no boost in 1st. why?

darkcloud350

New member
I've read around and cant. Figure out why I get no boost in 1st gear put comes in all others.

Running stock boost level 9 psi

If I up the boost to 15 psi will it gain in 1st or will I still be without boost in 1st

I ask because even when my neon srt4 was stock I still hit 10 psi in first but this car feels like it does nothing in 1st
 

awolo

New member
1st gear is mainly there to get the car moving/gears turning/engine revving. So there is not a lot of load on the motor to make a large amount of boost. I see maybe 2-4 psi depending on how I launch. By the time 2nd gear hits, your rpms are up and the motor is ready to put the power down.

I'm no expert though. This is how it was explained to me once. I sure someone with a more concrete answer will chime in.
 

WarTowels

Active member
^Hmm that doesn't sound right to me.

You should EASILY be able to boost in first, second, third, ect.

The stock system is limited to about 5psi in first and second, because first and second put the most load on the engine, right?
Unless you have a boost controller, which will let you build as much boost as your turbo is capable of in first (most likely).

I could easily hit max boost on a CT-26 in first, I guess is all I'm saying.

-Towels
 

IGREGORYI

New member
I was under the impression that engine load in first at a given rpm would be the same as engine load in any other gear at the same rpm, since it is the gearbox which converts raw engine power into more powerthat is sent to the driveshaft or whatever. that is, changing gears doesn make the engine put out more power per se, it converts the raw power output of the engine into more power through the use of gears.... therefore the idea that there would be no load/exhaust gas spooling the compressor due to gear is flawed... i think.. or am i wrong?
 

phattyduck

New member
darkcloud350":20eeep6z said:
I've read around and cant. Figure out why I get no boost in 1st gear put comes in all others.

Running stock boost level 9 psi

If I up the boost to 15 psi will it gain in 1st or will I still be without boost in 1st

I ask because even when my neon srt4 was stock I still hit 10 psi in first but this car feels like it does nothing in 1st
Are you using the factory 'boost' gauge on the gauge cluster maybe?

You should be able to get a decent amount of boost in 1st gear... maybe you have a boost leak, exhaust leak or some other small problem causing slow spooling of the turbo.

-Charlie
 

WarTowels

Active member
Get a 10 speed bike.

Pedal for one mile, in first gear, at 20 mph

Wait, rest.

Now pedal for one mile, in tenth gear at 20 mph.

In this equation:

You = engine
10 speeds on bike = high and low gearing in vehicle

Which one put more load on you?
 

underscore

Well-known member
Stock is 6-7 psi in 1/2, 10-11 in 3/4/5. With a full 3" exhaust, I hit 11 psi in 1/2 and I've never gotten to find out what 3/4/5 hit because I don't want to get my car impounded.

IGREGORYI":1eyqhahc said:
I was under the impression that engine load in first at a given rpm would be the same as engine load in any other gear at the same rpm, since it is the gearbox which converts raw engine power into more powerthat is sent to the driveshaft or whatever. that is, changing gears doesn make the engine put out more power per se, it converts the raw power output of the engine into more power through the use of gears.... therefore the idea that there would be no load/exhaust gas spooling the compressor due to gear is flawed... i think.. or am i wrong?

but the road, drivetrain, and wind all have more resistance in higher gears/at higher speeds.
 

WarTowels

Active member
Now that Im thinking, my example that I quoted isn't a 1:1 comparison. Since the force you exert in each gear (rpm) would be different to get to 20mph. Anyway...
 

phattyduck

New member
WarTowels":66hpvgxi said:
Now that Im thinking, my example that I quoted isn't a 1:1 comparison. Since the force you exert in each gear (rpm) would be different to get to 20mph. Anyway...
Yup. A better way to think of it - how hard it is to get to 5mph on a bike in the lowest gear and the highest gear? The inertia that the engine is working against is divided by the gear ratio (or conversely, the torque the engine puts out is multiplied by the gear ratio).

Really though, on a turbo car its a time issue. 1st gear doesn't last long enough to really spool the turbo - the engine is gaining RPM too fast (and thus ability to take in more air), thus lower boost. (get a better turbo and a higher flowing engine/intake/exhaust and you would get full boost for a bit in first gear)

-Charlie
 

darkcloud350

New member
Ok that was alot of ideas. I do believe that the engine breathes more then enough to spool a Turbo I just had to think long enough. On our stock Turbo we are running bushings witch off the bat means lag. I've experienced lag in a few cars like a 90s Daytona or 88 Chrysler laser they had the same thing in common, no boost in 1st and very slow to gain boost just like ours. Ball bearing turbos are alot more responsive and do spool faster because the free floating bearings. So I guess my last question is has anyone swapped the Turbo to like a 16g off of an eclipse. And tried that. I would like to know everyone's different settups, and if someone is hitting boost in first where you can feel the pull please share what you've done to improve
 

phattyduck

New member
Its not a journal/floating bearing vs. ball bearing issue so much as an overall turbo design issue. More modern materials with better airflow and efficiencies will make a turbo perform better. Better bearings are only a small part of the picture.

If you are going to go through the trouble of changing turbos, I would say go for a nice modern turbo instead of another 20+ year old design.

-Charlie
 

WarTowels

Active member
I would say there is an issue with your car/turbo/something because a CT-26 will easily spool up in first and produce plenty of boost... I used to hit 12psi (which is what I set mine to) with ease. "My" MR2 can hit 15 psi in first and still has RPM to go.

-Towels
 

4rsnduction

New member
phattyduck":3uckq9b9 said:
If you are going to go through the trouble of changing turbos, I would say go for a nice modern turbo instead of another 20+ year old design.

-Charlie

Yeh too right mate,
1st gen turbo's - Like our ct26 - real ancient design - floating bearing type
2nd gen turbo's - Same as floating bearing design but new generation wheel materials mean better spool
3rd gen turbo's - Titanium ball bearings replace floating type - better spool from previous generations
4th gen turbo's - New Borg Warner EFR series - gamma titanium wheel - ceramic ball bearings - real bread winner all round
 

underscore

Well-known member
WarTowels":33j1f1c5 said:
I would say there is an issue with your car/turbo/something because a CT-26 will easily spool up in first and produce plenty of boost... I used to hit 12psi (which is what I set mine to) with ease. "My" MR2 can hit 15 psi in first and still has RPM to go.

-Towels

I hit 11 psi all the time with mine. I'm guessing clogged cat if it won't spool?
 
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