Another Low Low Dyno
 

Ok, went to get a friend of mine's nitrous bottle filled today and while waiting around we decided to put my car on the dyno. Well It only put down 155WHP on its best run. These are dynojet numbers. I was expecting jsut under 200 or maybe even 200 with my mods. These cars put down 180 to the wheels stock correct? Any ideas on what may be up with my car. I am going to run a compression test on it when it cools down and swap out the plugs which have only about 8,000 miles on them (but it has flooded once). any input would be great. Also, i just turned the DSC off for my first two runs and on the last one i actually pulled the fuse. my runs were 154 and 155. Not sure what the first one was i would have to look.

Coils? Clogged cat?

Do a compression test. If the numbers are low your might need a new engine, which considering your mods will not be easy to obtain from a dealership.

jsut installed the ignition solution about a month ago so i am ssuming the coils are nto bad. and i have an RP supercat with about 8,000 miles on it. So i believe those two things are good to go

yea u might wanna do a compression check thats awfully low.. have u felt a loss of power at all or is the car runing fine?

I read somewhere, that the rx8 has a way of telling if not all the wheels are moving
(w/ or w/ out dsc on) and that it throws the car in a "limp" mode, causing low numbers.

do a search, it was a while back I read about it.

Ok guys, I have just realized that i am mildy retarded. I went and looked at my graphs, and the dyno type was a "superflow" dyno. It puts down numbers similar to a mustang dyno. I new this when i put my car on it, but the guy running the dyno told me he could get switch it over and get a dynojet number out of it by switching off the calculated load. Turns out that he never did this. It says on the graph that it is with the calculated load on it. So, what this all boils down to is 155WHP on a mustang dyno. I believe this would equate to somewhere around 190 on a dynojet. I will still try to get a copy of the graph on here just for the hell of it.

PS. Yes, the DSC can have an affect on the dyno. Thats why the button was pushed and held for the first two runs, and i pulled the fuse for the last run.

Mmmm... I don't know man. Doesn't explain everything. I mean, for a Mustang dyno, you usually use a 10% correction factor to compare to a dynojet. Do the calc on 155whp and you're still only seeing ~170whp. Might want to take it to the track and see if you can trap 94-95 mph. That would prove you're making more power than 170whp.

Also, what gear were you using for the pull?

You'd have to post up the graph for us to see if anything looks weird. Dyno's aren't really a great way to get an absolute power number. they're a good tool to see how your car is performing and what impact mods have. It's best used to make relative comparisons not absolute.

I was finding posts on here where people were pullin 145WHP on a mustang and aroudn 180 on a dynojet. have to do a search again to find it. Plus this weekend did a pull from about 70 with a car that dynoed at 197 on a dynojet and we were dead even. So the trap speed should be about right. Also i thought it was around a 20% correction factor on the dynos. i will get the graph on here tonight, i have jsut been way to busy

different dynos are calibrated differently. That's why once you get a baseline, when you want to hit the dyno again, you need to to visit the same machine.

You can calibrate a mustang dyno to give you similar results to a dynojet, so don't be too quick to assume one is 10% over another.

Also don't be too sure to discount the coils since they're brand new. I had a similar situation with those coils, and didn't look at them for Feb and March because I figured they were blameless.

how would i check the coils. Since they are the Mazsport coils i assume they were good. Also i do not really want to bother with a swap of them if they are good. Once again i am not so sure that they are bad but i will check them if i know how.

It's likely they are fine. I was just saying you cannot ignore them if you have problems, I did that and it wasted a lot of time when they were the cause of my problems.

If you ran side by side with a car making 197rwhp on a Dynojet it sounds as if the dyno was not calibrated correctly. An 40-50rwhp difference would be real obvious in terms of car lengths. Scott

i agree with scott, if my car was 40-50 horse off, there is no way i would stay side by side with that car. granted there are many different factors but if i was down 1/4 of my car's power i think it would be obvious. although, some of it may have been plugs. They were changed not to long ago but the guy pulling it onto the dyno killed it twice backing it on the lift. I was pretty pissed but what can ya do.

Here is a pic of the graph. This is the first pull i did and the lowest HP. The highest HP graph i have looks almost identical, just with 155.6 Hp and 118.2 Tq.

http://i232.photobucket.com/albums/e...h806/Dyno1.jpg

Looks like the VDI didn't open all the way and just caused alot of turbulence in the intake manifold. I have seen this happen a couple of times before and it will loose the last 15-20rwhp because of it.

Vdi?

Yep. You should see your power peak around 8K rpm instead of 7 where you are seeing it now.

Variable Dynamic Intake Effect is the last step of the intake sequence.

so if this was my problem how do i fix it?...lol

ok, so i broke out the manual for the car, did a little research and this is what i found. I hooked up a vacuum pump to the VDI and it operated correctly. then we hooked it up to the car side of the vacuum and it was putting out more then enough to open the valve. I hooked the vacuum line back up to the VDI and had someone watch while i was into the throttle. The VDI opened and closed fine.

Also, i dont think this has anytihng to do with it, but i just plugged the VFAD at the intake just now. It was sitting in the engine bay just open down by the air box.

Would it help if i went out and did a couple logs with the sCANalyser?... if so what would you guys like to see me log specificly

^where did you go for the dyno, I live in west des moines. wonder if you've seen me driving around? :)

i used the dyno in waukee. Lund motors. It was just a freak thing like i said we just happened to be there and a friend wanted me to thow it on the dyno. also, i know the guy that works there and is partial owner so it did not cost me much .

oh yeah, I've heard of them. If you see a sunlight silver 8 with black adr wheels with a polished lip driving around, its probably me.