Rx7Boi

I got my G-Tech today and ran a best of 7.1 0-60
then a 7.9 0-60 and 16.1 at 87 mph.
mods are in my sig.
should i be running faster?

my car it doesnt seem to be making much power until 5k, then it jumps....?.... what could it be? bad tps? not tuned? please help!!!!
my motor has 160k on it, i just did the ATF trick and didnt really seem to help.....

i just remembered, my header pipe is bigger then my stock cat pipe, could that be a problem?

The Ace

You shouldnt just be running faster, you should be running MUCH faster...

If you can feel the car jumping to the more powerful rpm band, then you should check fuel supply: is the pump showing bigger voltage, check TPS, check ports. Other than that...I'm bamboozled

Rx7Boi

my six ports are tied open, for the 7.1 time i had to drop the clutch at 5k rpm, i dont spin at all, i have BF comp T/A tires and they grip like *****
I'm gonna change my fuel filter, get a FD fuel pump, send my injectors of to get cleaned, and check my tps..

thanks for the info..

Dyre

GTech 0-60 times can be way off sometimes.

Bambam7

Hey 7.1 seconds for a 88 with only intake and exhaust and assuming you are not a pro drag racing is not bad at all...
You have taken at least a full second from your stock time.
I have a LOT more done, and I am not quite that fast, but I don't have a header yet, and there is something wrong with my fuel system...
Anyways- Here are some suggestions

Pull the sleeves for your six ports right out. You will actually gain a tiny bit of low end back, and you get much better flow at high RPMS The secondary ports have pretty bad flow when the ports are open, but with them removed, will still be experiencing low port velocity in the intake (the reason for bad low end power when open), but it will be a smoother flow, compensating for some of that... High RPM difference is nice though.

Also- Remove your air pump and ACV!! You have a gutted cat, and you don't need the six ports to open, so get those out of there!!!

Finally- get a 2 1/2" preilencer pipe in place or your cat, (make sure it is packed iwth stainless, like a borla...or get one from RB)right back to the y-pipe. The reason for this is -
1-The port mismatch at the header with the smaller flange and tubing diameter of the stock tube is causing a lot of turbulance at high CFM's.
2-With the cat in place, even though gutted, you are losing a good chunk of exhaust velocity, becuase of the expansion area, and killing any exhaust scavenging effect. Rotaries love a perfectly tuned exhaust....

I had to put on a stock pipe with a gutted cat in place of my Bonez race pipe for a while... BIG drop at high RPMS.....
Try launching at 6000 with just a touch of slip (about one step
down from dumping it).

(Try going downhill....)

Good luck

87jap951

Yep, I agree with Bam Bam, Its not bad for a 88 GTU with those miles, from your mods it does sound like you might lose some low end grunt, while picking it back up in the higher RPM's. You might check your plugs to see how the engine is running & if you haven't changed your fuel filter its always a good thing to do anyway. Good luck! I had a 88 Black GTU I loved too!

kliftin

I just ran a 7-7.2 in my 89 with bonez filter and bonez race pipe with cat back. Stock manifold. Thats it. I had my engin rebuilt 8000 miles ago. Pretty good. Im going for more mods soon. I droped clutch at 6000 rpms. 3/4ssec weel spin. It was at night and like 73 or less digrees.

Rx_treme

yeah last night with the mods below i ran a 7.01 0-60 and a 15.58 quarter mile @ 92mph. not too bad. oh i also tried with and without my chip, the best i could run was a 7.4 0-60 and a 16 flat quarter mile. i was impressed to say the least. its not in my sig apparently but its the MD racing Auto X chip.

Rx7Boi

Well, that was my BEST, other then 7.1 my lowest was 7.6 or higher. well i'm gonna call up mindtrain and probably order a pre-silencer.
thank you very much for all your info

i cant take my air pump or ACV out, i still need smog i just swap it with a highflow cat when its smog time, can i run a piston cat for one day for smog? they are so much cheaper...



-- Ian

Maxthe7man

My Gx(SE for you southern folks) pulls about a 7.0-7.2 with a header, RB pre-silencer, dynomax catback, K&N filter, and 225/50/16 rims and tires.
I find that the biggest gain on the N/A comes from the exhaust , then after that, you have to literally beat every extra bit of horsepower out of the car with a hammer, the intake mods, port mods and what not do help but very little, maybe 1 hp here or there. I was reading on the racing beat web site about a new intake manifold for the N/A that is being developed by holley, I feel this is where the next big restriction is after the exhaust, I emailed Holley and they said gains on the intake side showed improvements of 15-25 hp depending on the level of modification to the engine, with the stock exhaust, and ports, they said it would be on the 15 side, which is not bad at all...Max

vosko

iTrader: (4)

i gtech'd my gtu with pacesetter header, bonez intake,bonez hiflow cat, some random SS catback, mazda reman with 20k miles. 0-60 i got 6.6 in the 1/4 in actual racing i got a 16.1@89 . to get the 6.6 i dropped the clutch @ 7000 rpm with regular street tires.

t_mak@mail.plymouth.edu

I ran 15.8 on G-tech and 17.0 on the track. That shows how accurate they are...

edomund

Bambam7 how do you remove the six port sleeves?

mazdaspeed7

Go to the 2nd gen archive. Theres a long thread about it, and it also tells how to do it.