AM
At wot a/f is 11-11.5/1.thanks for all the input I feel alot better now knowing that I'm in the ball park,with that being said I'm saving for gtx 2876 but I have a peak boost manifold and a 3076 befor I do anything I'm doing arp and a Apexi hg would u guys sell the top mount and 3076 or run what I got? Do u think it will be supper laggy? I really don't want to cam it. On another note at 80mph I'm At like 3500rpm maybe closer to 4k what can I do to get it down under 3k @ 80mph thanks agin I'm going to try to go to the track tomorrow or Friday so ill let u kno what happens.

jr_ss
08-13-2013, 05:34 AM
Change your FD in the rear to a 3.xx some if you want lower rpms. You'll lose acceleration and the car will seem laggier.

codyace
08-13-2013, 07:50 AM
Not much HP to grab there anyway. Timing makes power, running richer has the same effect as retarding timing. So if you are running in the 10 AFRs, better go back to 11/11.5 and remove a couple degrees of timing. You wont wash your cylinders AND will lower fuel consumption (the difference in fuel quantity is negligible in regard of cooling, more fuel does not cool more at this point)

My advice is this: unless you are using high octane fuel (high like > 100 ) and can react quickly to a change of fuel quality, dont aim for 12, aim for 11.

Well said. I think people spend too much time focusing on 'ideal' numbers instead of shooting for where the car works best. Unsure if it's because customers get focused on arbitrary shit numbers that they forget it can be harmful to a car not running in perfect conditions.

Except the car made less hp at 12.0.
It was tuned from high 10's up to 12.0 and it made the most power from 11.0-11.3. On regular pump gas.
I go by what works on the real world.

I think we all can agree that it makes less power at the higher AFR due to less timing though. (Not for your sake, but for anyone reading the responses)

At wot a/f is 11-11.5/1.thanks for all the input I feel alot better now knowing that I'm in the ball park,with that being said I'm saving for gtx 2876 but I have a peak boost manifold and a 3076 befor I do anything I'm doing arp and a Apexi hg would u guys sell the top mount and 3076 or run what I got? Do u think it will be supper laggy? I really don't want to cam it. On another note at 80mph I'm At like 3500rpm maybe closer to 4k what can I do to get it down under 3k @ 80mph thanks agin I'm going to try to go to the track tomorrow or Friday so ill let u kno what happens.

It's going to be laggy, and you're going to need cams to take advantage of the power. Stock cams on that turbo is fighting both spool up and power, and making a setup like that 'no fun'.

Tom N
08-13-2013, 08:00 AM
Of coarse it's running less timing at a leaner AFR. The car is on pump gas. And not E85 pump gas.
To maximize hp on pump gas I found 11.0 range and xx timing to make the most power on my car.
On my DSM's I have to run AFR's in the 10's to maximize hp on pump gas.
You have to find what your set up likes. I can give anyone a great starting point but you will have to fine tune from there for maximum power. There's no magical numbers that fits all set ups. I've said this before.

EsChassisLove
08-13-2013, 09:13 AM
Holy noob central in here.

Tom N
08-13-2013, 11:11 AM
Holy noob central in here.

Wow you must be a wise man with that awesome post.

codyace
08-13-2013, 01:37 PM
Of coarse it's running less timing at a leaner AFR. The car is on pump gas. And not E85 pump gas.
To maximize hp on pump gas I found 11.0 range and xx timing to make the most power on my car.
On my DSM's I have to run AFR's in the 10's to maximize hp on pump gas.
You have to find what your set up likes. I can give anyone a great starting point but you will have to fine tune from there for maximum power. There's no magical numbers that fits all set ups. I've said this before.

\/ \/ \/

(Not for your sake, but for anyone reading the responses)

I know you may know this, but I like putting the obvious out as there are always people searching (well that is debateable around here LOL) and reading posts and never getting good info.