GT35r ok for road race/autox or should I get something smaller?

[Evan K.]

I think a 35R would be too big for road racing if you want to be competitive, even with a 2.3L. I would suggest a 30R at most, but a BB 50trim would be ideal. A 35R is much better suited for drag racing. You'll be fighting lag coming out of the turns and it will hurt your exit speed.

I have a FP BB 50trim and feel that it's more than enough for even the bigger road courses (like Miller in Salt Lake). If I need more power I can run race gas and turn up the boost. I've been running 91 octane and have the boost somewhere around 19 lbs, and that keeps me competitive with some of the modified C6 Z06's I've seen at the track in terms of lap times.

You don't need a big turbo for road racing. You need an efficient (BB) turbo. I think my turbo is perfect for my setup. But if I was on an extreme budget, a 16G would be a good choice too.

As far as lag coming out of corners just get on the gas sooner. That way you are spooled on corner exit or you can drive around lag with tools such as left foot braking.

 

[slipstream808]

^^^ I dunno... something says it just isn't THAT easy. I could be wrong though. *shrug* ^^^

 

[Ludachris]

As far as lag coming out of corners just get on the gas sooner. That way you are spooled on corner exit or you can drive around lag with tools such as left foot braking.

You're still worse off compared to a smaller turbo with all things equal. The only advantage the 35R would have is on the huge road courses with multiple long straights. Most all of the road courses in the US would favor a smaller turbo than the 35R.

 

[talonTSIDriver]

As far as lag coming out of corners just get on the gas sooner. That way you are spooled on corner exit or you can drive around lag with tools such as left foot braking.

Left foot braking will work alright for a single corner, but if you keep doing that, be prepared to end up off track. You need vacuum once in a while for your brake booster. Go out and try it once; keep boosting and pumping the brake pedal, by the 3rd pump your brake pedal is nearly solid.

You're still worse off compared to a smaller turbo with all things equal. The only advantage the 35R would have is on the huge road courses with multiple long straights. Most all of the road courses in the US would favor a smaller turbo than the 35R.

35r at RA, sure!!! But that’s the only track I have been to where "power > handling."

 

[Evan K.]

You're still worse off compared to a smaller turbo with all things equal. The only advantage the 35R would have is on the huge road courses with multiple long straights. Most all of the road courses in the US would favor a smaller turbo than the 35R.

I'm not advocating people go out and buy a 35r for roadcourses. Since he has one already there are ways to mitigate it's size is all.

 

[drivemusicnow]

It's not that the turbo is bad for road racing, look at the AMS TT car.

It's all the things you would have to then do to make the car worth driving with that turbo. For that car to be fun and fast, you'd need lots of aero work, lots of cooling, LOTS of tire, well tuned suspension, lots of brakes, lots of octane, and a whole lot of track time.

Now, it's true that it'd be a helluvalot faster at that point, but before you get your car completely built, it would be... annoying to drive.

 

[talonTSIDriver]

It's not that the turbo is bad for road racing, look at the AMS TT car.

It's all the things you would have to then do to make the car worth driving with that turbo. For that car to be fun and fast, you'd need lots of aero work, lots of cooling, LOTS of tire, well tuned suspension, lots of brakes, lots of octane, and a whole lot of track time.

Now, it's true that it'd be a helluvalot faster at that point, but before you get your car completely built, it would be... annoying to drive.

to sum it all up, LOTS of money!!!!

 

[gob4sho89]

I'll Trade you my AGP L2R bb turbo for your 35r...

 

[Ludachris]

I'm not advocating people go out and buy a 35r for roadcourses. Since he has one already there are ways to mitigate it's size is all.

Gotcha... as long as people realize that they likely won't be competitive with a 35R on a road course, that's the only point I'm trying to get across. You can still have fun but just don't plan on winning many events.

 

[slipstream808]

I'll Trade you my AGP L2R bb turbo for your 35r...

Can you even GET those anymore?

 

[Ludachris]

It's not that the turbo is bad for road racing, look at the AMS TT car.

It's all the things you would have to then do to make the car worth driving with that turbo. For that car to be fun and fast, you'd need lots of aero work, lots of cooling, LOTS of tire, well tuned suspension, lots of brakes, lots of octane, and a whole lot of track time.

Now, it's true that it'd be a helluvalot faster at that point, but before you get your car completely built, it would be... annoying to drive.

The AMS TT Evo is not really a great example. It's a full-on race car with a stroker motor, an AEM EMS, and it's an Evo... it's similar but not the same.

I have a 2.3 stroker in my car but would still only consider going with a 30R if I was to go any bigger, but I don't feel it's necessary. I can easily just run race gas (or E85) and turn up the boost and have all the top end speed I'd need to compete with the fastest TT classes on the track and I'll benefit from better spoolup.

 

[slipstream808]

Oooo! I wanna see Chris vs. AMS. Showdown of the 4g63 to the death!!

J/K. Couldn't help myself.

 

[tsirider13]

I am runninig the 35R, and i love this thing for Roadracing/time attack.

I really think the lag is very minimum for what this turbo can do in a fairly size track. like someone pointed it already this turbo like higher rpms and thats what road racing is about, I would not recomend using this for autox because that would be a totally diferent story.

Anyways, Right now my turbo is of the car (and for sale) wink wink.
I am switching to the HTA 35R, That one would spool alot faster and bring the torque numbers higher I think that would make even happier about 35R's.

-Manuel

 

[BIGMIXX]

the answer to your question....... or. think you know what you should do. imo just sell the one you got, small price to pay for jumping the gun before you did your research. for optimum efficiency & performance in the above mentioned brackets just think it's overkill. 30r 0r a sweet 50trim will probably bring more smiles to your face... either way. knock em dead..

 

[tsunari]

Looks like this discussion has been just about summed up, but I'd like to add that a 30r on a 2.0L for autoX is definitely too large. For road racing . . . it seems to be a nice fit. I can only imagine what it would be like on a 2.3/2.4L motor.

I'd have to double check some logs, but I believe I'm hitting full boost (~20psi) at 4k RPM
and pulling all the way to redline. When you start building/prepping for road racing / time attack / endurance . . . definitely try and pay attention to the finer details of your setup - mainly efficiency (efficiency in cooling, lubrication, etc . . .)

 

[jerseydiver84]

id look into something smaller with hitting boost a lot faster depending on how many mods and how ## car is set up if its not built for a drag car check out the fpbigt28 decent power and quick spool.

 

[UofACATS]

I'll chime in since I was in a similar situation.

I planned my built around my FP3065. I had collected most of the necessary (and expensive) parts, but was still on the stock turbo when I went road racing for the first time. I was all stock except suspension mods.

I came home completely hooked and immediately went about trying to trade my 3065 for a 3052. I tried for the longest time to get an equal and fair trade but it just didn't happen. Just like you, I deemed it unworthy before I'd even tried it.

So I just bolted up the turbo I had. I was convinced that it was going to suck on the track, and everyone told me it was too big. The track BTW is "twisty," but the car was great on the track, even with the "big" turbo.

A couple things to consider. One, the low end grunt and instant torque will not be there. This hurt me in a few places on the course, especially with the stock rev limiter at 7,500. Two, I made up so much ground on the straights it's not funny, It felt like I was cheating. Three, just because you're not at "full boost" does not mean the car is not making any power. And lastly, As with any mod, you will have to get lots of seat time to properly adjust, especially on the road course.

I say bolt it up.

 

[audioextreme]

I am going to say run the turbo. As long as you have the mods to run it properly, and are not just putting it on because your 16G just died. Those are my favorite kind of customers. Run it! I have ran many different turbo's over the years. I started out drag racing, took up some auto cross, and for the last two years gave up everything else to concentrate on road racing. Granted I now have an Evo, I run a 35R and wouldn't run anything else at the moment. The BW stuff is pretty nice though.

Our main problem like others have stated is putting the power down. The car is unbelieveable, but we need to get more tire under the car for next season, and get some additional Areo involved. We can litterally four wheel drift around every turn, which chews up the R6 Hoosiers pretty quickly. A new set every weekend.

 

[jamesfoster]

I will be running the 35r for now, later when I want to be competitive I'll be getting a GT30. Want to see the manifold I'm going to run? It's quite pretty.

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[schemauer]

It sounds like you may be past the point of no return with that turbo, but I'd suggest going smaller if possible. Big boost on the track leads to cooling issues, lack of reliability, the need for bigger brakes, bigger wheel/tire combination, etc.. Things that take the fun out of the whole experience.

That 16g is a perfect start. I'd build the car around that setup first until it is dead reliable before I'd mess with a monster turbo. A light car that is properly set up will be very fast on a 16g.

I had a "small" 16g on my '95 GSX that I ran track days with for many years. I now have an bery close to stock turbo on the '93 FWD Archer car that I use for track days. Stock downpipe, side mount.... At 14 psi it makes about 230 hp at the wheels. The car is always faster then most of the cars in the more advanced run groups - because it is light and the suspension is set up properly. The best thing about it is I'm not constantly fixing something. Come off the track and park it until the next session. You don't need big hp. The big hp EVO's are usually shop cars with unlimited time and pocketbook thrown at them. You can go that route; if you have the time and/or the pocketbook.

 

[Zmann42087]

id look into something smaller with hitting boost a lot faster depending on how many mods and how ## car is set up if its not built for a drag car check out the fpbigt28 decent power and quick spool.

I have the FP Big-28 and its flat out awesome for autocross. There is no better pick out there in my opinion. For road racing, its probably a little on the smaller side for some of the more open tracks. Still not a bad choice though.

 

[Ludachris]

It sounds like you may be past the point of no return with that turbo, but I'd suggest going smaller if possible. Big boost on the track leads to cooling issues, lack of reliability, the need for bigger brakes, bigger wheel/tire combination, etc.. Things that take the fun out of the whole experience.

That 16g is a perfect start. I'd build the car around that setup first until it is dead reliable before I'd mess with a monster turbo. A light car that is properly set up will be very fast on a 16g.

I had a "small" 16g on my '95 GSX that I ran track days with for many years. I now have an bery close to stock turbo on the '93 FWD Archer car that I use for track days. Stock downpipe, side mount.... At 14 psi it makes about 230 hp at the wheels. The car is always faster then most of the cars in the more advanced run groups - because it is light and the suspension is set up properly. The best thing about it is I'm not constantly fixing something. Come off the track and park it until the next session. You don't need big hp. The big hp EVO's are usually shop cars with unlimited time and pocketbook thrown at them. You can go that route; if you have the time and/or the pocketbook.

You bring up a good point about the brake system... that turbo is going to help with high speed straights almost to a fault. A big brake kit will be needed to make that thing stop consistently. I seriously doubt the stock brake system will be up to the task with the straight line speeds he'll be seeing - at least not for long, and not to mention that an under-braked car can be extremely dangerous.

It's funny how people forget about the consequences of a bigger turbo at the road course. Lag and throttle response in the turns is only one factor. The bigger you go, the more work you have to put into all the other systems on the car - braking, cooling, suspension, tires/wider wheels, etc. That's another reason why it's better to go with a smaller turbo, it's cheaper overall.

 

[gixxerdrew]

Hey, familiar faces!

I think an HTA 35R on a stroker would be excellent I have over 450ft/lb torque at 4500 rpms on mine. With a shorty type manifold like the FP one, would spool even faster.

 

[tsunari]

You bring up a good point about the brake system... that turbo is going to help with high speed straights almost to a fault. A big brake kit will be needed to make that thing stop consistently. I seriously doubt the stock brake system will be up to the task with the straight line speeds he'll be seeing - at least not for long, and not to mention that an under-braked car can be extremely dangerous.

Brake ducts, brake ducts, brake ducts . . . My GT30r is too much for twisty courses on GSX brakes and race pads. I have to REALLY concentrate on compressing my braking zones to stay off the brakes as much as possible. I'm hoping to get some brake ducts fabbed up in the off-season to see how much that helps out next year.

But yes- otherwise a bigger brake kit would most definitely help stand up to the heat punishment.

 

[D_Eclipse9916]

Brake ducts, brake ducts, brake ducts . . . My GT30r is too much for twisty courses on GSX brakes and race pads. I have to REALLY concentrate on compressing my braking zones to stay off the brakes as much as possible. I'm hoping to get some brake ducts fabbed up in the off-season to see how much that helps out next year.

But yes- otherwise a bigger brake kit would most definitely help stand up to the heat punishment.

I forgot to weight but I Dont think I went up in weight at all going to the wilwood 13x1.1 kit if your forgoing that for weight. Ive got to fab up some brake ducts too for next season.

I find the problem with 16g/fp28 is you have a much higher intake charge, leading up to higher combustion temps making the same power. We all assume he will be running more boost so more power. Just run the thing at low power, if its a daily driver/track bi*** thats what I would do (Cough cough thats why I run a frank 4). If it was just straight autox, I would get a BB 50 trim at MOST and run only 16-18psi through it.