4AFE Engine: fuel cut or speed limiter?

[Danny289]

Hi guys, I have a turtle car in Toyota family which I took her to drag strip yesterday . (only modification sofar: Home made CAI which provide as much as engine wants! probably up to 5-6 times of OEM and ATI homemad modification ) And proud of my old lady. Ran three times. First time solo!!! Nobody wanted to race with me. I got offer for next two times with 2001 navgator and 1986 5.0 mustang. I lost in both race but proudly! The only reason my old lady lost was fuel cut or speed limiter.The performnace sheet showed in 60 ft and car reaction my car was a head of her competetors. Strip was 1/8 miles and I ended up 0-60 miles with 11.7 sec( my best time) with my 1995 corolla with 210k miles, for last 10 years not touch cluch.... if i don't have the limitation I gaurantee I will improve 0-60 at least by 2.5-3 seconds.fuel cut happened in all three runs 2-3 times you guys know better than me what thats mean in racing mode!
the problems I noticed:
Gear 1: 35 miles: when I hit 35 miles boom like I am hiting a break wall!!!!!
why exact 35 miles? I am saying because I paid attention not matter I floor the gas pedal from taking off or push the pedal gradually. in 35 miles suddenly rpm drops and speedo shows ~25 mph .

Gear 2: it seems around 55~60 miles problem happens . Yesterday in 1/8 track I couldn't go to lower gear than 2 .

Gear 3: I hit 90 miles yesterday without any problem I in my way not in drag strip. I have no idea about limitation
Gear 4: ive drove 108 mph I didn't dare go faster because poor tires, front end and shocks and strunts and windy situtaion
Gear 5. I do not like this gear in racing mode is useless( at least for me)
please tell me which one is in this case fuel cut or speed limiter or...
I will find the solution. Thanks in advance
Daniel

[Danny289]

In this case I know it seems fuel cut is the problem. What I concern is that "35" miles in first gear, and if is fuel cut why it doesn't happen in 3th gear driving 90 mph?
thanks again

[RobMilkshakes]

Doing a bit of quick calculation, assuming you have the c56 transmission, at those speeds that you listed, you would be well above the 6300rpm redline of the 4AFE, so theres good reason that you are hitting fuel cut if thats the case. The 4AFE produces peak power quite a bit before redline so if you are revving it that high, there would truely be no benfit to it....

Also, to be honest, toyota intakes (as well an many stock intakes, especially on smaller engines) are very well designed from the factory, although it may look a bit restrictive, quite often it is found that no true gain is acquired from a CAI, even sometimes, such as on the 5sfe, I've seen cases where power is lost. Sadly they can be a bit of a placebo.

[Danny289]

Originally Posted by RobMilkshakes

Doing a bit of quick calculation, assuming you have the c56 transmission, at those speeds that you listed, you would be well above the 6300rpm redline of the 4AFE, so theres good reason that you are hitting fuel cut if thats the case. The 4AFE produces peak power quite a bit before redline so if you are revving it that high, there would truely be no benfit to it....

Also, to be honest, toyota intakes (as well an many stock intakes, especially on smaller engines) are very well designed from the factory, although it may look a bit restrictive, quite often it is found that no true gain is acquired from a CAI, even sometimes, such as on the 5sfe, I've seen cases where power is lost. Sadly they can be a bit of a placebo.

Thanks for your respond , I was loosing my hope that nobody in celica section answers my question.
Then that is "fuel cut" which I must deal with. It was what I was thinking, but that exact "35" miles made me think ( probably overthinking!) there is something related to speed. Maybe 1995 was so erarly having " seprate speed limiter for each gear" specially in low cost car such as corolla. But 2012 to have this option won't be challenging ( Car companies Listen, if you have not done yet,I am giving you new idea ).But I can not understand why exact 35 miles (overthinking, I know lol).


As you said when hitting 6000 rpm there is no benifit for higher rpm in addition to the overstressing the engine. If you'v experienced "Fuel Cut" you know why I want to deal with that. The game here is not about gaining power but not loosing power. I know I must change gear but it happens to quick before my reaction and I am on 25 miles . And I am sure you know how long it will take I gain the lost "10 miles" driving in lower gear. Oh boy.

I am glad I posted here. You know what you are talking about, Maybe you wanted to be nice saying " a bit restictive.... " No 4AE intake is restictive, but this limitiation doesn't just about intake, I don't know about Celica, but if you pay attention to the Air way which sucks the air to the filter box, you will laugh. It is in the worst place is possible with extermly narrow entery! I am sure Toyota engineers had reason for that.Imo even in safe rpm with that airway there is problem for sufficient air in higher rpm my little modification was around that part. Definately Intake will be replaced or Danny's modification will be done and also head will be replaced or machined( I will be glad to know your opinion). I must do those modification later after dealing with fuel cut I need numbers for compersan because the turbo with avarage 6-9 psi will be on my car later . Toyota must be proud their 18 years product with 210k miles have ~8.5-9sec in 0-60 miles with stock engine. Do you think is there speed limiter in my 1995 corolla ?

c56, transmission hummmm! I didn't know about that thanks for info but I want to say this gearbox is incridible. I don't know about other gearboxes but I don't think you can find many cars can crouse in one gear for 60 miles range ( 30-90 miles in 3th gear). lOOOOL please don't say porsche can crouse from 20 to 150+ miles in gear 5, I know that. Sorry for long post and thanks again.