I just installed AFR 205 heads, a Texas Speed Torquer V2 cam with .232 intake duration, 234 Exhaust, .595 lift on the intake and .598 on the exhaust with 112 lobe separation.
The problem is the engine surges and bucks at between 1200 RPM and 1900 RPM which is highway RPMS in 6th gear.

My mechanic has tuned it twice and I still have the problem.

I have a Vara Ram intake, ported throttle body and ARH 1 2/3" long tubes without cats.

Is this normal or can it be tuned out? I think it is running very rich a low speeds.

The car dyno'd at 450 at the wheels which I think is great but the drivability issues are not good.

Has anyone else had any issues with this cam?

Thanks

 

Keep the engine above 2500 if not 3000 rpms

Cams like that are not meant to be driven like a stock engine.

hell 65 mph is 3rd gear, not 6th like a stocker

 

I have to disagree on this one. That is a very popular daily driven cam and many many people here use it every day with no drivability issues. It is all in the tune. How is your mechanic tuning it? Did they change injectors and not retune the scale. You shouldnt have to rip along at 3K rpms just to maintain a smooth engine.

 

^ I would hope soo.

but 12-1900 rpms seems a bit too low

 

I forgot to add, 42 LB injectors were installed also. I thought this would be a sreet friendly cam and I still think that the problem is in the tune.
Thanks,

 

^^^this^^^

 

I used to cruise at 70 mph and 3,200 rpm with my solid roller, 406, SBC '69 Nova without overdrive. Then I discovered the LS1, electronic fuel injection, and MN6 transmission.

A competent ECM tuner can setup your car to run very well with a larger cam. You should be able to eliminate surging above idle rpm. I'm not going to say it will be 100% stock feeling at all rpm and load points, but a 232/234 cam (and larger ones too) certainly can be used with good success in a daily driver. I just yesterday ordered a cam with nearly the exact same profile as the Torquer V2, and I'll be installing it in my '99 after I get the shortblock cleaned and new cam bearings installed. I too have AFR205 heads, LT headers, Vararam, 30# injectors... Give me a couple weeks to get it all back together and tuned and then I'll email you a copy of my HP Tuners tune for comparison. It shouldn't take much tuning changes from the old 224/230 cam that I have been running the past 95,000 miles.

By the way, is your tuner using a wideband O2 sensor while he is tuning the VE and MAF tables? Is he doing street data collection or simply dyno tuning for WOT conditions?

PS: my '69 Nova now has a fuel injected 408 LS engine too...

 

My 498" solid roller Nova is in the same boat....but then I don't care! I have no problem running it along at 3500.
A modern LS FI engine would be nice for it, but not unless it would go bottom nines. It isn't much of a street car, but it does get driven.

So James, is your guy not able to do part throttle tuning on his dyno?
The more and more I read here, the part throttle and driveability is the toughest part of the tuning process.

Ron

 

find a new tuner

 

this is your problem. you dont need that big of injectors with that cam. 42lb injectors mean they flow 42lbs at 43 PSI which is what they are normally rated at. LS1 runs at 58 PSI which means you are pushing a lot more fuel than that, With that cam you could probably get away with 30lb fuel injectors. Regardless of which ones you use the tuner must tell the computer what lbs injectors you have because it will still fire the larger injector like it is the smaller one.

 

Thanks everyone! I feel a lot better knowing that the problem can be solved without changing the cam.
Needless to say, I looking for a new tuner.

Thanks!

 

Not sure where your at but Dale Clark he is down close to Dayton. He is a great resource I have no problems with my TSV2 good luck.
http://www.tachitupmotorsports.com

 

I have the Texas Speed 228R cam and it's so smooth on the road, it's all in the tune.

 

I have exactly the same set up, T2 cam, 205 heads, 42# flow matched injectors, and Dynamax LTs and I have no driveability problems. 2001 Z.

 

As long as the correct injector data is input into the table......for the LS1 running pressure, the injectors should be fine.
But who knows what the guy did!

Ron

 

I ran that exact same cam when I had a 346 and was cam only. Dr. Phil tuned it and did such a wonderful job my mother could have driven it. It had a slight stumble at low RPM but definitely no bucking. It would surge slightly when I let off, but nothing bad. Find a competent tuner.

 

I have the same cam with stock heads. No driveability issues to speak of if you're above idle while moving. Cruising at 65 in 6th is no problem and silky smooth. My tuner didn't say it was a problem to tune at all. Mods in sig.

 

Hey guys I am the Tech and tuner on the car. Lets be 100% on all the info. the car has a full dyno tune on a load bearing dyno along with a few days of street tuning with a wideband. I thought the car drove great or it would not have left my shop.
It took several test drives and a few phone calls in order for me to even duplicate the problem. The car has a light surge from 1000 rpm to just under 2k only at 5-8% of applied throttle position (around 14% total) at 40-55 kpa. The car idles at 55 KPA.
I am not making light of it or telling Jim to drive around it. Now that I have duplicated it I will fix it. It is just in a spot that is odd to me I never experenced it while tunning the car because it is kind of an odd spot to be in.
I will not claim to be the best tuner out there by any means but I am pretty damn good. I dont think you will find many more who will put this kind of time in a tune for no additional charge.
we have cams of this size or larger in at least 50 street cars with no complaints there is no doubt it is a fine street cam.
We fix a lot of tunes and driveability problems from others. Most install a cam put a car on the dyno spend an hour or two and out the door it goes. This is not that kind of tune.

Dale Clark
Tach It Up Motorsports

 

Great post Dale.

Ron

 

Good Deal Dale. Been a while freind



so what kind of power could this combo make ? ? ?

afr 205s or 215s with a Texas T2 cam hmmmmm


not that I run much below 2500 rpms