It's not a big deal as long as you have a ecu like a Apexi PowerFC and fuel system and wideband/tuning AFRs (along with other mods like a intercooler and exhaust).

 

^ Nope, shouldn't be a problem...I'm running my stock twins now @ 15 psi (non-seq) and I made 380 RWHP/315 RWTQ on a ported motor.

One thing I will say is that they've started to smoke a little bit from being pushed so hard, but that's ok...I'm planning on going single over the winter anyway.

 

Today I beat my best times, I ran a 11.16 ET @ 122.25mph with a 1.53 60ft!

My other 3 runs were good too..

11.20 ET 121.98 mph with a 1.56 60 ft
11.25 ET 121.62 mph with a 1.58 60 ft
11.32 ET 121.10 mph with a 1.55 60 ft

Last week my best was a 11.40 @ 121.00

This week I removed about 170 lbs! So all that weight loss got me down to 11.16 from a 11.40 last week which was my best time this year. I removed all the plastic panels/pieces in the car, the carpet, ABS, airbags, the 20lb greddy catback exhaust, radio, windshield wipers/motor, and a bunch of other little things, so the inside was all stripped down.

At the end of last year I ran 11.19 @ 123.80 with a 1.61 60ft. This year I put in 4.77 gears and added the 55lb rollbar, and got the 26" ET Streets instead of the 24.8" Hoosier drag radials. My best this year was 11.40 before I stripped out the interior and everything that made my car 170 lbs lighter which then helped me get down to 11.16. (same amount of boost as last year)

So I think my 4.77 gears are making my 1/4 mile times and mph worse rather than better, but the new gears and tires are helping me get better 60ft times and better 1/8 mile times. 3 of my runs today had better 1/8 mile times compared to my 1/8 mile time when I got the 11.19 last year.

 

Great job!

I'm hoping to run those times next year as well, but I will be single turbo at that point.

 

an rx-7 that can handle such high boost with stock turbos and still hold such low horsepower and still be able to run quarter miles that low is very impressive, keep up the good work

 

those tires and your suspension setup must help alot. I have a T04z turbo pushing 425 @15 psi and I my fastest run was 12.7 @ 12.6psi, but I had stock susp and street tires. boost higher than that, i would just lose traction.

 

The tires help alot, I don't know that the suspension really makes a big difference or not. But I'm sure I could still run 11's with street tires, maybe high 11's. My car doesn't lose traction at the track. (only in 1st gear on street tires on the street). I'm sure you would do much better with the ET streets and maybe some more practice.

 

I'm gonna be putting on some full non-seq turbos, and putting my stock 4.10 gears back in, and then I think there will be a good chance I will finally get a 10.9 . I just recently put in 4.77 gears and they made my 1/4 mile times and mph worse. With a 55lb roll bar added and 4.77's, I could only do 11.40. Then my car lost about 170lbs and I did a 11.16. Last year my best was 11.19 without the roll bar and weight loss, and that was with smaller tires and a worse 60ft time.

 

you should look into putting a bigger single turbo onto the car that would really give you a boost on the quarter mile

 

If you want to increase the output on the Twins under ultra high boost (IE Extreme Heat) you can use straight water injection into the turbos INTAKE.

The Air coming out of the Twins higher then 15psi is (don't have tests on this) over 250F so you can boil water at the 15psi. If you spray a SUPER FINE water mist into the turbos the extreme heat will turn the water into steam (And remove heat pre-IC). Water has a much higher density then air, so if you boil the water it releases its molecules into steam. This steam has a very high volume.

So you have just increased the output of the twins even thow the airflow out of the turbos really never changes

This is a idea that i have wanted to try sometime

 

BNRs?

 

Good point, my suggestion is if you cant afford the BNR's

 

What were you recent 1/8th mile times?

Thanks
David

 

I can't afford to do a single turbo anytime soon, maybe someday.

Thanks for the idea about spraying water into the intake. I can't image intake air temps would be that high just from running a little more boost, my aits are low at the greddy elbow.

Not bnrs.

My 1/8th when I did 11.16 was 7.12 @ 94.54mph. Last year I was going a few mph faster at the 1.8th with the 4.10s, but with the 4.77s I am switching into 4th gear right before the 1.8th.

 

Well once you go above the effectiveness of the turbo the heat that it will produce will sky rocket, that is why people say the twins turn into blow dryers after 15psi.

 

I disagree with all that when it relates to my car and my setup, my car runs better at 18 psi then it does at 15 psi, and I've never blown up the stock motor with like 107k miles.

 

The only way to answer this question with any certainty would be to look at the actual compressor map for the turbo. Does anyone have a map they could post up here?

 

No. But I'm pretty sure no other RX7s with stock seq. twins and stock ported motor with 15 psi or less has come very close to 123 mph or 11.16 in the 1/4 mile, I think it's the additional boost for the most part that gives me these results.

 

hey what type of FMIC piping kit do you have and were did you get it?

 

No offense meant here whatsoever, but you should be running lower times and higher trap speeds with that amount of power, even with factory suspension. I ran a 12.2 @ 119 on factory suspension with 380 RWHP and a 2.19 60'.

 

Its the Greddy 2 row FMIC kit. somewhere online I ordered it, don't remember.

 

I agree, but that was with only 12 psi so he wasn't making that much power.

No offense, but maybe you should be running faster also, I dynoed at 343 and usually between 121-123.8 mph

I'm hoping to make more than 343 when I install my fulll non-seq turbos soon, and I'll be faster in the 1/4 mile of 123.8 last year cause my car is lighter now and adding the non-seq turbos (and I got the 4.10s back in now which are faster at the end of the track).

 

Very impressive...i am now thinking i will complete the car in my garage with stock twins. 4 years ago my best pass on stock twins/ stock motor was 11.7 at 120mph. The car was making 326 at 15psi...

I will say it again...very impressive...

 

Nevermind

 

You are one hell of a driver!!