why would my MPH drop about 5-6mph and my 60 foot and ET stayed the same from the previous times i went to the track? the only thing ive done different since the last time i was at the track was get rid of the intake pipe and cheapo filter on the turbo and just stuck a k&n straight on the turbo. and cutout part of the rad. support so the filter has direct airflow. oh and i also went from a 56mm throttlebody to a 60mm. previous time at the track was close to 100 degrees and last night was in the 50's.

i dont get it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rota92 &raquo;</TD></TR><TR><TD CLASS="quote">Mine was down when I hurt my motor lol

Are your 1/8 and 1000' on par?</TD></TR></TABLE>

i would have to compare them. but im sure they are a little different. but 1/4 mile ETS and 60 foots the same.

a/f was the same every time at the track. im just comparing the past 2 times i went to the track.. because those both times ive been running 24.5" tires. mph with my 22" was 124 and 120 first time on the 24.5's and then 114 last night.

i dont know what would be hurt on my motor. seems perfect to me as always. i religiously check everything over on it once a week.

all i know is there is no way ive ever been making 400whp. but at the same time people with almost the same setup and turbo running same psi making that. and i also need a new final drive. shifting into 4th at the 1/4 mile sucks.

 

A hurt motor usually explains a drop in MPH. Have it dynoed .

 

could a improvement in 60 foot lower the mph? i went from 1.7 last month to 1.6 60 foots.

i looked over both timeslips and the only thing different between them was the 60 foot and 1/4 mph. the 1/8th, 1000 ft and mph's were the same.

but either way my traps are showing i have a 300whp car if i had 400 like the dyno said then i would be at least very low 11 by now. my weight with me in it is about 2325

 

compression test is the same as it was a couple month back..

not the best but its good numbers except for the variation in the 2nd cylinder

195, 180, 160, 195

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mike93eh2 &raquo;</TD></TR><TR><TD CLASS="quote">

i would have to compare them. but im sure they are a little different. but 1/4 mile
a/f was the same every time at the track. im just comparing the past 2 times i went to the track.. because those both times ive been running 24.5" tires. mph with my 22" was 124 and 120 first time on the 24.5's and then 114 last night.

. shifting into 4th at the 1/4 mile sucks.</TD></TR></TABLE>

can you explain that 1st paragraph better? were you saying that it was going 124 with the 22" slick on ? and the 1st time on 24.5's you went 120mph?

about the shifting into 4th? did you mean 5th ?

you might make 400hp @ the top of your power band. but on the track if you arent making 400 all the way down the track, your mph/et will show.

can you post a dyno graph and what transmission you are running, as well as your rpm limit and shift points. that would help get a complete explanation as to what is going on with your car.


-dave

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DaveF &raquo;</TD></TR><TR><TD CLASS="quote">

can you explain that 1st paragraph better? were you saying that it was going 124 with the 22" slick on ? and the 1st time on 24.5's you went 120mph?
</TD></TR></TABLE>

yes, that is what i meant..

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DaveF &raquo;</TD></TR><TR><TD CLASS="quote">

about the shifting into 4th? did you mean 5th ?
</TD></TR></TABLE>

nope i meant 4th lol.. 24.5" tires on a d16y8 tranny. d's almost have the same gearing as a b18 ls tranny

i even tried going through the traps bouncing off the limiter in 3rd gear but it didnt help any.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DaveF &raquo;</TD></TR><TR><TD CLASS="quote">

can you post a dyno graph and what transmission you are running, as well as your rpm limit and shift points. that would help get a complete explanation as to what is going on with your car.


-dave</TD></TR></TABLE>

this is the only graph i got... its when i got tuned last november.. a few things have changed with the motor as far as upgrades since then also..

im using a d16y8 transmission.....stock gearing, except its racerstev heat treated and obx lsd but still stock gearing. i usually shift at about 8100 rpms.

 

Do you have any logs of the boost towards redline, i'd maybe check for a boost leak of some kind.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nsxmatt &raquo;</TD></TR><TR><TD CLASS="quote">Do you have any logs of the boost towards redline, i'd maybe check for a boost leak of some kind. </TD></TR></TABLE>

i just pressure checked the system a few weeks ago and no leaks.

it reaches 25psi and holds perfectly steady at 25psi all the way to redline.

and btw i forgot to warm the car up before i did that compression check but i think its okay im gonna do a leakdown anyways. but i just dont think anything is wrong with my motor.

 

Pressure check it again, that was 2 weeks ago. Clutch in good shape?

Just go back to the track, maybe it was just a fluke.

 

rota's MPH is anywhere form 141 to 145.

If you ET's are good, don't over think it.

Do you rotate your slicks ?

 

i take it you are probably dropping a good 2500-3000 rpm between shifts ? the smaller tire may be better for you at this point in time, being that your gears are longer.

 

could be the clutch slipping

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DaveF &raquo;</TD></TR><TR><TD CLASS="quote">i take it you are probably dropping a good 2500-3000 rpm between shifts ? the smaller tire may be better for you at this point in time, being that your gears are longer.</TD></TR></TABLE>

no i have full throttle shift..

and my clutch is perfect as far as i can tell. never had a problem with it.

 

try reving it out to at least 8500 and see how fast it goes.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mike93eh2 &raquo;</TD></TR><TR><TD CLASS="quote">

and my clutch is perfect as far as i can tell. never had a problem with it.</TD></TR></TABLE>

Well check it out now, obviously your having some kind of problem with top end power loss. I was trapping 115 with 240whp and your supposedly making 400. Instead of thinking something isn't wrong, go out and check it out. Bigger slicks, big burnout, full throttle shifts, clutch can get hot with a upper gear pull at the end of the track. Do another boost leak check, check all your couplers. Check the fenderliner area to see if those big slicks are rubbing, check the car over for problems it's the only way your going to find out what is wrong.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nsxmatt &raquo;</TD></TR><TR><TD CLASS="quote">

Well check it out now, obviously your having some kind of problem with top end power loss. I was trapping 115 with 240whp and your supposedly making 400. Instead of thinking something isn't wrong, go out and check it out. Bigger slicks, big burnout, full throttle shifts, clutch can get hot with a upper gear pull at the end of the track. Do another boost leak check, check all your couplers. Check the fenderliner area to see if those big slicks are rubbing, check the car over for problems it's the only way your going to find out what is wrong.</TD></TR></TABLE>

you dont think i dont go over my car with a fine toothed comb? i do. every week. but i dont know how you are suppose to check a clutch ??? it doesnt slip one single bit. EVER.

 

did u talk to any other racers at the track that night to see if they were having similar results? if your times were the same maybe there was a problem at the track. i would run it again or take it back to the dyno to see whats goin on...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mike93eh2 &raquo;</TD></TR><TR><TD CLASS="quote">you dont think i dont go over my car with a fine toothed comb? i do. </TD></TR></TABLE>

Your fine toothed comb let about 150whp through it. Might go back and check some of the ideas people here have suggested without just dismissing them saying "That's not the problem". Do a couple of 5th gear roll-on's then pull over and smell for clutch. Do another boost leak check since the last one was weeks ago. Those are things you can do quick and easy before you go to the track again.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nsxmatt &raquo;</TD></TR><TR><TD CLASS="quote">

Your fine toothed comb let about 150whp through it. Might go back and check some of the ideas people here have suggested without just dismissing them saying "That's not the problem". Do a couple of 5th gear roll-on's then pull over and smell for clutch. Do another boost leak check since the last one was weeks ago. Those are things you can do quick and easy before you go to the track again.</TD></TR></TABLE>

like i said there is nothing wrong with the clutch. i have never smelled anything or ever felt any sort of slipping. i run rock steady 25psi. i do not drive the car everyday maybe once a week if that. so that boost leak check i did a couple weeks ago is good.

 

All I can say is that you asked for everyones opinions and you got them. I think you should re-check everything just like everyone is saying. But, also it might of been the track.

Good luck.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HondamanXxX &raquo;</TD></TR><TR><TD CLASS="quote">All I can say is that you asked for everyones opinions and you got them. I think you should re-check everything just like everyone is saying. But, also it might of been the track.

Good luck.</TD></TR></TABLE>

im not complaining. i have checked whatever someone said. as far as the track...could be but i doubt it. its never happened before with me at this track i goto. also havent heard anything else from anyone and their traps being lower than normal..

i just dont think im making 400whp like the dyno said when i got tuned. but the setup and psi compared to others say i should be. but then my track times and trap times say im not.

 

for what its worth, we made more power last year and did not trap as high as we do this year. we make 20hp less this year and trap 10mph higher.

its all about your useable power band. if you are really crossing the traps in 3rd gear, i suggest putting a closer ratio transmission in the car, reving it out more, so when you get into the next gear you are not out of your power band.

 

see mike. this is what happens when you build a car and kno nothing about it. u spent all this money to have JUST a 400hp sohc and ur dumb *** dont even kno how to check your clutch. my advise..... juss kill urself lol

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DaveF &raquo;</TD></TR><TR><TD CLASS="quote">for what its worth, we made more power last year and did not trap as high as we do this year. we make 20hp less this year and trap 10mph higher.

its all about your useable power band. if you are really crossing the traps in 3rd gear, i suggest putting a closer ratio transmission in the car, reving it out more, so when you get into the next gear you are not out of your power band.</TD></TR></TABLE>

i use full throttle shift so it stays in the powerband.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by d16z6Tcrx &raquo;</TD></TR><TR><TD CLASS="quote">see mike. this is what happens when you build a car and kno nothing about it. u spent all this money to have JUST a 400hp sohc and ur dumb *** dont even kno how to check your clutch. my advise..... juss kill urself lol</TD></TR></TABLE>

ok jackass, i guess you cant read the thread?