Yeah he hit it on the head. Like I said in my other post you start with low timing and try and get your a/f in the right ball park. 10.6-10.8 is pump gas territory. On 16 running pump gas a/f ratios is even worse as the fuel is harder to break down which is good when you run a more edgy timing and a/f mixture but bad if your rich. Lean her to atleast 11.6-1 and then see how she reacts. To be honest with race gas you ultimately want to be in the 12.5-1 if you want to be real edgy and milk that thing for power
So leaner AFRs, the 280 cams, jmfab mani , and much more boost and Im sure you will start getting the power levels you find acceptable , and then after that it'll just be a matter of drivetrain holding up I guess.
I agree with everyone. I feel changing the cams, the JM Fab Manifold and leaning her out will help. Plus turning up the boost. I wasnt tuning it so I didnt take notice of the AFR until after the fact. That has already been talked about and were going to lean her out a little to the 11.5-11.7 range to see how she reacts and go from there.
Alex, you definitely need to crank up the boost. Wait till we get that new intake out to you first so you have a manifold on there with a plenum large enough for the high rpm flow you'll need, but once installed get that turbo into it's efficiency range. From the 24psi to 39psi jump, that 15psi netted me 300hp. You'll see what I mean soon enough.
____________________________
Brent @ JM Fabrications
Alex, you definitely need to crank up the boost. Wait till we get that new intake out to you first so you have a manifold on there with a plenum large enough for the high rpm flow you'll need, but once installed get that turbo into it's efficiency range. From the 24psi to 39psi jump, that 15psi netted me 300hp. You'll see what I mean soon enough.
Thanks Brent, I cant wait to get that manifold on there. I hope that, mixed with some other things will get the car where it needs to be. But only time will tell.
I'm a little confused. I just spent the better part of an hour reading through this entire thread. In the beginning you bashed the Polk head but after what is evidently a timing belt tensioner failure, you end up calling the SBR head crappy compared to the Polk head. What gives?
Also, torque falling off like that looks just fine to me as your boost level remained solid. The only time torque stays flat is because of boost creep. If boost pressure stays consistent after peak torque, torque WILL fall and it can fall fast depending on a setup.
I'm a little confused. I just spent the better part of an hour reading through this entire thread. In the beginning you bashed the Polk head but after what is evidently a timing belt tensioner failure, you end up calling the SBR head crappy compared to the Polk head. What gives?
Also, torque falling off like that looks just fine to me as your boost level remained solid. The only time torque stays flat is because of boost creep. If boost pressure stays consistent after peak torque, torque WILL fall and it can fall fast depending on a setup.
Im not exactly sure where you got your reasoning from... If you did read the thread then you would be able to awnser your own question. First, the Polk head was messed up as of last year, but we repaired the head, now it works the way it should. Second, the tensioner failing was never blamed on anything else but itself. The SBR head is still "crappy" and I have been trying to get the problem resolved with Slowboy. The reason I say that head is not as good or equal to the Polk head is this. One, it didnt flow as good, TQ dropped much faster and harder with that head. Second, the ports are far smaller in the SBR head (5mm width, 3mm height on the exhaust side)(1mm width, same height intake side) compared to the Polk head, as well as knife edging on the exhaust ports on the Polk head and none on the SBR head. And yes we have already decided that the TQ is falling slower then most DSM's, so that is a plus.
You do realize that the size of the port doesn't dictate how well it flows right? Going bigger doesn't mean that it's better. Also, knife edging the exhaust divider in the head is just plain stupid. When you knife edge it, it becomes more prone to cracking and having the divider come apart at the edge. That means pieces of aluminum get to go through your turbo. Been there, done that.
I've seen these heads pick up more flow from just a very good valve job versus hogging the ports out. These heads really need an awesome valve job, bowl work and combustion chamber work. The ports themselves need some work, but should DEFINITELY not be where you are focusing most of your interest and work. They really just need a clean up.
For a drag car, you should be running at least 280s if not bigger in regards to cams. I bet most of your "felt" loss of power at the upper RPM band is due to your cam choice, especially if they are HKS 272s which really aren't that good.
____________________________
2007 NASA National Champion TTR Class
Oh and you keep talking about how this head flowed or that one flowed. Did you actually put them on a flow bench to find out concrete data?
What for? He has them on a car which is the constant in the equation. If you put x head on a car and y head on a car and you give proper cool down and don't mess with the tune it's safe to say that if you make more whp with x head then x head flows more than y head. By the way Shep ran 9's with his 272's before changing them
You do realize that the size of the port doesn't dictate how well it flows right? Going bigger doesn't mean that it's better. Also, knife edging the exhaust divider in the head is just plain stupid. When you knife edge it, it becomes more prone to cracking and having the divider come apart at the edge. That means pieces of aluminum get to go through your turbo. Been there, done that.
I've seen these heads pick up more flow from just a very good valve job versus hogging the ports out. These heads really need an awesome valve job, bowl work and combustion chamber work. The ports themselves need some work, but should DEFINITELY not be where you are focusing most of your interest and work. They really just need a clean up.
For a drag car, you should be running at least 280s if not bigger in regards to cams. I bet most of your "felt" loss of power at the upper RPM band is due to your cam choice, especially if they are HKS 272s which really aren't that good.
Your kidding right? Think about it this way next time you say something like port size dosnt matter or effect the flow of a head. With the intake ports hogged out and the exhust ports "stock" where do you expect the rest of the air forced into your motor to go? What goes in must come out somehow. Thats just the way it is. Plus the Polk head has more time into those areas that you mentioned, the SBR head still looks stock asides from the intake ports. And the price tag.
I dont know if this maybe has anything to do with the loss in torque, but usually big turbo's such as the 42r's and such put down larger numbers when their under load correct? Is it maybe because the dyno your using is only registering from only the front wheels? Is it possible that if the or a dyno was reading power and pulling load from all 4 wheels it would put down and or bigger numbers? out of curriosity? And by the way the car is very impressive!!!! Keep up the good work!!!
I dont know if this maybe has anything to do with the loss in torque, but usually big turbo's such as the 42r's and such put down larger numbers when their under load correct? Is it maybe because the dyno your using is only registering from only the front wheels? Is it possible that if the or a dyno was reading power and pulling load from all 4 wheels it would put down and or bigger numbers? out of curriosity? And by the way the car is very impressive!!!! Keep up the good work!!!
The load is still the same, it would make a little less power because of the drivetrain loss however.
ok i'm just curious, dude how can u afford all of this and what do u do for a living, i mean i know all of your mods aren't cheap, i would love to have my car go 9's all day but i have bills to pay first, anyway good lookin put together...
ok i'm just curious, dude how can u afford all of this and what do u do for a living, i mean i know all of your mods aren't cheap, i would love to have my car go 9's all day but i have bills to pay first, anyway good lookin put together...
the names alex, buy you can call him sir sponsors help a good deal with parts but you have to start somewhere. this car wasnt just an overnight happening.
the names alex, buy you can call him sir sponsors help a good deal with parts but you have to start somewhere. this car wasnt just an overnight happening.
, no sir is needed, Alex is fine. I work at KAIZENSPEED. As far as sponsors go I dont have any as of now. Its kind of hard to grab them when the car hasnt been down the track this year. Sponsors want to see results first then comes the help.
You do realize that the size of the port doesn't dictate how well it flows right? Going bigger doesn't mean that it's better. Also, knife edging the exhaust divider in the head is just plain stupid. When you knife edge it, it becomes more prone to cracking and having the divider come apart at the edge. That means pieces of aluminum get to go through your turbo. Been there, done that.
I've seen these heads pick up more flow from just a very good valve job versus hogging the ports out. These heads really need an awesome valve job, bowl work and combustion chamber work. The ports themselves need some work, but should DEFINITELY not be where you are focusing most of your interest and work. They really just need a clean up.
Yup this is true.The ports in a 1g head are aleady huge as it is.
with all due respect xi Talon ix, i was talking to the kat that owns the car, not you, and i dont call anybody "sir"unless i want to, understand this, he's got an awesome ride, but that does'nt give him status for some guy to answer for him, thanks fst91dsm, i appreciate "your" response, now i understand how "u" can have an awesome ride, very cool.....
You get a chance to throw her back on the dyno and mess with teh a/f and swap smim and cams?
Not yet, JM Fab shipped my new IM today and we should see it middle of next week. Then she will be back on the dyno and we can mess with her some more.
I've been following this thread for quite a while. From the pictures, the car looks like it's very well done. Hope you fix all your issues soon. Good luck with it!
I've been following this thread for quite a while. From the pictures, the car looks like it's very well done. Hope you fix all your issues soon. Good luck with it!
Thank you. Hopefully by the end of this next week we will have some very good news.
Just wanted to say.. very nice build! I like your choices and layout alot.
Looking at your graphs, I really wouldnt be too worried. With the intake/cam combo you were running and considering the type of dyno your numbers look right. I think once you start upping the boost the power will start to fall into place. The JMfab manifold should help a bit. I would definitely throw those 280s in there, but even they are a bit smallish for a 4202 car.
Getting a car of this degree up and running is no easy task.. I know I have been through many many various configurations over the past 2 years trying to get my 4202 car perfected. I have wanted to quit and sell it countless times.
I put the car on the scale today just because I was curious... 2610 with me in it, im 160. So not too bad, thats the only updates for now but more will follow this week.
quick question, why 280 cams and not 288, or a custom grind? don't you think 280 are too small for your setup? i know bigger is not always better, correct me if i am wrong but i think with the setup you are running a custom grind is the only way you are going to reach your engines highest potential. other than that keep us posted.
quick question, why 280 cams and not 288, or a custom grind? don't you think 280 are too small for your setup? i know bigger is not always better, correct me if i am wrong but i think with the setup you are running a custom grind is the only way you are going to reach your engines highest potential. other than that keep us posted.
I was just thinking about that today as a matter of fact. When I ordered the 280's the goals for the car we alot less lofty as they are now. As most projects go, mine turned into something bigger and bigger. Were going to see how the 280's do and Im sure they will be upgraded again and again in the future. Plus Im buying a house right now so the pocket book is looking really dry as of late.
sponsors help a good deal with parts but you have to start somewhere. this car wasnt just an overnight happening.
, no sir is needed, Alex is fine. I work at KAIZENSPEED. As far as sponsors go I dont have any as of now. Its kind of hard to grab them when the car hasnt been down the track this year. Sponsors want to see results first then comes the help.
I have been through many many various configurations over the past 2 years trying to get my 4202 car perfected. I have wanted to quit and sell it countless times.
