Hey I recently posted my DYNO in another area on the forum here and someone told me this looks terrible and that something was very wrong with my car. Can you guys look at it and tell me what you think. The reason I posted this was because I feel with my car mods should put me in the 300-360 whp range. The dyno has me at 224hp. Also the smoothing is level 5 on this dyno. I was told the #'s are low on this dyno. However as you see I am about 100 hp shy of what I was aiming for. I just am trying to understand what I need to check on the car. The car feels like it runs great. However I don't know what a 360 whp car feels like. I talked to my tuner and he says the dyno looks normal and that the wavy lines are the internal wastegate trying to keep a steady boost. Please let me know what you guys think. The car has the following mods.

88 RX7 Turbo II

Engine not ported (rebuilt by me 3k miles ago OEM Seals)

BNR Stage 3 at 15psi

Injectors 725/1000

Adaptronic 1080 ECU (Tuned)

Walbro 255

Fuel pump rewire

Greddy FMIC (or so I was told lol)

Fluidyne Radiator

I don't know what to think. Is the dyno just reading low or what could be the issue?
I guess I need to check my compression of motor as it was suggested. It is just hard to get to the spark plugs is all. Also someone mentioned that it could be my throttle body not opening all the way. Just want to get some more ideas and let me know your opinion on that DYNO.

 

if an na car ran 173 then the dyno is not reading low and you have issues(might even be reading high).

your tuner doesn't know what he's doing, or at least isn't honest with you that the car isn't running correctly.

sometimes you will get some waves from wastegate surging but not to that degree, and it is highly undesirable and still not what i would tell someone is "normal"

 

I am not positive it was an NA for sure. I just don't think he had a turbo on that car is all. There was an FD that did 280 I think on the dyno before I put mine on it, but I am not sure what he had done to his car.

 

well the dyno sounds to be rather accurate, regardless your tuner saying that surge is normal, is not.

a stage 3 with your mods list should be doing over 100 horses more than you are. does the dyno seem to be 1/3 low? many people would notice it if so. i regularly get over 330 from a stage 3 with lower boost than that.

does the car feel like i'ts just a kick over stock? or do you have traction issues in 1/2nd and partly third? the latter should be true on street tires if the car is doing around 350whp as it should. a tuner loses nothing by telling you like it is, if they didn't build the car, they actually get to call you back in and charge for a retune a second time. a poorly trained rotary tuner would be skeptical of his own work and say everything is "fine", as this one did because they do not know what the problem is or how to fix it.

many people have told you this, but you keep asking the same question. a better question to ask is where to find someone who can look over your car for issues, repair and tune it properly in your area.

 

I definitely would like to get this issue fixed. Does anyone know any good tuners in eastern Virginia area? Might even be able to take it to NC if not, but I really just would like the performance to add up to what I have put in it.

 

you can ask in the area specific forum down lower on the main forum list. i'm not familiar with that area so i can't recommend someone.

 

ive seen dynos do strange things, the NASA one, infamously is all over the place, i saw a STOCK 89 vette do 12+ runs, and it gained 12-15hp on each run, so it gained 144hp in dyno session, and you think you would notice that driving the car in real life... in real life it is a 175RWHP car.

anyways, if the dyno is correct; then when you look over the car, you are looking for performance problems.

compression test is a good first start, warm it up, and go take it for a drive where it gets to run nicely for a while, then test it. if you're using a piston compression tester, you are looking more for even bounces than an overall number, since you don't have cranking speed.

second, is spark, you need to verify that you have it on all 4 plugs. i saw Rotary Evolution dyno a car, and it dynoed low, and upon investigation, the leading coil was unplugged. if you have spark, you get to check things like the wires (should be under 16k OHMs resistance), and plugs (for 300hp the Japanese would be running colder plugs)

fuel: i assume this is ok, and that you were looking at a wideband or something? as long as you have enough spark, AFR should have very little effect on power.

air flow: this is the heavy lifting part. you need to make sure the throttle is opening, they have that double throttle thing stock, and if it goes bad, the throttles won't open all the way. broken muffler? clogged exhaust? if the IC is a real GReddy, it will flow enough, if its a make maybe not? boost leaks hurt power too, so you need to check for those. air filter big enough? boost gauge working?

 

yep, losing leading ignition can make a car sound like it's running decently but overall you lose about 35% of your total power without it and that is one good place to start checking. improper timing hub and pulley combinations are also a factor but a lot less easy to pinpoint.

 

Ok so compression test shows 90 front rotor and 80 rear rotor. Also told that it is only boosting to 9 psi. I am being told that the low compression is the reason I am only getting 9 psi boost at 5500 rpms. Also I just rebuilt this engine myself with OEM seals. Any idea why compression would be low? I have run the car about 3k miles. So will a rebuild fix my issues? Also the car is overheating some I guess with AC on. So it is shutting down the ignition I guess when that happens. I was told to put the bottom cover back on and foam around my radiator to fill the gaps between the shroud for this. I just want a second opinion. I am about to go buy a hyundai for more horsepower at this pace.

 

90 and 80 psi, could be considered low, but at what rpm was the compression test done( that greatly effects the readings) readings must be near 250rpms, or can be normalized to that what kind of tester was used?


how many miles did u break the engine in gently? did u use brand new housings? did u use new side seals, did u clearance all seals properly? how much step wear id dhte irons have? these can all effect compression on a rebuild.

even if the tune is improper now, u may have flattened the seal springs and lost some compression.

if your dyno was at 9 psi then 220 hp to the wheels isn't super far off

do you have a boost gauge, and wideband gauge in your car?

the undertray shouldbe on, or you will run into heat issues at speed.

 

Try Angel Motorsports. Michael Vargas is awesome and he's in Virginia Beach.

 

So I did use 1 new housing. As far as all the specs I didn't take any. I used all new OEM seals. The compression test was taken by my tuner for me. Yes I have a wideband. The tune is good on the car. The main thing I am curious about is why I couldn't get past 9psi when i had setting on 15psi. My tuner says its a compression issue. Is this true?

 

engine compression doesn't dictate peak boost level much in a rotary, it does affect the RPMs at which the turbo spools though.

my old engine still ran 16psi of boost even when the compression was down around 60psi. a tired engine just spools slower and perhaps a couple psi off peak, that's all. if your tuner is saying the low compression is the reason it's only pushing 9psi, he doesn't know his *** from a hole in the ground about how engines actually work, more rather he just showed me that he has no real world experience and is just taking guesses.



my suggestion, stop using this person.

in fact, i'd suggest not driving the car hard and/or trusting his tune at all, otherwise it may wind up costing you all the work you put into the car, have it double checked by a professional rotary shop/tuner.

 

So I am sure I am not saying it right here, but the hot side of the turbo where the waste gate is was lose. It wasn't closing to make boost. The turbo was pulled off and fixed. It was then free rev boosting to 7lbs. Now the engine is blown. I am getting it rebuilt. I at least wanted to post what the issue was with my DYNO. Thanks to everyone that chimed in.

 

What are you using to control the wastegate? its either that or a boost leak.

 

told ya not to trust that tune.

 

missed that last post by him....